[java][jersey] Remove double brace initialization and some more jersey cleanup (#14783)

* Remove double brace initialization

* Use diamond operator

* Less clutter in generated api classes

* Optimize isJsonMime

* Revert change in escapeString

Skip toString() on string parameters.

* Fix edge-cases

A ServerVariable without enumValues and/or operationServers
with any ServerVariables would lead to invalid code.

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultGenerator.java

@@ -820,6 +820,11 @@ public class DefaultGenerator implements Generator {
             bundle.put("hasServers", true);
         }
 
+        boolean hasOperationServers = allOperations != null && allOperations.stream()
+                .flatMap(om -> om.getOperations().getOperation().stream())
+                .anyMatch(o -> o.servers != null && !o.servers.isEmpty());
+        bundle.put("hasOperationServers", hasOperationServers);
+
         if (openAPI.getExternalDocs() != null) {
             bundle.put("externalDocs", openAPI.getExternalDocs());
         }

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -38,6 +38,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -45,11 +46,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 {{#jsr310}}
 import java.time.OffsetDateTime;
 {{/jsr310}}
@@ -79,80 +83,93 @@ import {{invokerPackage}}.auth.OAuth;
  */
 {{>generatedAnnotation}}
 public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "{{{basePath}}}";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>({{#servers}}{{#-first}}Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>({{#servers}}{{#-first}}Arrays.asList(
-{{/-first}}    new ServerConfiguration(
+{{/-first}}          new ServerConfiguration(
-      "{{{url}}}",
+                  "{{{url}}}",
-      "{{{description}}}{{^description}}No description provided{{/description}}",
+                  "{{{description}}}{{^description}}No description provided{{/description}}",
-      new HashMap<String, ServerVariable>(){{#variables}}{{#-first}} {{
+                  {{^variables}}
-{{/-first}}        put("{{{name}}}", new ServerVariable(
+                  new LinkedHashMap<>()
-          "{{{description}}}{{^description}}No description provided{{/description}}",
+                  {{/variables}}
-          "{{{defaultValue}}}",
+                  {{#variables}}
-          new HashSet<String>(
+                  {{#-first}}
-          {{#enumValues}}
+                  Stream.<Entry<String, ServerVariable>>of(
-          {{#-first}}
+                  {{/-first}}
-            Arrays.asList(
+                          new SimpleEntry<>("{{{name}}}", new ServerVariable(
-          {{/-first}}
+                                  "{{{description}}}{{^description}}No description provided{{/description}}",
-              "{{{.}}}"{{^-last}},{{/-last}}
+                                  "{{{defaultValue}}}",
-          {{#-last}}
+                                  new LinkedHashSet<>({{#enumValues}}{{#-first}}Arrays.asList({{/-first}}
-            )
+                                          "{{{.}}}"{{^-last}},{{/-last}}{{#-last}}
-          {{/-last}}
+                                  ){{/-last}}{{/enumValues}})
-          {{/enumValues}}
+                          )){{^-last}},{{/-last}}
-          )
+                  {{#-last}}
-        ));
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
-      {{#-last}}
+                  {{/-last}}
-      }}{{/-last}}{{/variables}}
+                  {{/variables}}
-    ){{^-last}},{{/-last}}
+          ){{^-last}},{{/-last}}
   {{#-last}}
   ){{/-last}}{{/servers}});
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  {{^hasOperationServers}}
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
+  {{/hasOperationServers}}
+  {{#hasOperationServers}}
+  protected Map<String, List<ServerConfiguration>> operationServers;
+
+  {
+    Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
     {{#apiInfo}}
     {{#apis}}
     {{#operations}}
     {{#operation}}
     {{#servers}}
     {{#-first}}
-    put("{{{classname}}}.{{{operationId}}}", new ArrayList<ServerConfiguration>(Arrays.asList(
+    operationServers.put("{{{classname}}}.{{{operationId}}}", new ArrayList<>(Arrays.asList(
     {{/-first}}
-      new ServerConfiguration(
+            new ServerConfiguration(
-        "{{{url}}}",
+                    "{{{url}}}",
-        "{{{description}}}{{^description}}No description provided{{/description}}",
+                    "{{{description}}}{{^description}}No description provided{{/description}}",
-        new HashMap<String, ServerVariable>(){{#variables}}{{#-first}} {{
+                    {{^variables}}
-{{/-first}}          put("{{{name}}}", new ServerVariable(
+                    new LinkedHashMap<>()
-            "{{{description}}}{{^description}}No description provided{{/description}}",
+                    {{/variables}}
-            "{{{defaultValue}}}",
+                    {{#variables}}
-            new HashSet<String>(
+                    {{#-first}}
-            {{#enumValues}}
+                    Stream.<Entry<String, ServerVariable>>of(
-            {{#-first}}
+                    {{/-first}}
-              Arrays.asList(
+                            new SimpleEntry<>("{{{name}}}", new ServerVariable(
-            {{/-first}}
+                                    "{{{description}}}{{^description}}No description provided{{/description}}",
-                "{{{.}}}"{{^-last}},{{/-last}}
+                                    "{{{defaultValue}}}",
-            {{#-last}}
+                                    new LinkedHashSet<>({{#enumValues}}{{#-first}}Arrays.asList({{/-first}}
-              )
+                                            "{{{.}}}"{{^-last}},{{/-last}}{{#-last}}
-            {{/-last}}
+                                    ){{/-last}}{{/enumValues}})
-            {{/enumValues}}
+                            )){{^-last}},{{/-last}}
-            )
+                    {{#-last}}
-          ));
+                    ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
-        {{#-last}}
+                    {{/-last}}
-        }}{{/-last}}{{/variables}}
+                    {{/variables}}
-      ){{^-last}},{{/-last}}
+            ){{^-last}},{{/-last}}
     {{#-last}}
-    )));{{/-last}}
+    )));
+    {{/-last}}
     {{/servers}}
     {{/operation}}
     {{/operations}}
     {{/apis}}
     {{/apiInfo}}
-  }};
+    this.operationServers = operationServers;
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  }
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
+
+  {{/hasOperationServers}}
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -189,7 +206,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     setUserAgent("{{{httpUserAgent}}}{{^httpUserAgent}}OpenAPI-Generator/{{{artifactVersion}}}/java{{/httpUserAgent}}");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     {{#authMethods}}
     if (authMap != null) {
@@ -235,7 +252,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();{{#authMethods}}{{#vendorExtensions.x-auth-id-alias}}
+    authenticationLookup = new HashMap<>();{{#authMethods}}{{#vendorExtensions.x-auth-id-alias}}
     authenticationLookup.put("{{name}}", "{{.}}");{{/vendorExtensions.x-auth-id-alias}}{{/authMethods}}
   }
 
@@ -830,7 +847,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -889,14 +906,13 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -908,8 +924,8 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -929,8 +945,8 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1222,20 +1238,22 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        {{#hasHttpSignatureMethods}}
+          cookieParams,
-        serializeToString(body, formParams, contentType, isBodyNullable),
+          {{#hasHttpSignatureMethods}}
-        {{/hasHttpSignatureMethods}}
+          serializeToString(body, formParams, contentType, isBodyNullable),
-        {{^hasHttpSignatureMethods}}
+          {{/hasHttpSignatureMethods}}
-        null,
+          {{^hasHttpSignatureMethods}}
-        {{/hasHttpSignatureMethods}}
+          null,
-        method,
+          {{/hasHttpSignatureMethods}}
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1253,7 +1271,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
 
       {{#hasOAuthMethods}}
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1425,10 +1443,10 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/JSON.mustache

@@ -76,7 +76,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -96,7 +96,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -205,12 +205,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/additional_properties.mustache

@@ -13,7 +13,7 @@
   @JsonAnySetter
   public {{classname}} putAdditionalProperty(String key, {{{.}}} value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, {{{.}}}>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/anyof_model.mustache

@@ -99,7 +99,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     // store a list of schema names defined in anyOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public {{classname}}() {
         super("anyOf", {{#isNullable}}Boolean.TRUE{{/isNullable}}{{^isNullable}}Boolean.FALSE{{/isNullable}});
@@ -134,7 +134,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         JSON.registerDescendants({{classname}}.class, Collections.unmodifiableMap(schemas));
         {{#discriminator}}
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         {{#mappedModels}}
         mappings.put("{{mappingName}}", {{modelName}}.class);
         {{/mappedModels}}
@@ -166,7 +166,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
         {{/isNullable}}
         {{#anyOf}}
-        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/api.mustache

@@ -14,6 +14,7 @@ import {{javaxPackage}}.ws.rs.core.GenericType;
 {{^fullJavaUtil}}
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -116,58 +117,84 @@ public class {{classname}} {
   @Deprecated
   {{/isDeprecated}}
   public{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}private{{/vendorExtensions.x-group-parameters}} ApiResponse<{{{returnType}}}{{^returnType}}Void{{/returnType}}> {{operationId}}WithHttpInfo({{#allParams}}{{{dataType}}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws ApiException {
-    Object localVarPostBody = {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}};
+    {{#hasRequiredParams}}
-    {{#allParams}}{{#required}}
+    // Check required parameters
-    // verify the required parameter '{{paramName}}' is set
+    {{#allParams}}
+    {{#required}}
     if ({{paramName}} == null) {
       throw new ApiException(400, "Missing the required parameter '{{paramName}}' when calling {{operationId}}");
     }
-    {{/required}}{{/allParams}}
+    {{/required}}
-    // create path and map variables
+    {{/allParams}}
+
+    {{/hasRequiredParams}}
+    {{#hasPathParams}}
+    // Path parameters
     String localVarPath = "{{{path}}}"{{#pathParams}}
-      .replaceAll("\\{" + "{{baseName}}" + "\\}", apiClient.escapeString({{{paramName}}}.toString())){{/pathParams}};
+            .replaceAll({{=% %=}}"\\{%baseName%}"%={{ }}=%, apiClient.escapeString({{{paramName}}}{{^isString}}.toString(){{/isString}})){{/pathParams}};
-
-    // query params
-    {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<Pair>();
-    {{javaUtilPrefix}}Map<String, String> localVarHeaderParams = new {{javaUtilPrefix}}HashMap<String, String>();
-    {{javaUtilPrefix}}Map<String, String> localVarCookieParams = new {{javaUtilPrefix}}HashMap<String, String>();
-    {{javaUtilPrefix}}Map<String, Object> localVarFormParams = new {{javaUtilPrefix}}HashMap<String, Object>();
 
+    {{/hasPathParams}}
     {{#queryParams}}
+    {{#-first}}
+    // Query parameters
+    {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<>(
+            apiClient.parameterToPairs("{{{collectionFormat}}}", "{{baseName}}", {{paramName}})
+    );
+    {{/-first}}
+    {{^-first}}
     localVarQueryParams.addAll(apiClient.parameterToPairs("{{{collectionFormat}}}", "{{baseName}}", {{paramName}}));
+    {{/-first}}
+    {{#-last}}
+
+    {{/-last}}
     {{/queryParams}}
+    {{#headerParams}}
+    {{#-first}}
+    // Header parameters
+    {{javaUtilPrefix}}Map<String, String> localVarHeaderParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarHeaderParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#headerParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarHeaderParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
     {{/headerParams}}
+    {{#cookieParams}}
+    {{#-first}}
+    // Cookie parameters
+    {{javaUtilPrefix}}Map<String, String> localVarCookieParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarCookieParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#cookieParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarCookieParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
     {{/cookieParams}}
+    {{#formParams}}
+    {{#-first}}
+    // Form parameters
+    {{javaUtilPrefix}}Map<String, Object> localVarFormParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarFormParams.put("{{baseName}}", {{paramName}});{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#formParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarFormParams.put("{{baseName}}", {{paramName}});
     {{/formParams}}
-
+    String localVarAccept = apiClient.selectHeaderAccept({{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}});
-    final String[] localVarAccepts = {
+    String localVarContentType = apiClient.selectHeaderContentType({{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}});
-      {{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}}
+    {{#hasAuthMethods}}
-    };
+    String[] localVarAuthNames = {{=% %=}}new String[] {%#authMethods%"%name%"%^-last%, %/-last%%/authMethods%};%={{ }}=%
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    {{/hasAuthMethods}}
-
-    final String[] localVarContentTypes = {
-      {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}}
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { {{#authMethods}}"{{name}}"{{^-last}}, {{/-last}}{{/authMethods}} };
-
     {{#returnType}}
     GenericType<{{{returnType}}}> localVarReturnType = new GenericType<{{{returnType}}}>() {};
-
     {{/returnType}}
-    return apiClient.invokeAPI("{{classname}}.{{operationId}}", localVarPath, "{{httpMethod}}", localVarQueryParams, localVarPostBody,
+    return apiClient.invokeAPI("{{classname}}.{{operationId}}", {{#hasPathParams}}localVarPath{{/hasPathParams}}{{^hasPathParams}}"{{path}}"{{/hasPathParams}}, "{{httpMethod}}", {{#queryParams}}{{#-first}}localVarQueryParams{{/-first}}{{/queryParams}}{{^queryParams}}new ArrayList<>(){{/queryParams}}, {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}},
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               {{#headerParams}}{{#-first}}localVarHeaderParams{{/-first}}{{/headerParams}}{{^headerParams}}new LinkedHashMap<>(){{/headerParams}}, {{#cookieParams}}{{#-first}}localVarCookieParams{{/-first}}{{/cookieParams}}{{^cookieParams}}new LinkedHashMap<>(){{/cookieParams}}, {{#formParams}}{{#-first}}localVarFormParams{{/-first}}{{/formParams}}{{^formParams}}new LinkedHashMap<>(){{/formParams}}, localVarAccept, localVarContentType,
-                               localVarAuthNames, {{#returnType}}localVarReturnType{{/returnType}}{{^returnType}}null{{/returnType}}, {{#bodyParam}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/bodyParam}}{{^bodyParam}}false{{/bodyParam}});
+                               {{#hasAuthMethods}}localVarAuthNames{{/hasAuthMethods}}{{^hasAuthMethods}}null{{/hasAuthMethods}}, {{#returnType}}localVarReturnType{{/returnType}}{{^returnType}}null{{/returnType}}, {{#bodyParam}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/bodyParam}}{{^bodyParam}}false{{/bodyParam}});
   }
   {{#vendorExtensions.x-group-parameters}}
 

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/oneof_model.mustache

@@ -60,7 +60,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
             {{#useOneOfDiscriminatorLookup}}
             {{#discriminator}}
             {{classname}} new{{classname}} = new {{classname}}();
-            Map<String,Object> result2 = tree.traverse(jp.getCodec()).readValueAs(new TypeReference<Map<String, Object>>() {});
+            Map<String, Object> result2 = tree.traverse(jp.getCodec()).readValueAs(new TypeReference<Map<String, Object>>() {});
             String discriminatorValue = (String)result2.get("{{{propertyBaseName}}}");
             switch (discriminatorValue) {
             {{#mappedModels}}
@@ -132,7 +132,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public {{classname}}() {
         super("oneOf", {{#isNullable}}Boolean.TRUE{{/isNullable}}{{^isNullable}}Boolean.FALSE{{/isNullable}});
@@ -167,7 +167,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         JSON.registerDescendants({{classname}}.class, Collections.unmodifiableMap(schemas));
         {{#discriminator}}
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         {{#mappedModels}}
         mappings.put("{{mappingName}}", {{modelName}}.class);
         {{/mappedModels}}
@@ -199,7 +199,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
         {{/isNullable}}
         {{#oneOf}}
-        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

modules/openapi-generator/src/main/resources/Java/libraries/jersey2/pojo.mustache

@@ -389,7 +389,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     return 0;
   }
 
-  public static final Parcelable.Creator<{{classname}}> CREATOR = new Parcelable.Creator<{{classname}}>() {
+  public static final Parcelable.Creator<{{classname}}> CREATOR = new Parcelable.Creator<>() {
     public {{classname}} createFromParcel(Parcel in) {
 {{#model}}
 {{#isArray}}
@@ -408,14 +408,14 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   };
 {{/parcelableModel}}
 {{#discriminator}}
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  {{#mappedModels}}
+    {{#mappedModels}}
-  mappings.put("{{mappingName}}", {{modelName}}.class);
+    mappings.put("{{mappingName}}", {{modelName}}.class);
-  {{/mappedModels}}
+    {{/mappedModels}}
-  mappings.put("{{name}}", {{classname}}.class);
+    mappings.put("{{name}}", {{classname}}.class);
-  JSON.registerDiscriminator({{classname}}.class, "{{propertyBaseName}}", mappings);
+    JSON.registerDiscriminator({{classname}}.class, "{{propertyBaseName}}", mappings);
-}
+  }
 {{/discriminator}}
 }

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/ApiClient.mustache

@@ -38,6 +38,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -45,11 +46,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 {{#jsr310}}
 import java.time.OffsetDateTime;
 {{/jsr310}}
@@ -79,80 +83,93 @@ import {{invokerPackage}}.auth.OAuth;
  */
 {{>generatedAnnotation}}
 public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "{{{basePath}}}";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>({{#servers}}{{#-first}}Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>({{#servers}}{{#-first}}Arrays.asList(
-{{/-first}}    new ServerConfiguration(
+{{/-first}}          new ServerConfiguration(
-      "{{{url}}}",
+                  "{{{url}}}",
-      "{{{description}}}{{^description}}No description provided{{/description}}",
+                  "{{{description}}}{{^description}}No description provided{{/description}}",
-      new HashMap<String, ServerVariable>(){{#variables}}{{#-first}} {{
+                  {{^variables}}
-{{/-first}}        put("{{{name}}}", new ServerVariable(
+                  new LinkedHashMap<>()
-          "{{{description}}}{{^description}}No description provided{{/description}}",
+                  {{/variables}}
-          "{{{defaultValue}}}",
+                  {{#variables}}
-          new HashSet<String>(
+                  {{#-first}}
-          {{#enumValues}}
+                  Stream.<Entry<String, ServerVariable>>of(
-          {{#-first}}
+                  {{/-first}}
-            Arrays.asList(
+                          new SimpleEntry<>("{{{name}}}", new ServerVariable(
-          {{/-first}}
+                                  "{{{description}}}{{^description}}No description provided{{/description}}",
-              "{{{.}}}"{{^-last}},{{/-last}}
+                                  "{{{defaultValue}}}",
-          {{#-last}}
+                                  new LinkedHashSet<>({{#enumValues}}{{#-first}}Arrays.asList({{/-first}}
-            )
+                                          "{{{.}}}"{{^-last}},{{/-last}}{{#-last}}
-          {{/-last}}
+                                  ){{/-last}}{{/enumValues}})
-          {{/enumValues}}
+                          )){{^-last}},{{/-last}}
-          )
+                  {{#-last}}
-        ));
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
-      {{#-last}}
+                  {{/-last}}
-      }}{{/-last}}{{/variables}}
+                  {{/variables}}
-    ){{^-last}},{{/-last}}
+          ){{^-last}},{{/-last}}
   {{#-last}}
   ){{/-last}}{{/servers}});
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  {{^hasOperationServers}}
+  protected Map<String, List<ServerConfiguration>> operationServers = new LinkedHashMap<>();
+  {{/hasOperationServers}}
+  {{#hasOperationServers}}
+  protected Map<String, List<ServerConfiguration>> operationServers;
+
+  {
+    Map<String, List<ServerConfiguration>> operationServers = new LinkedHashMap<>();
     {{#apiInfo}}
     {{#apis}}
     {{#operations}}
     {{#operation}}
     {{#servers}}
     {{#-first}}
-    put("{{{classname}}}.{{{operationId}}}", new ArrayList<ServerConfiguration>(Arrays.asList(
+    operationServers.put("{{{classname}}}.{{{operationId}}}", new ArrayList<>(Arrays.asList(
     {{/-first}}
-      new ServerConfiguration(
+            new ServerConfiguration(
-        "{{{url}}}",
+                    "{{{url}}}",
-        "{{{description}}}{{^description}}No description provided{{/description}}",
+                    "{{{description}}}{{^description}}No description provided{{/description}}",
-        new HashMap<String, ServerVariable>(){{#variables}}{{#-first}} {{
+                    {{^variables}}
-{{/-first}}          put("{{{name}}}", new ServerVariable(
+                    new LinkedHashMap<>()
-            "{{{description}}}{{^description}}No description provided{{/description}}",
+                    {{/variables}}
-            "{{{defaultValue}}}",
+                    {{#variables}}
-            new HashSet<String>(
+                    {{#-first}}
-            {{#enumValues}}
+                    Stream.<Entry<String, ServerVariable>>of(
-            {{#-first}}
+                    {{/-first}}
-              Arrays.asList(
+                            new SimpleEntry<>("{{{name}}}", new ServerVariable(
-            {{/-first}}
+                                    "{{{description}}}{{^description}}No description provided{{/description}}",
-                "{{{.}}}"{{^-last}},{{/-last}}
+                                    "{{{defaultValue}}}",
-            {{#-last}}
+                                    new LinkedHashSet<>({{#enumValues}}{{#-first}}Arrays.asList({{/-first}}
-              )
+                                            "{{{.}}}"{{^-last}},{{/-last}}{{#-last}}
-            {{/-last}}
+                                    ){{/-last}}{{/enumValues}})
-            {{/enumValues}}
+                            )){{^-last}},{{/-last}}
-            )
+                    {{#-last}}
-          ));
+                    ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
-        {{#-last}}
+                    {{/-last}}
-        }}{{/-last}}{{/variables}}
+                    {{/variables}}
-      ){{^-last}},{{/-last}}
+            ){{^-last}},{{/-last}}
     {{#-last}}
-    )));{{/-last}}
+    )));
+    {{/-last}}
     {{/servers}}
     {{/operation}}
     {{/operations}}
     {{/apis}}
     {{/apiInfo}}
-  }};
+    this.operationServers = operationServers;
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  }
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
+
+  {{/hasOperationServers}}
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -189,7 +206,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     setUserAgent("{{{httpUserAgent}}}{{^httpUserAgent}}OpenAPI-Generator/{{{artifactVersion}}}/java{{/httpUserAgent}}");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     {{#authMethods}}
     if (authMap != null) {
@@ -235,7 +252,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();{{#authMethods}}{{#vendorExtensions.x-auth-id-alias}}
+    authenticationLookup = new HashMap<>();{{#authMethods}}{{#vendorExtensions.x-auth-id-alias}}
     authenticationLookup.put("{{name}}", "{{.}}");{{/vendorExtensions.x-auth-id-alias}}{{/authMethods}}
   }
 
@@ -830,7 +847,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -889,14 +906,13 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -908,8 +924,8 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -929,8 +945,8 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1222,20 +1238,22 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        {{#hasHttpSignatureMethods}}
+          cookieParams,
-        serializeToString(body, formParams, contentType, isBodyNullable),
+          {{#hasHttpSignatureMethods}}
-        {{/hasHttpSignatureMethods}}
+          serializeToString(body, formParams, contentType, isBodyNullable),
-        {{^hasHttpSignatureMethods}}
+          {{/hasHttpSignatureMethods}}
-        null,
+          {{^hasHttpSignatureMethods}}
-        {{/hasHttpSignatureMethods}}
+          null,
-        method,
+          {{/hasHttpSignatureMethods}}
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1253,7 +1271,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
 
       {{#hasOAuthMethods}}
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1425,10 +1443,10 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/JSON.mustache

@@ -76,7 +76,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -96,7 +96,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -205,12 +205,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/additional_properties.mustache

@@ -13,7 +13,7 @@
   @JsonAnySetter
   public {{classname}} putAdditionalProperty(String key, {{{.}}} value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, {{{.}}}>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/anyof_model.mustache

@@ -99,7 +99,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     // store a list of schema names defined in anyOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public {{classname}}() {
         super("anyOf", {{#isNullable}}Boolean.TRUE{{/isNullable}}{{^isNullable}}Boolean.FALSE{{/isNullable}});
@@ -134,7 +134,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         JSON.registerDescendants({{classname}}.class, Collections.unmodifiableMap(schemas));
         {{#discriminator}}
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         {{#mappedModels}}
         mappings.put("{{mappingName}}", {{modelName}}.class);
         {{/mappedModels}}
@@ -166,7 +166,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
         {{/isNullable}}
         {{#anyOf}}
-        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/api.mustache

@@ -14,6 +14,7 @@ import {{javaxPackage}}.ws.rs.core.GenericType;
 {{^fullJavaUtil}}
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -116,58 +117,84 @@ public class {{classname}} {
   @Deprecated
   {{/isDeprecated}}
   public{{/vendorExtensions.x-group-parameters}}{{#vendorExtensions.x-group-parameters}}private{{/vendorExtensions.x-group-parameters}} ApiResponse<{{{returnType}}}{{^returnType}}Void{{/returnType}}> {{operationId}}WithHttpInfo({{#allParams}}{{{dataType}}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws ApiException {
-    Object localVarPostBody = {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}};
+    {{#hasRequiredParams}}
-    {{#allParams}}{{#required}}
+    // Check required parameters
-    // verify the required parameter '{{paramName}}' is set
+    {{#allParams}}
+    {{#required}}
     if ({{paramName}} == null) {
       throw new ApiException(400, "Missing the required parameter '{{paramName}}' when calling {{operationId}}");
     }
-    {{/required}}{{/allParams}}
+    {{/required}}
-    // create path and map variables
+    {{/allParams}}
+
+    {{/hasRequiredParams}}
+    {{#hasPathParams}}
+    // Path parameters
     String localVarPath = "{{{path}}}"{{#pathParams}}
-      .replaceAll("\\{" + "{{baseName}}" + "\\}", apiClient.escapeString({{{paramName}}}.toString())){{/pathParams}};
+            .replaceAll({{=% %=}}"\\{%baseName%}"%={{ }}=%, apiClient.escapeString({{{paramName}}}{{^isString}}.toString(){{/isString}})){{/pathParams}};
-
-    // query params
-    {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<Pair>();
-    {{javaUtilPrefix}}Map<String, String> localVarHeaderParams = new {{javaUtilPrefix}}HashMap<String, String>();
-    {{javaUtilPrefix}}Map<String, String> localVarCookieParams = new {{javaUtilPrefix}}HashMap<String, String>();
-    {{javaUtilPrefix}}Map<String, Object> localVarFormParams = new {{javaUtilPrefix}}HashMap<String, Object>();
 
+    {{/hasPathParams}}
     {{#queryParams}}
+    {{#-first}}
+    // Query parameters
+    {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<>(
+            apiClient.parameterToPairs("{{{collectionFormat}}}", "{{baseName}}", {{paramName}})
+    );
+    {{/-first}}
+    {{^-first}}
     localVarQueryParams.addAll(apiClient.parameterToPairs("{{{collectionFormat}}}", "{{baseName}}", {{paramName}}));
+    {{/-first}}
+    {{#-last}}
+
+    {{/-last}}
     {{/queryParams}}
+    {{#headerParams}}
+    {{#-first}}
+    // Header parameters
+    {{javaUtilPrefix}}Map<String, String> localVarHeaderParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarHeaderParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#headerParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarHeaderParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
     {{/headerParams}}
+    {{#cookieParams}}
+    {{#-first}}
+    // Cookie parameters
+    {{javaUtilPrefix}}Map<String, String> localVarCookieParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarCookieParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#cookieParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarCookieParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
     {{/cookieParams}}
+    {{#formParams}}
+    {{#-first}}
+    // Form parameters
+    {{javaUtilPrefix}}Map<String, Object> localVarFormParams = new {{javaUtilPrefix}}LinkedHashMap<>();
+    {{/-first}}
+    {{^required}}if ({{paramName}} != null) {
+      {{/required}}localVarFormParams.put("{{baseName}}", {{paramName}});{{^required}}
+    }{{/required}}
+    {{#-last}}
 
-    {{#formParams}}if ({{paramName}} != null)
+    {{/-last}}
-      localVarFormParams.put("{{baseName}}", {{paramName}});
     {{/formParams}}
-
+    String localVarAccept = apiClient.selectHeaderAccept({{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}});
-    final String[] localVarAccepts = {
+    String localVarContentType = apiClient.selectHeaderContentType({{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}});
-      {{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}}
+    {{#hasAuthMethods}}
-    };
+    String[] localVarAuthNames = {{=% %=}}new String[] {%#authMethods%"%name%"%^-last%, %/-last%%/authMethods%};%={{ }}=%
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    {{/hasAuthMethods}}
-
-    final String[] localVarContentTypes = {
-      {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}}
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { {{#authMethods}}"{{name}}"{{^-last}}, {{/-last}}{{/authMethods}} };
-
     {{#returnType}}
     GenericType<{{{returnType}}}> localVarReturnType = new GenericType<{{{returnType}}}>() {};
-
     {{/returnType}}
-    return apiClient.invokeAPI("{{classname}}.{{operationId}}", localVarPath, "{{httpMethod}}", localVarQueryParams, localVarPostBody,
+    return apiClient.invokeAPI("{{classname}}.{{operationId}}", {{#hasPathParams}}localVarPath{{/hasPathParams}}{{^hasPathParams}}"{{path}}"{{/hasPathParams}}, "{{httpMethod}}", {{#queryParams}}{{#-first}}localVarQueryParams{{/-first}}{{/queryParams}}{{^queryParams}}new ArrayList<>(){{/queryParams}}, {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}},
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               {{#headerParams}}{{#-first}}localVarHeaderParams{{/-first}}{{/headerParams}}{{^headerParams}}new LinkedHashMap<>(){{/headerParams}}, {{#cookieParams}}{{#-first}}localVarCookieParams{{/-first}}{{/cookieParams}}{{^cookieParams}}new LinkedHashMap<>(){{/cookieParams}}, {{#formParams}}{{#-first}}localVarFormParams{{/-first}}{{/formParams}}{{^formParams}}new LinkedHashMap<>(){{/formParams}}, localVarAccept, localVarContentType,
-                               localVarAuthNames, {{#returnType}}localVarReturnType{{/returnType}}{{^returnType}}null{{/returnType}}, {{#bodyParam}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/bodyParam}}{{^bodyParam}}false{{/bodyParam}});
+                               {{#hasAuthMethods}}localVarAuthNames{{/hasAuthMethods}}{{^hasAuthMethods}}null{{/hasAuthMethods}}, {{#returnType}}localVarReturnType{{/returnType}}{{^returnType}}null{{/returnType}}, {{#bodyParam}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/bodyParam}}{{^bodyParam}}false{{/bodyParam}});
   }
   {{#vendorExtensions.x-group-parameters}}
 

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/oneof_model.mustache

@@ -132,7 +132,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public {{classname}}() {
         super("oneOf", {{#isNullable}}Boolean.TRUE{{/isNullable}}{{^isNullable}}Boolean.FALSE{{/isNullable}});
@@ -167,7 +167,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         JSON.registerDescendants({{classname}}.class, Collections.unmodifiableMap(schemas));
         {{#discriminator}}
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         {{#mappedModels}}
         mappings.put("{{mappingName}}", {{modelName}}.class);
         {{/mappedModels}}
@@ -199,7 +199,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
         {{/isNullable}}
         {{#oneOf}}
-        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf({{{.}}}.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

modules/openapi-generator/src/main/resources/Java/libraries/jersey3/pojo.mustache

@@ -389,7 +389,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
     return 0;
   }
 
-  public static final Parcelable.Creator<{{classname}}> CREATOR = new Parcelable.Creator<{{classname}}>() {
+  public static final Parcelable.Creator<{{classname}}> CREATOR = new Parcelable.Creator<>() {
     public {{classname}} createFromParcel(Parcel in) {
 {{#model}}
 {{#isArray}}
@@ -408,14 +408,14 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   };
 {{/parcelableModel}}
 {{#discriminator}}
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  {{#mappedModels}}
+    {{#mappedModels}}
-  mappings.put("{{mappingName}}", {{modelName}}.class);
+    mappings.put("{{mappingName}}", {{modelName}}.class);
-  {{/mappedModels}}
+    {{/mappedModels}}
-  mappings.put("{{name}}", {{classname}}.class);
+    mappings.put("{{name}}", {{classname}}.class);
-  JSON.registerDiscriminator({{classname}}.class, "{{propertyBaseName}}", mappings);
+    JSON.registerDiscriminator({{classname}}.class, "{{propertyBaseName}}", mappings);
-}
+  }
 {{/discriminator}}
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/ApiClient.java

@@ -36,6 +36,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -43,11 +44,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -70,25 +74,26 @@ import org.openapitools.client.auth.OAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io:80/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://petstore.swagger.io:80/v2",
+                  "http://petstore.swagger.io:80/v2",
-      "No description provided",
+                  "No description provided",
-      new HashMap<String, ServerVariable>()
+                  new LinkedHashMap<>()
-    )
+          )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-  }};
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -125,7 +130,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("petstore_auth");
@@ -163,7 +168,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -751,7 +756,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -810,14 +815,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -829,8 +833,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -850,8 +854,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1143,15 +1147,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        null,
+          cookieParams,
-        method,
+          null,
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1168,7 +1174,7 @@ public class ApiClient extends JavaTimeFormatter {
       final int statusCode = response.getStatusInfo().getStatusCode();
 
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1339,10 +1345,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/JSON.java

@@ -64,7 +64,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -84,7 +84,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -193,12 +193,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,16 @@ public class AnotherFakeApi {
      </table>
    */
   public ApiResponse<Client> call123testSpecialTagsWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling call123testSpecialTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/another-fake/dummy";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", "/another-fake/dummy", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -20,6 +20,7 @@ import org.openapitools.client.model.XmlItem;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -81,41 +82,16 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> createXmlItemWithHttpInfo(XmlItem xmlItem) throws ApiException {
-    Object localVarPostBody = xmlItem;
+    // Check required parameters
-    
-    // verify the required parameter 'xmlItem' is set
     if (xmlItem == null) {
       throw new ApiException(400, "Missing the required parameter 'xmlItem' when calling createXmlItem");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/create_xml_item";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/xml", "application/xml; charset=utf-8", "application/xml; charset=utf-16", "text/xml", "text/xml; charset=utf-8", "text/xml; charset=utf-16");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.createXmlItem", "/fake/create_xml_item", "POST", new ArrayList<>(), xmlItem,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/xml", "application/xml; charset=utf-8", "application/xml; charset=utf-16", "text/xml", "text/xml; charset=utf-8", "text/xml; charset=utf-16"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.createXmlItem", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -146,38 +122,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Boolean> fakeOuterBooleanSerializeWithHttpInfo(Boolean body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/boolean";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<Boolean> localVarReturnType = new GenericType<Boolean>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", "/fake/outer/boolean", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -208,38 +158,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<OuterComposite> fakeOuterCompositeSerializeWithHttpInfo(OuterComposite body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/composite";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<OuterComposite> localVarReturnType = new GenericType<OuterComposite>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", "/fake/outer/composite", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -270,38 +194,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<BigDecimal> fakeOuterNumberSerializeWithHttpInfo(BigDecimal body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/number";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<BigDecimal> localVarReturnType = new GenericType<BigDecimal>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", "/fake/outer/number", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -332,38 +230,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<String> fakeOuterStringSerializeWithHttpInfo(String body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/string";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", "/fake/outer/string", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -393,41 +265,16 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithFileSchemaWithHttpInfo(FileSchemaTestClass body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithFileSchema");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-file-schema";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", "/fake/body-with-file-schema", "PUT", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -459,47 +306,24 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithQueryParamsWithHttpInfo(String query, User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'query' is set
     if (query == null) {
       throw new ApiException(400, "Missing the required parameter 'query' when calling testBodyWithQueryParams");
     }
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithQueryParams");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-query-params";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "query", query)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "query", query));
+    String localVarAccept = apiClient.selectHeaderAccept();
-
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    
+    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", "/fake/body-with-query-params", "PUT", localVarQueryParams, body,
-    
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    
+                               null, null, false);
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * To test \&quot;client\&quot; model
@@ -530,43 +354,17 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Client> testClientModelWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testClientModel");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeApi.testClientModel", "/fake", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.testClientModel", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
@@ -624,83 +422,62 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testEndpointParametersWithHttpInfo(BigDecimal number, Double _double, String patternWithoutDelimiter, byte[] _byte, Integer integer, Integer int32, Long int64, Float _float, String string, File binary, LocalDate date, LocalDateTime dateTime, String password, String paramCallback) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'number' is set
     if (number == null) {
       throw new ApiException(400, "Missing the required parameter 'number' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_double' is set
     if (_double == null) {
       throw new ApiException(400, "Missing the required parameter '_double' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter 'patternWithoutDelimiter' is set
     if (patternWithoutDelimiter == null) {
       throw new ApiException(400, "Missing the required parameter 'patternWithoutDelimiter' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_byte' is set
     if (_byte == null) {
       throw new ApiException(400, "Missing the required parameter '_byte' when calling testEndpointParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (integer != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (integer != null)
       localVarFormParams.put("integer", integer);
-if (int32 != null)
+    }
+    if (int32 != null) {
       localVarFormParams.put("int32", int32);
-if (int64 != null)
+    }
+    if (int64 != null) {
       localVarFormParams.put("int64", int64);
-if (number != null)
+    }
-      localVarFormParams.put("number", number);
+    localVarFormParams.put("number", number);
-if (_float != null)
+    if (_float != null) {
       localVarFormParams.put("float", _float);
-if (_double != null)
+    }
-      localVarFormParams.put("double", _double);
+    localVarFormParams.put("double", _double);
-if (string != null)
+    if (string != null) {
       localVarFormParams.put("string", string);
-if (patternWithoutDelimiter != null)
+    }
-      localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
+    localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
-if (_byte != null)
+    localVarFormParams.put("byte", _byte);
-      localVarFormParams.put("byte", _byte);
+    if (binary != null) {
-if (binary != null)
       localVarFormParams.put("binary", binary);
-if (date != null)
+    }
+    if (date != null) {
       localVarFormParams.put("date", date);
-if (dateTime != null)
+    }
+    if (dateTime != null) {
       localVarFormParams.put("dateTime", dateTime);
-if (password != null)
+    }
+    if (password != null) {
       localVarFormParams.put("password", password);
-if (paramCallback != null)
+    }
+    if (paramCallback != null) {
       localVarFormParams.put("callback", paramCallback);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"http_basic_test"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("FakeApi.testEndpointParameters", "/fake", "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "http_basic_test" };
-
-    return apiClient.invokeAPI("FakeApi.testEndpointParameters", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -747,104 +524,71 @@ if (paramCallback != null)
      </table>
    */
   public ApiResponse<Void> testEnumParametersWithHttpInfo(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
-    Object localVarPostBody = null;
+    // Query parameters
-    
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    // create path and map variables
+            apiClient.parameterToPairs("csv", "enum_query_string_array", enumQueryStringArray)
-    String localVarPath = "/fake";
+    );
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "enum_query_string_array", enumQueryStringArray));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_string", enumQueryString));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_integer", enumQueryInteger));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_double", enumQueryDouble));
 
-    if (enumHeaderStringArray != null)
+    // Header parameters
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
+    if (enumHeaderStringArray != null) {
       localVarHeaderParams.put("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
-if (enumHeaderString != null)
+    }
+    if (enumHeaderString != null) {
       localVarHeaderParams.put("enum_header_string", apiClient.parameterToString(enumHeaderString));
+    }
 
-    
+    // Form parameters
-    if (enumFormStringArray != null)
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
+    if (enumFormStringArray != null) {
       localVarFormParams.put("enum_form_string_array", enumFormStringArray);
-if (enumFormString != null)
+    }
+    if (enumFormString != null) {
       localVarFormParams.put("enum_form_string", enumFormString);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    return apiClient.invokeAPI("FakeApi.testEnumParameters", "/fake", "GET", localVarQueryParams, null,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+                               localVarHeaderParams, new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-
+                               null, null, false);
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testEnumParameters", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 
 private ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'requiredStringGroup' is set
     if (requiredStringGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredStringGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredBooleanGroup' is set
     if (requiredBooleanGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredBooleanGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredInt64Group' is set
     if (requiredInt64Group == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredInt64Group' when calling testGroupParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "required_string_group", requiredStringGroup)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_string_group", requiredStringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_int64_group", requiredInt64Group));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "string_group", stringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "int64_group", int64Group));
 
-    if (requiredBooleanGroup != null)
+    // Header parameters
-      localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-if (booleanGroup != null)
+    localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    if (booleanGroup != null) {
       localVarHeaderParams.put("boolean_group", apiClient.parameterToString(booleanGroup));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    return apiClient.invokeAPI("FakeApi.testGroupParameters", "/fake", "DELETE", localVarQueryParams, null,
-      
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    };
+                               null, null, false);
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testGroupParameters", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 
   public class APItestGroupParametersRequest {
@@ -989,41 +733,16 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testInlineAdditionalPropertiesWithHttpInfo(Map<String, String> param) throws ApiException {
-    Object localVarPostBody = param;
+    // Check required parameters
-    
-    // verify the required parameter 'param' is set
     if (param == null) {
       throw new ApiException(400, "Missing the required parameter 'param' when calling testInlineAdditionalProperties");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/inline-additionalProperties";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", "/fake/inline-additionalProperties", "POST", new ArrayList<>(), param,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * test json serialization of form data
@@ -1055,50 +774,24 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testJsonFormDataWithHttpInfo(String param, String param2) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'param' is set
     if (param == null) {
       throw new ApiException(400, "Missing the required parameter 'param' when calling testJsonFormData");
     }
-    
-    // verify the required parameter 'param2' is set
     if (param2 == null) {
       throw new ApiException(400, "Missing the required parameter 'param2' when calling testJsonFormData");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/jsonFormData";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    localVarFormParams.put("param", param);
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    localVarFormParams.put("param2", param2);
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    
+    return apiClient.invokeAPI("FakeApi.testJsonFormData", "/fake/jsonFormData", "GET", new ArrayList<>(), null,
-    if (param != null)
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-      localVarFormParams.put("param", param);
+                               null, null, false);
-if (param2 != null)
-      localVarFormParams.put("param2", param2);
-
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testJsonFormData", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -1136,65 +829,36 @@ if (param2 != null)
      </table>
    */
   public ApiResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'pipe' is set
     if (pipe == null) {
       throw new ApiException(400, "Missing the required parameter 'pipe' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'ioutil' is set
     if (ioutil == null) {
       throw new ApiException(400, "Missing the required parameter 'ioutil' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'http' is set
     if (http == null) {
       throw new ApiException(400, "Missing the required parameter 'http' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'url' is set
     if (url == null) {
       throw new ApiException(400, "Missing the required parameter 'url' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'context' is set
     if (context == null) {
       throw new ApiException(400, "Missing the required parameter 'context' when calling testQueryParameterCollectionFormat");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/test-query-parameters";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "pipe", pipe)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "pipe", pipe));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "ioutil", ioutil));
     localVarQueryParams.addAll(apiClient.parameterToPairs("ssv", "http", http));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "url", url));
     localVarQueryParams.addAll(apiClient.parameterToPairs("multi", "context", context));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
+    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", "/fake/test-query-parameters", "PUT", localVarQueryParams, null,
-    final String[] localVarAccepts = {
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-      
+                               null, null, false);
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,17 @@ public class FakeClassnameTags123Api {
      </table>
    */
   public ApiResponse<Client> testClassnameWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testClassname");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake_classname_test";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key_query" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
+    String[] localVarAuthNames = new String[] {"api_key_query"};
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", "/fake_classname_test", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/PetApi.java

@@ -15,6 +15,7 @@ import java.util.Set;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -78,40 +79,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> addPetWithHttpInfo(Pet body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling addPet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.addPet", "/pet", "POST", new ArrayList<>(), body,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.addPet", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -146,43 +123,26 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> deletePetWithHttpInfo(Long petId, String apiKey) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling deletePet");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Header parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (apiKey != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    if (apiKey != null)
       localVarHeaderParams.put("api_key", apiClient.parameterToString(apiKey));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-      
+    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", new ArrayList<>(), null,
-    };
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -216,43 +176,22 @@ public class PetApi {
      </table>
    */
   public ApiResponse<List<Pet>> findPetsByStatusWithHttpInfo(List<String> status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'status' is set
     if (status == null) {
       throw new ApiException(400, "Missing the required parameter 'status' when calling findPetsByStatus");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByStatus";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "status", status)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "status", status));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByStatus", "/pet/findByStatus", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByStatus", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -290,43 +229,22 @@ public class PetApi {
    */
   @Deprecated
   public ApiResponse<Set<Pet>> findPetsByTagsWithHttpInfo(Set<String> tags) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'tags' is set
     if (tags == null) {
       throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByTags";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "tags", tags)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "tags", tags));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<Set<Pet>> localVarReturnType = new GenericType<Set<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByTags", "/pet/findByTags", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByTags", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -362,43 +280,21 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Pet> getPetByIdWithHttpInfo(Long petId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling getPetById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"api_key"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -435,40 +331,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithHttpInfo(Pet body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling updatePet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.updatePet", "/pet", "PUT", new ArrayList<>(), body,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePet", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -503,45 +375,29 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithFormWithHttpInfo(Long petId, String name, String status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling updatePetWithForm");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (name != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (name != null)
       localVarFormParams.put("name", name);
-if (status != null)
+    }
+    if (status != null) {
       localVarFormParams.put("status", status);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -577,47 +433,30 @@ if (status != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithHttpInfo(Long petId, String additionalMetadata, File _file) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}/uploadImage"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (_file != null)
+    }
+    if (_file != null) {
       localVarFormParams.put("file", _file);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-      "application/json"
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -653,52 +492,31 @@ if (_file != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithRequiredFileWithHttpInfo(Long petId, File requiredFile, String additionalMetadata) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFileWithRequiredFile");
     }
-    
-    // verify the required parameter 'requiredFile' is set
     if (requiredFile == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredFile' when calling uploadFileWithRequiredFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/fake/{petId}/uploadImageWithRequiredFile"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (requiredFile != null)
+    }
-      localVarFormParams.put("requiredFile", requiredFile);
+    localVarFormParams.put("requiredFile", requiredFile);
-
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Order;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -75,42 +76,20 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Void> deleteOrderWithHttpInfo(String orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling deleteOrder");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Returns pet inventories by status
@@ -139,37 +118,12 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Map<String, Integer>> getInventoryWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/store/inventory";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
     GenericType<Map<String, Integer>> localVarReturnType = new GenericType<Map<String, Integer>>() {};
-
+    return apiClient.invokeAPI("StoreApi.getInventory", "/store/inventory", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getInventory", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -205,44 +159,21 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> getOrderByIdWithHttpInfo(Long orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Place an order for a pet
@@ -275,42 +206,16 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> placeOrderWithHttpInfo(Order body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling placeOrder");
     }
-    
-    // create path and map variables
-    String localVarPath = "/store/order";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.placeOrder", "/store/order", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("StoreApi.placeOrder", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/api/UserApi.java

@@ -13,6 +13,7 @@ import org.openapitools.client.model.User;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,41 +75,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUserWithHttpInfo(User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUser", "/user", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUser", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -138,41 +114,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithArrayInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithArray";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", "/user/createWithArray", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -202,41 +153,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithListInputWithHttpInfo(List<User> body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithListInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithList";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithListInput", "/user/createWithList", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithListInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Delete user
@@ -268,42 +194,20 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> deleteUserWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling deleteUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Get user by user name
@@ -338,44 +242,21 @@ public class UserApi {
      </table>
    */
   public ApiResponse<User> getUserByNameWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling getUserByName");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<User> localVarReturnType = new GenericType<User>() {};
-
+    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs user into the system
@@ -410,50 +291,26 @@ public class UserApi {
      </table>
    */
   public ApiResponse<String> loginUserWithHttpInfo(String username, String password) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling loginUser");
     }
-    
-    // verify the required parameter 'password' is set
     if (password == null) {
       throw new ApiException(400, "Missing the required parameter 'password' when calling loginUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/login";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "username", username)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "username", username));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "password", password));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("UserApi.loginUser", "/user/login", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("UserApi.loginUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs out current logged in user session
@@ -481,36 +338,11 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> logoutUserWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    return apiClient.invokeAPI("UserApi.logoutUser", "/user/logout", "GET", new ArrayList<>(), null,
-    String localVarPath = "/user/logout";
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
+                               null, null, false);
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.logoutUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Updated user
@@ -544,46 +376,22 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> updateUserWithHttpInfo(String username, User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling updateUser");
     }
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling updateUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesAnyType {
   @JsonAnySetter
   public AdditionalPropertiesAnyType putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesArray {
   @JsonAnySetter
   public AdditionalPropertiesArray putAdditionalProperty(String key, List value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, List>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesBoolean {
   @JsonAnySetter
   public AdditionalPropertiesBoolean putAdditionalProperty(String key, Boolean value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Boolean>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesInteger {
   @JsonAnySetter
   public AdditionalPropertiesInteger putAdditionalProperty(String key, Integer value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Integer>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesNumber {
   @JsonAnySetter
   public AdditionalPropertiesNumber putAdditionalProperty(String key, BigDecimal value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, BigDecimal>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesObject {
   @JsonAnySetter
   public AdditionalPropertiesObject putAdditionalProperty(String key, Map value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Map>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesString {
   @JsonAnySetter
   public AdditionalPropertiesString putAdditionalProperty(String key, String value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, String>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Animal.java

@@ -153,14 +153,14 @@ public class Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  mappings.put("Animal", Animal.class);
+    mappings.put("Animal", Animal.class);
-  JSON.registerDiscriminator(Animal.class, "className", mappings);
+    JSON.registerDiscriminator(Animal.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/BigCat.java

@@ -156,11 +156,11 @@ public class BigCat extends Cat {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  JSON.registerDiscriminator(BigCat.class, "className", mappings);
+    JSON.registerDiscriminator(BigCat.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Cat.java

@@ -121,12 +121,12 @@ public class Cat extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  JSON.registerDiscriminator(Cat.class, "className", mappings);
+    JSON.registerDiscriminator(Cat.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Dog.java

@@ -117,11 +117,11 @@ public class Dog extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  JSON.registerDiscriminator(Dog.class, "className", mappings);
+    JSON.registerDiscriminator(Dog.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/ApiClient.java

@@ -36,6 +36,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -43,11 +44,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -70,25 +74,26 @@ import org.openapitools.client.auth.OAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io:80/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://petstore.swagger.io:80/v2",
+                  "http://petstore.swagger.io:80/v2",
-      "No description provided",
+                  "No description provided",
-      new HashMap<String, ServerVariable>()
+                  new LinkedHashMap<>()
-    )
+          )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-  }};
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -125,7 +130,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("petstore_auth");
@@ -163,7 +168,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -751,7 +756,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -810,14 +815,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -829,8 +833,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -850,8 +854,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1143,15 +1147,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        null,
+          cookieParams,
-        method,
+          null,
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1168,7 +1174,7 @@ public class ApiClient extends JavaTimeFormatter {
       final int statusCode = response.getStatusInfo().getStatusCode();
 
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1339,10 +1345,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/JSON.java

@@ -64,7 +64,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -84,7 +84,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -193,12 +193,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,16 @@ public class AnotherFakeApi {
      </table>
    */
   public ApiResponse<Client> call123testSpecialTagsWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling call123testSpecialTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/another-fake/dummy";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", "/another-fake/dummy", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -20,6 +20,7 @@ import org.openapitools.client.model.XmlItem;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -81,41 +82,16 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> createXmlItemWithHttpInfo(XmlItem xmlItem) throws ApiException {
-    Object localVarPostBody = xmlItem;
+    // Check required parameters
-    
-    // verify the required parameter 'xmlItem' is set
     if (xmlItem == null) {
       throw new ApiException(400, "Missing the required parameter 'xmlItem' when calling createXmlItem");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/create_xml_item";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/xml", "application/xml; charset=utf-8", "application/xml; charset=utf-16", "text/xml", "text/xml; charset=utf-8", "text/xml; charset=utf-16");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.createXmlItem", "/fake/create_xml_item", "POST", new ArrayList<>(), xmlItem,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/xml", "application/xml; charset=utf-8", "application/xml; charset=utf-16", "text/xml", "text/xml; charset=utf-8", "text/xml; charset=utf-16"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.createXmlItem", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -146,38 +122,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Boolean> fakeOuterBooleanSerializeWithHttpInfo(Boolean body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/boolean";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<Boolean> localVarReturnType = new GenericType<Boolean>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", "/fake/outer/boolean", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -208,38 +158,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<OuterComposite> fakeOuterCompositeSerializeWithHttpInfo(OuterComposite body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/composite";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<OuterComposite> localVarReturnType = new GenericType<OuterComposite>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", "/fake/outer/composite", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -270,38 +194,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<BigDecimal> fakeOuterNumberSerializeWithHttpInfo(BigDecimal body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/number";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<BigDecimal> localVarReturnType = new GenericType<BigDecimal>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", "/fake/outer/number", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -332,38 +230,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<String> fakeOuterStringSerializeWithHttpInfo(String body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/outer/string";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", "/fake/outer/string", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -393,41 +265,16 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithFileSchemaWithHttpInfo(FileSchemaTestClass body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithFileSchema");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-file-schema";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", "/fake/body-with-file-schema", "PUT", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -459,47 +306,24 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithQueryParamsWithHttpInfo(String query, User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'query' is set
     if (query == null) {
       throw new ApiException(400, "Missing the required parameter 'query' when calling testBodyWithQueryParams");
     }
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithQueryParams");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-query-params";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "query", query)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "query", query));
+    String localVarAccept = apiClient.selectHeaderAccept();
-
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    
+    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", "/fake/body-with-query-params", "PUT", localVarQueryParams, body,
-    
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    
+                               null, null, false);
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * To test \&quot;client\&quot; model
@@ -530,43 +354,17 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Client> testClientModelWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testClientModel");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeApi.testClientModel", "/fake", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.testClientModel", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
@@ -624,83 +422,62 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testEndpointParametersWithHttpInfo(BigDecimal number, Double _double, String patternWithoutDelimiter, byte[] _byte, Integer integer, Integer int32, Long int64, Float _float, String string, File binary, LocalDate date, OffsetDateTime dateTime, String password, String paramCallback) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'number' is set
     if (number == null) {
       throw new ApiException(400, "Missing the required parameter 'number' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_double' is set
     if (_double == null) {
       throw new ApiException(400, "Missing the required parameter '_double' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter 'patternWithoutDelimiter' is set
     if (patternWithoutDelimiter == null) {
       throw new ApiException(400, "Missing the required parameter 'patternWithoutDelimiter' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_byte' is set
     if (_byte == null) {
       throw new ApiException(400, "Missing the required parameter '_byte' when calling testEndpointParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (integer != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (integer != null)
       localVarFormParams.put("integer", integer);
-if (int32 != null)
+    }
+    if (int32 != null) {
       localVarFormParams.put("int32", int32);
-if (int64 != null)
+    }
+    if (int64 != null) {
       localVarFormParams.put("int64", int64);
-if (number != null)
+    }
-      localVarFormParams.put("number", number);
+    localVarFormParams.put("number", number);
-if (_float != null)
+    if (_float != null) {
       localVarFormParams.put("float", _float);
-if (_double != null)
+    }
-      localVarFormParams.put("double", _double);
+    localVarFormParams.put("double", _double);
-if (string != null)
+    if (string != null) {
       localVarFormParams.put("string", string);
-if (patternWithoutDelimiter != null)
+    }
-      localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
+    localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
-if (_byte != null)
+    localVarFormParams.put("byte", _byte);
-      localVarFormParams.put("byte", _byte);
+    if (binary != null) {
-if (binary != null)
       localVarFormParams.put("binary", binary);
-if (date != null)
+    }
+    if (date != null) {
       localVarFormParams.put("date", date);
-if (dateTime != null)
+    }
+    if (dateTime != null) {
       localVarFormParams.put("dateTime", dateTime);
-if (password != null)
+    }
+    if (password != null) {
       localVarFormParams.put("password", password);
-if (paramCallback != null)
+    }
+    if (paramCallback != null) {
       localVarFormParams.put("callback", paramCallback);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"http_basic_test"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("FakeApi.testEndpointParameters", "/fake", "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "http_basic_test" };
-
-    return apiClient.invokeAPI("FakeApi.testEndpointParameters", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -747,104 +524,71 @@ if (paramCallback != null)
      </table>
    */
   public ApiResponse<Void> testEnumParametersWithHttpInfo(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
-    Object localVarPostBody = null;
+    // Query parameters
-    
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    // create path and map variables
+            apiClient.parameterToPairs("csv", "enum_query_string_array", enumQueryStringArray)
-    String localVarPath = "/fake";
+    );
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "enum_query_string_array", enumQueryStringArray));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_string", enumQueryString));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_integer", enumQueryInteger));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_double", enumQueryDouble));
 
-    if (enumHeaderStringArray != null)
+    // Header parameters
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
+    if (enumHeaderStringArray != null) {
       localVarHeaderParams.put("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
-if (enumHeaderString != null)
+    }
+    if (enumHeaderString != null) {
       localVarHeaderParams.put("enum_header_string", apiClient.parameterToString(enumHeaderString));
+    }
 
-    
+    // Form parameters
-    if (enumFormStringArray != null)
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
+    if (enumFormStringArray != null) {
       localVarFormParams.put("enum_form_string_array", enumFormStringArray);
-if (enumFormString != null)
+    }
+    if (enumFormString != null) {
       localVarFormParams.put("enum_form_string", enumFormString);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    return apiClient.invokeAPI("FakeApi.testEnumParameters", "/fake", "GET", localVarQueryParams, null,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+                               localVarHeaderParams, new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-
+                               null, null, false);
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testEnumParameters", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 
 private ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'requiredStringGroup' is set
     if (requiredStringGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredStringGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredBooleanGroup' is set
     if (requiredBooleanGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredBooleanGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredInt64Group' is set
     if (requiredInt64Group == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredInt64Group' when calling testGroupParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "required_string_group", requiredStringGroup)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_string_group", requiredStringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_int64_group", requiredInt64Group));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "string_group", stringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "int64_group", int64Group));
 
-    if (requiredBooleanGroup != null)
+    // Header parameters
-      localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-if (booleanGroup != null)
+    localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    if (booleanGroup != null) {
       localVarHeaderParams.put("boolean_group", apiClient.parameterToString(booleanGroup));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    return apiClient.invokeAPI("FakeApi.testGroupParameters", "/fake", "DELETE", localVarQueryParams, null,
-      
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    };
+                               null, null, false);
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testGroupParameters", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 
   public class APItestGroupParametersRequest {
@@ -989,41 +733,16 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testInlineAdditionalPropertiesWithHttpInfo(Map<String, String> param) throws ApiException {
-    Object localVarPostBody = param;
+    // Check required parameters
-    
-    // verify the required parameter 'param' is set
     if (param == null) {
       throw new ApiException(400, "Missing the required parameter 'param' when calling testInlineAdditionalProperties");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/inline-additionalProperties";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", "/fake/inline-additionalProperties", "POST", new ArrayList<>(), param,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * test json serialization of form data
@@ -1055,50 +774,24 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testJsonFormDataWithHttpInfo(String param, String param2) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'param' is set
     if (param == null) {
       throw new ApiException(400, "Missing the required parameter 'param' when calling testJsonFormData");
     }
-    
-    // verify the required parameter 'param2' is set
     if (param2 == null) {
       throw new ApiException(400, "Missing the required parameter 'param2' when calling testJsonFormData");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/jsonFormData";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    localVarFormParams.put("param", param);
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    localVarFormParams.put("param2", param2);
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    
+    return apiClient.invokeAPI("FakeApi.testJsonFormData", "/fake/jsonFormData", "GET", new ArrayList<>(), null,
-    if (param != null)
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-      localVarFormParams.put("param", param);
+                               null, null, false);
-if (param2 != null)
-      localVarFormParams.put("param2", param2);
-
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testJsonFormData", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -1136,65 +829,36 @@ if (param2 != null)
      </table>
    */
   public ApiResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'pipe' is set
     if (pipe == null) {
       throw new ApiException(400, "Missing the required parameter 'pipe' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'ioutil' is set
     if (ioutil == null) {
       throw new ApiException(400, "Missing the required parameter 'ioutil' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'http' is set
     if (http == null) {
       throw new ApiException(400, "Missing the required parameter 'http' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'url' is set
     if (url == null) {
       throw new ApiException(400, "Missing the required parameter 'url' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'context' is set
     if (context == null) {
       throw new ApiException(400, "Missing the required parameter 'context' when calling testQueryParameterCollectionFormat");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/test-query-parameters";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "pipe", pipe)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "pipe", pipe));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "ioutil", ioutil));
     localVarQueryParams.addAll(apiClient.parameterToPairs("ssv", "http", http));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "url", url));
     localVarQueryParams.addAll(apiClient.parameterToPairs("multi", "context", context));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
+    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", "/fake/test-query-parameters", "PUT", localVarQueryParams, null,
-    final String[] localVarAccepts = {
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-      
+                               null, null, false);
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,17 @@ public class FakeClassnameTags123Api {
      </table>
    */
   public ApiResponse<Client> testClassnameWithHttpInfo(Client body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling testClassname");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake_classname_test";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key_query" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
+    String[] localVarAuthNames = new String[] {"api_key_query"};
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", "/fake_classname_test", "PATCH", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/PetApi.java

@@ -15,6 +15,7 @@ import java.util.Set;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -78,40 +79,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> addPetWithHttpInfo(Pet body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling addPet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.addPet", "/pet", "POST", new ArrayList<>(), body,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.addPet", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -146,43 +123,26 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> deletePetWithHttpInfo(Long petId, String apiKey) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling deletePet");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Header parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (apiKey != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    if (apiKey != null)
       localVarHeaderParams.put("api_key", apiClient.parameterToString(apiKey));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-      
+    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", new ArrayList<>(), null,
-    };
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -216,43 +176,22 @@ public class PetApi {
      </table>
    */
   public ApiResponse<List<Pet>> findPetsByStatusWithHttpInfo(List<String> status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'status' is set
     if (status == null) {
       throw new ApiException(400, "Missing the required parameter 'status' when calling findPetsByStatus");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByStatus";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "status", status)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "status", status));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByStatus", "/pet/findByStatus", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByStatus", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -290,43 +229,22 @@ public class PetApi {
    */
   @Deprecated
   public ApiResponse<Set<Pet>> findPetsByTagsWithHttpInfo(Set<String> tags) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'tags' is set
     if (tags == null) {
       throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByTags";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "tags", tags)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "tags", tags));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<Set<Pet>> localVarReturnType = new GenericType<Set<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByTags", "/pet/findByTags", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByTags", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -362,43 +280,21 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Pet> getPetByIdWithHttpInfo(Long petId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling getPetById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"api_key"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -435,40 +331,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithHttpInfo(Pet body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling updatePet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.updatePet", "/pet", "PUT", new ArrayList<>(), body,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePet", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -503,45 +375,29 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithFormWithHttpInfo(Long petId, String name, String status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling updatePetWithForm");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (name != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (name != null)
       localVarFormParams.put("name", name);
-if (status != null)
+    }
+    if (status != null) {
       localVarFormParams.put("status", status);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -577,47 +433,30 @@ if (status != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithHttpInfo(Long petId, String additionalMetadata, File _file) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}/uploadImage"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (_file != null)
+    }
+    if (_file != null) {
       localVarFormParams.put("file", _file);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-      "application/json"
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -653,52 +492,31 @@ if (_file != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithRequiredFileWithHttpInfo(Long petId, File requiredFile, String additionalMetadata) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFileWithRequiredFile");
     }
-    
-    // verify the required parameter 'requiredFile' is set
     if (requiredFile == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredFile' when calling uploadFileWithRequiredFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/fake/{petId}/uploadImageWithRequiredFile"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (requiredFile != null)
+    }
-      localVarFormParams.put("requiredFile", requiredFile);
+    localVarFormParams.put("requiredFile", requiredFile);
-
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Order;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -75,42 +76,20 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Void> deleteOrderWithHttpInfo(String orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling deleteOrder");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Returns pet inventories by status
@@ -139,37 +118,12 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Map<String, Integer>> getInventoryWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/store/inventory";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
     GenericType<Map<String, Integer>> localVarReturnType = new GenericType<Map<String, Integer>>() {};
-
+    return apiClient.invokeAPI("StoreApi.getInventory", "/store/inventory", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getInventory", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -205,44 +159,21 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> getOrderByIdWithHttpInfo(Long orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Place an order for a pet
@@ -275,42 +206,16 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> placeOrderWithHttpInfo(Order body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling placeOrder");
     }
-    
-    // create path and map variables
-    String localVarPath = "/store/order";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.placeOrder", "/store/order", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("StoreApi.placeOrder", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/api/UserApi.java

@@ -13,6 +13,7 @@ import org.openapitools.client.model.User;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,41 +75,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUserWithHttpInfo(User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUser", "/user", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUser", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -138,41 +114,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithArrayInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithArray";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", "/user/createWithArray", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -202,41 +153,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithListInputWithHttpInfo(List<User> body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithListInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithList";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithListInput", "/user/createWithList", "POST", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithListInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Delete user
@@ -268,42 +194,20 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> deleteUserWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling deleteUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Get user by user name
@@ -338,44 +242,21 @@ public class UserApi {
      </table>
    */
   public ApiResponse<User> getUserByNameWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling getUserByName");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<User> localVarReturnType = new GenericType<User>() {};
-
+    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs user into the system
@@ -410,50 +291,26 @@ public class UserApi {
      </table>
    */
   public ApiResponse<String> loginUserWithHttpInfo(String username, String password) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling loginUser");
     }
-    
-    // verify the required parameter 'password' is set
     if (password == null) {
       throw new ApiException(400, "Missing the required parameter 'password' when calling loginUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/login";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "username", username)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "username", username));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "password", password));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("UserApi.loginUser", "/user/login", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("UserApi.loginUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs out current logged in user session
@@ -481,36 +338,11 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> logoutUserWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    return apiClient.invokeAPI("UserApi.logoutUser", "/user/logout", "GET", new ArrayList<>(), null,
-    String localVarPath = "/user/logout";
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
+                               null, null, false);
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.logoutUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Updated user
@@ -544,46 +376,22 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> updateUserWithHttpInfo(String username, User body) throws ApiException {
-    Object localVarPostBody = body;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling updateUser");
     }
-    
-    // verify the required parameter 'body' is set
     if (body == null) {
       throw new ApiException(400, "Missing the required parameter 'body' when calling updateUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", new ArrayList<>(), body,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesAnyType {
   @JsonAnySetter
   public AdditionalPropertiesAnyType putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesArray {
   @JsonAnySetter
   public AdditionalPropertiesArray putAdditionalProperty(String key, List value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, List>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesBoolean {
   @JsonAnySetter
   public AdditionalPropertiesBoolean putAdditionalProperty(String key, Boolean value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Boolean>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesInteger {
   @JsonAnySetter
   public AdditionalPropertiesInteger putAdditionalProperty(String key, Integer value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Integer>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesNumber {
   @JsonAnySetter
   public AdditionalPropertiesNumber putAdditionalProperty(String key, BigDecimal value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, BigDecimal>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java

@@ -83,7 +83,7 @@ public class AdditionalPropertiesObject {
   @JsonAnySetter
   public AdditionalPropertiesObject putAdditionalProperty(String key, Map value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Map>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java

@@ -82,7 +82,7 @@ public class AdditionalPropertiesString {
   @JsonAnySetter
   public AdditionalPropertiesString putAdditionalProperty(String key, String value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, String>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Animal.java

@@ -153,14 +153,14 @@ public class Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  mappings.put("Animal", Animal.class);
+    mappings.put("Animal", Animal.class);
-  JSON.registerDiscriminator(Animal.class, "className", mappings);
+    JSON.registerDiscriminator(Animal.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/BigCat.java

@@ -156,11 +156,11 @@ public class BigCat extends Cat {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  JSON.registerDiscriminator(BigCat.class, "className", mappings);
+    JSON.registerDiscriminator(BigCat.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Cat.java

@@ -121,12 +121,12 @@ public class Cat extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("BigCat", BigCat.class);
+    mappings.put("BigCat", BigCat.class);
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  JSON.registerDiscriminator(Cat.class, "className", mappings);
+    JSON.registerDiscriminator(Cat.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Dog.java

@@ -117,11 +117,11 @@ public class Dog extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  JSON.registerDiscriminator(Dog.class, "className", mappings);
+    JSON.registerDiscriminator(Dog.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/ApiClient.java

@@ -36,6 +36,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -43,11 +44,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -71,94 +75,93 @@ import org.openapitools.client.auth.OAuth;
  */
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io:80/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://{server}.swagger.io:{port}/v2",
+                  "http://{server}.swagger.io:{port}/v2",
-      "petstore server",
+                  "petstore server",
-      new HashMap<String, ServerVariable>() {{
+                  Stream.<Entry<String, ServerVariable>>of(
-        put("server", new ServerVariable(
+                          new SimpleEntry<>("server", new ServerVariable(
-          "No description provided",
+                                  "No description provided",
-          "petstore",
+                                  "petstore",
-          new HashSet<String>(
+                                  new LinkedHashSet<>(Arrays.asList(
-            Arrays.asList(
+                                          "petstore",
-              "petstore",
+                                          "qa-petstore",
-              "qa-petstore",
+                                          "dev-petstore"
-              "dev-petstore"
+                                  ))
-            )
+                          )),
+                          new SimpleEntry<>("port", new ServerVariable(
+                                  "No description provided",
+                                  "80",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "80",
+                                          "8080"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
+          ),
+          new ServerConfiguration(
+                  "https://localhost:8080/{version}",
+                  "The local server",
+                  Stream.<Entry<String, ServerVariable>>of(
+                          new SimpleEntry<>("version", new ServerVariable(
+                                  "No description provided",
+                                  "v2",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "v1",
+                                          "v2"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
+          ),
+          new ServerConfiguration(
+                  "https://127.0.0.1/no_variable",
+                  "The local server without variables",
+                  new LinkedHashMap<>()
           )
-        ));
-        put("port", new ServerVariable(
-          "No description provided",
-          "80",
-          new HashSet<String>(
-            Arrays.asList(
-              "80",
-              "8080"
-            )
-          )
-        ));
-      }}
-    ),
-    new ServerConfiguration(
-      "https://localhost:8080/{version}",
-      "The local server",
-      new HashMap<String, ServerVariable>() {{
-        put("version", new ServerVariable(
-          "No description provided",
-          "v2",
-          new HashSet<String>(
-            Arrays.asList(
-              "v1",
-              "v2"
-            )
-          )
-        ));
-      }}
-    ),
-    new ServerConfiguration(
-      "https://127.0.0.1/no_variable",
-      "The local server without variables",
-      new HashMap<String, ServerVariable>()
-    )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers;
-    put("PetApi.addPet", new ArrayList<ServerConfiguration>(Arrays.asList(
-      new ServerConfiguration(
-        "http://petstore.swagger.io/v2",
-        "No description provided",
-        new HashMap<String, ServerVariable>()
-      ),
 
-      new ServerConfiguration(
+  {
-        "http://path-server-test.petstore.local/v2",
+    Map<String, List<ServerConfiguration>> operationServers = new LinkedHashMap<>();
-        "No description provided",
+    operationServers.put("PetApi.addPet", new ArrayList<>(Arrays.asList(
-        new HashMap<String, ServerVariable>()
+            new ServerConfiguration(
-      )
+                    "http://petstore.swagger.io/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            ),
+            new ServerConfiguration(
+                    "http://path-server-test.petstore.local/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            )
     )));
-    put("PetApi.updatePet", new ArrayList<ServerConfiguration>(Arrays.asList(
+    operationServers.put("PetApi.updatePet", new ArrayList<>(Arrays.asList(
-      new ServerConfiguration(
+            new ServerConfiguration(
-        "http://petstore.swagger.io/v2",
+                    "http://petstore.swagger.io/v2",
-        "No description provided",
+                    "No description provided",
-        new HashMap<String, ServerVariable>()
+                    new LinkedHashMap<>()
-      ),
+            ),
+            new ServerConfiguration(
+                    "http://path-server-test.petstore.local/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            )
+    )));
+    this.operationServers = operationServers;
+  }
 
-      new ServerConfiguration(
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-        "http://path-server-test.petstore.local/v2",
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-        "No description provided",
-        new HashMap<String, ServerVariable>()
-      )
-    )));
-  }};
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -195,7 +198,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("petstore_auth");
@@ -247,7 +250,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -835,7 +838,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -894,14 +897,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -913,8 +915,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -934,8 +936,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1227,15 +1229,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        serializeToString(body, formParams, contentType, isBodyNullable),
+          cookieParams,
-        method,
+          serializeToString(body, formParams, contentType, isBodyNullable),
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1252,7 +1256,7 @@ public class ApiClient extends JavaTimeFormatter {
       final int statusCode = response.getStatusInfo().getStatusCode();
 
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1423,10 +1427,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/JSON.java

@@ -64,7 +64,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -84,7 +84,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -193,12 +193,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,16 @@ public class AnotherFakeApi {
      </table>
    */
   public ApiResponse<Client> call123testSpecialTagsWithHttpInfo(Client client) throws ApiException {
-    Object localVarPostBody = client;
+    // Check required parameters
-    
-    // verify the required parameter 'client' is set
     if (client == null) {
       throw new ApiException(400, "Missing the required parameter 'client' when calling call123testSpecialTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/another-fake/dummy";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", "/another-fake/dummy", "PATCH", new ArrayList<>(), client,
-    return apiClient.invokeAPI("AnotherFakeApi.call123testSpecialTags", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/DefaultApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.FooGetDefaultResponse;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -72,37 +73,11 @@ public class DefaultApi {
      </table>
    */
   public ApiResponse<FooGetDefaultResponse> fooGetWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/foo";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<FooGetDefaultResponse> localVarReturnType = new GenericType<FooGetDefaultResponse>() {};
-
+    return apiClient.invokeAPI("DefaultApi.fooGet", "/foo", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("DefaultApi.fooGet", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -21,6 +21,7 @@ import org.openapitools.client.model.User;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -81,38 +82,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<HealthCheckResult> fakeHealthGetWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/health";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<HealthCheckResult> localVarReturnType = new GenericType<HealthCheckResult>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeHealthGet", "/fake/health", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("FakeApi.fakeHealthGet", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -143,38 +118,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Boolean> fakeOuterBooleanSerializeWithHttpInfo(Boolean body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    // create path and map variables
-    String localVarPath = "/fake/outer/boolean";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<Boolean> localVarReturnType = new GenericType<Boolean>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", "/fake/outer/boolean", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterBooleanSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -205,38 +154,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<OuterComposite> fakeOuterCompositeSerializeWithHttpInfo(OuterComposite outerComposite) throws ApiException {
-    Object localVarPostBody = outerComposite;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    // create path and map variables
-    String localVarPath = "/fake/outer/composite";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<OuterComposite> localVarReturnType = new GenericType<OuterComposite>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", "/fake/outer/composite", "POST", new ArrayList<>(), outerComposite,
-    return apiClient.invokeAPI("FakeApi.fakeOuterCompositeSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -267,38 +190,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<BigDecimal> fakeOuterNumberSerializeWithHttpInfo(BigDecimal body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    // create path and map variables
-    String localVarPath = "/fake/outer/number";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<BigDecimal> localVarReturnType = new GenericType<BigDecimal>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", "/fake/outer/number", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterNumberSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -329,38 +226,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<String> fakeOuterStringSerializeWithHttpInfo(String body) throws ApiException {
-    Object localVarPostBody = body;
+    String localVarAccept = apiClient.selectHeaderAccept("*/*");
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    // create path and map variables
-    String localVarPath = "/fake/outer/string";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "*/*"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", "/fake/outer/string", "POST", new ArrayList<>(), body,
-    return apiClient.invokeAPI("FakeApi.fakeOuterStringSerialize", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Array of Enums
@@ -389,38 +260,12 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<List<OuterEnum>> getArrayOfEnumsWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
-    String localVarPath = "/fake/array-of-enums";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<List<OuterEnum>> localVarReturnType = new GenericType<List<OuterEnum>>() {};
-
+    return apiClient.invokeAPI("FakeApi.getArrayOfEnums", "/fake/array-of-enums", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("FakeApi.getArrayOfEnums", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * 
@@ -450,41 +295,16 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithFileSchemaWithHttpInfo(FileSchemaTestClass fileSchemaTestClass) throws ApiException {
-    Object localVarPostBody = fileSchemaTestClass;
+    // Check required parameters
-    
-    // verify the required parameter 'fileSchemaTestClass' is set
     if (fileSchemaTestClass == null) {
       throw new ApiException(400, "Missing the required parameter 'fileSchemaTestClass' when calling testBodyWithFileSchema");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-file-schema";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", "/fake/body-with-file-schema", "PUT", new ArrayList<>(), fileSchemaTestClass,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithFileSchema", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -516,47 +336,24 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testBodyWithQueryParamsWithHttpInfo(String query, User user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'query' is set
     if (query == null) {
       throw new ApiException(400, "Missing the required parameter 'query' when calling testBodyWithQueryParams");
     }
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling testBodyWithQueryParams");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/body-with-query-params";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "query", query)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "query", query));
+    String localVarAccept = apiClient.selectHeaderAccept();
-
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    
+    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", "/fake/body-with-query-params", "PUT", localVarQueryParams, user,
-    
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    
+                               null, null, false);
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testBodyWithQueryParams", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * To test \&quot;client\&quot; model
@@ -587,43 +384,17 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Client> testClientModelWithHttpInfo(Client client) throws ApiException {
-    Object localVarPostBody = client;
+    // Check required parameters
-    
-    // verify the required parameter 'client' is set
     if (client == null) {
       throw new ApiException(400, "Missing the required parameter 'client' when calling testClientModel");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeApi.testClientModel", "/fake", "PATCH", new ArrayList<>(), client,
-    return apiClient.invokeAPI("FakeApi.testClientModel", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
@@ -681,83 +452,62 @@ public class FakeApi {
      </table>
    */
   public ApiResponse<Void> testEndpointParametersWithHttpInfo(BigDecimal number, Double _double, String patternWithoutDelimiter, byte[] _byte, Integer integer, Integer int32, Long int64, Float _float, String string, File binary, LocalDate date, OffsetDateTime dateTime, String password, String paramCallback) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'number' is set
     if (number == null) {
       throw new ApiException(400, "Missing the required parameter 'number' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_double' is set
     if (_double == null) {
       throw new ApiException(400, "Missing the required parameter '_double' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter 'patternWithoutDelimiter' is set
     if (patternWithoutDelimiter == null) {
       throw new ApiException(400, "Missing the required parameter 'patternWithoutDelimiter' when calling testEndpointParameters");
     }
-    
-    // verify the required parameter '_byte' is set
     if (_byte == null) {
       throw new ApiException(400, "Missing the required parameter '_byte' when calling testEndpointParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (integer != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (integer != null)
       localVarFormParams.put("integer", integer);
-if (int32 != null)
+    }
+    if (int32 != null) {
       localVarFormParams.put("int32", int32);
-if (int64 != null)
+    }
+    if (int64 != null) {
       localVarFormParams.put("int64", int64);
-if (number != null)
+    }
-      localVarFormParams.put("number", number);
+    localVarFormParams.put("number", number);
-if (_float != null)
+    if (_float != null) {
       localVarFormParams.put("float", _float);
-if (_double != null)
+    }
-      localVarFormParams.put("double", _double);
+    localVarFormParams.put("double", _double);
-if (string != null)
+    if (string != null) {
       localVarFormParams.put("string", string);
-if (patternWithoutDelimiter != null)
+    }
-      localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
+    localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
-if (_byte != null)
+    localVarFormParams.put("byte", _byte);
-      localVarFormParams.put("byte", _byte);
+    if (binary != null) {
-if (binary != null)
       localVarFormParams.put("binary", binary);
-if (date != null)
+    }
+    if (date != null) {
       localVarFormParams.put("date", date);
-if (dateTime != null)
+    }
+    if (dateTime != null) {
       localVarFormParams.put("dateTime", dateTime);
-if (password != null)
+    }
+    if (password != null) {
       localVarFormParams.put("password", password);
-if (paramCallback != null)
+    }
+    if (paramCallback != null) {
       localVarFormParams.put("callback", paramCallback);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"http_basic_test"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("FakeApi.testEndpointParameters", "/fake", "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "http_basic_test" };
-
-    return apiClient.invokeAPI("FakeApi.testEndpointParameters", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -804,103 +554,71 @@ if (paramCallback != null)
      </table>
    */
   public ApiResponse<Void> testEnumParametersWithHttpInfo(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
-    Object localVarPostBody = null;
+    // Query parameters
-    
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    // create path and map variables
+            apiClient.parameterToPairs("multi", "enum_query_string_array", enumQueryStringArray)
-    String localVarPath = "/fake";
+    );
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("multi", "enum_query_string_array", enumQueryStringArray));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_string", enumQueryString));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_integer", enumQueryInteger));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "enum_query_double", enumQueryDouble));
 
-    if (enumHeaderStringArray != null)
+    // Header parameters
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
+    if (enumHeaderStringArray != null) {
       localVarHeaderParams.put("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
-if (enumHeaderString != null)
+    }
+    if (enumHeaderString != null) {
       localVarHeaderParams.put("enum_header_string", apiClient.parameterToString(enumHeaderString));
+    }
 
-    
+    // Form parameters
-    if (enumFormStringArray != null)
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
+    if (enumFormStringArray != null) {
       localVarFormParams.put("enum_form_string_array", enumFormStringArray);
-if (enumFormString != null)
+    }
+    if (enumFormString != null) {
       localVarFormParams.put("enum_form_string", enumFormString);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    return apiClient.invokeAPI("FakeApi.testEnumParameters", "/fake", "GET", localVarQueryParams, null,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+                               localVarHeaderParams, new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-
+                               null, null, false);
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testEnumParameters", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 
 private ApiResponse<Void> testGroupParametersWithHttpInfo(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'requiredStringGroup' is set
     if (requiredStringGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredStringGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredBooleanGroup' is set
     if (requiredBooleanGroup == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredBooleanGroup' when calling testGroupParameters");
     }
-    
-    // verify the required parameter 'requiredInt64Group' is set
     if (requiredInt64Group == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredInt64Group' when calling testGroupParameters");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "required_string_group", requiredStringGroup)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_string_group", requiredStringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "required_int64_group", requiredInt64Group));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "string_group", stringGroup));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "int64_group", int64Group));
 
-    if (requiredBooleanGroup != null)
+    // Header parameters
-      localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-if (booleanGroup != null)
+    localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+    if (booleanGroup != null) {
       localVarHeaderParams.put("boolean_group", apiClient.parameterToString(booleanGroup));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    String[] localVarAuthNames = new String[] {"bearer_test"};
-      
+    return apiClient.invokeAPI("FakeApi.testGroupParameters", "/fake", "DELETE", localVarQueryParams, null,
-    };
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "bearer_test" };
-
-    return apiClient.invokeAPI("FakeApi.testGroupParameters", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
 
@@ -1046,41 +764,16 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testInlineAdditionalPropertiesWithHttpInfo(Map<String, String> requestBody) throws ApiException {
-    Object localVarPostBody = requestBody;
+    // Check required parameters
-    
-    // verify the required parameter 'requestBody' is set
     if (requestBody == null) {
       throw new ApiException(400, "Missing the required parameter 'requestBody' when calling testInlineAdditionalProperties");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/inline-additionalProperties";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", "/fake/inline-additionalProperties", "POST", new ArrayList<>(), requestBody,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testInlineAdditionalProperties", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * test json serialization of form data
@@ -1112,50 +805,24 @@ if (booleanGroup != null)
      </table>
    */
   public ApiResponse<Void> testJsonFormDataWithHttpInfo(String param, String param2) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'param' is set
     if (param == null) {
       throw new ApiException(400, "Missing the required parameter 'param' when calling testJsonFormData");
     }
-    
-    // verify the required parameter 'param2' is set
     if (param2 == null) {
       throw new ApiException(400, "Missing the required parameter 'param2' when calling testJsonFormData");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/jsonFormData";
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    localVarFormParams.put("param", param);
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    localVarFormParams.put("param2", param2);
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
 
-
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    
+    return apiClient.invokeAPI("FakeApi.testJsonFormData", "/fake/jsonFormData", "GET", new ArrayList<>(), null,
-    if (param != null)
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-      localVarFormParams.put("param", param);
+                               null, null, false);
-if (param2 != null)
-      localVarFormParams.put("param2", param2);
-
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testJsonFormData", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * 
@@ -1193,65 +860,36 @@ if (param2 != null)
      </table>
    */
   public ApiResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'pipe' is set
     if (pipe == null) {
       throw new ApiException(400, "Missing the required parameter 'pipe' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'ioutil' is set
     if (ioutil == null) {
       throw new ApiException(400, "Missing the required parameter 'ioutil' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'http' is set
     if (http == null) {
       throw new ApiException(400, "Missing the required parameter 'http' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'url' is set
     if (url == null) {
       throw new ApiException(400, "Missing the required parameter 'url' when calling testQueryParameterCollectionFormat");
     }
-    
-    // verify the required parameter 'context' is set
     if (context == null) {
       throw new ApiException(400, "Missing the required parameter 'context' when calling testQueryParameterCollectionFormat");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake/test-query-parameters";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("multi", "pipe", pipe)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("multi", "pipe", pipe));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "ioutil", ioutil));
     localVarQueryParams.addAll(apiClient.parameterToPairs("ssv", "http", http));
     localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "url", url));
     localVarQueryParams.addAll(apiClient.parameterToPairs("multi", "context", context));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
+    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", "/fake/test-query-parameters", "PUT", localVarQueryParams, null,
-    final String[] localVarAccepts = {
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-      
+                               null, null, false);
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("FakeApi.testQueryParameterCollectionFormat", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,42 +75,17 @@ public class FakeClassnameTags123Api {
      </table>
    */
   public ApiResponse<Client> testClassnameWithHttpInfo(Client client) throws ApiException {
-    Object localVarPostBody = client;
+    // Check required parameters
-    
-    // verify the required parameter 'client' is set
     if (client == null) {
       throw new ApiException(400, "Missing the required parameter 'client' when calling testClassname");
     }
-    
-    // create path and map variables
-    String localVarPath = "/fake_classname_test";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key_query" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
+    String[] localVarAuthNames = new String[] {"api_key_query"};
     GenericType<Client> localVarReturnType = new GenericType<Client>() {};
-
+    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", "/fake_classname_test", "PATCH", new ArrayList<>(), client,
-    return apiClient.invokeAPI("FakeClassnameTags123Api.testClassname", localVarPath, "PATCH", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/PetApi.java

@@ -14,6 +14,7 @@ import org.openapitools.client.model.Pet;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -75,40 +76,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> addPetWithHttpInfo(Pet pet) throws ApiException {
-    Object localVarPostBody = pet;
+    // Check required parameters
-    
-    // verify the required parameter 'pet' is set
     if (pet == null) {
       throw new ApiException(400, "Missing the required parameter 'pet' when calling addPet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth", "http_signature_test"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.addPet", "/pet", "POST", new ArrayList<>(), pet,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth", "http_signature_test" };
-
-    return apiClient.invokeAPI("PetApi.addPet", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -141,43 +118,26 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> deletePetWithHttpInfo(Long petId, String apiKey) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling deletePet");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Header parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (apiKey != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    if (apiKey != null)
       localVarHeaderParams.put("api_key", apiClient.parameterToString(apiKey));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-      
+    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", new ArrayList<>(), null,
-    };
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -211,43 +171,22 @@ public class PetApi {
      </table>
    */
   public ApiResponse<List<Pet>> findPetsByStatusWithHttpInfo(List<String> status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'status' is set
     if (status == null) {
       throw new ApiException(400, "Missing the required parameter 'status' when calling findPetsByStatus");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByStatus";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "status", status)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "status", status));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth", "http_signature_test" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth", "http_signature_test"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByStatus", "/pet/findByStatus", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByStatus", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -285,43 +224,22 @@ public class PetApi {
    */
   @Deprecated
   public ApiResponse<List<Pet>> findPetsByTagsWithHttpInfo(List<String> tags) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'tags' is set
     if (tags == null) {
       throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByTags";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "tags", tags)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "tags", tags));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth", "http_signature_test" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth", "http_signature_test"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByTags", "/pet/findByTags", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByTags", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -357,43 +275,21 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Pet> getPetByIdWithHttpInfo(Long petId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling getPetById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"api_key"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -428,40 +324,16 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithHttpInfo(Pet pet) throws ApiException {
-    Object localVarPostBody = pet;
+    // Check required parameters
-    
-    // verify the required parameter 'pet' is set
     if (pet == null) {
       throw new ApiException(400, "Missing the required parameter 'pet' when calling updatePet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"petstore_auth", "http_signature_test"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("PetApi.updatePet", "/pet", "PUT", new ArrayList<>(), pet,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth", "http_signature_test" };
-
-    return apiClient.invokeAPI("PetApi.updatePet", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -496,45 +368,29 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithFormWithHttpInfo(Long petId, String name, String status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling updatePetWithForm");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (name != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (name != null)
       localVarFormParams.put("name", name);
-if (status != null)
+    }
+    if (status != null) {
       localVarFormParams.put("status", status);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -570,47 +426,30 @@ if (status != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithHttpInfo(Long petId, String additionalMetadata, File _file) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}/uploadImage"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (_file != null)
+    }
+    if (_file != null) {
       localVarFormParams.put("file", _file);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-      "application/json"
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -646,52 +485,31 @@ if (_file != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithRequiredFileWithHttpInfo(Long petId, File requiredFile, String additionalMetadata) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFileWithRequiredFile");
     }
-    
-    // verify the required parameter 'requiredFile' is set
     if (requiredFile == null) {
       throw new ApiException(400, "Missing the required parameter 'requiredFile' when calling uploadFileWithRequiredFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/fake/{petId}/uploadImageWithRequiredFile"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (requiredFile != null)
+    }
-      localVarFormParams.put("requiredFile", requiredFile);
+    localVarFormParams.put("requiredFile", requiredFile);
-
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFileWithRequiredFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Order;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -75,42 +76,20 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Void> deleteOrderWithHttpInfo(String orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling deleteOrder");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Returns pet inventories by status
@@ -139,37 +118,12 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Map<String, Integer>> getInventoryWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/store/inventory";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
     GenericType<Map<String, Integer>> localVarReturnType = new GenericType<Map<String, Integer>>() {};
-
+    return apiClient.invokeAPI("StoreApi.getInventory", "/store/inventory", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getInventory", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -205,44 +159,21 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> getOrderByIdWithHttpInfo(Long orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{order_id}"
-      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{order_id}", apiClient.escapeString(orderId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Place an order for a pet
@@ -275,42 +206,16 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> placeOrderWithHttpInfo(Order order) throws ApiException {
-    Object localVarPostBody = order;
+    // Check required parameters
-    
-    // verify the required parameter 'order' is set
     if (order == null) {
       throw new ApiException(400, "Missing the required parameter 'order' when calling placeOrder");
     }
-    
-    // create path and map variables
-    String localVarPath = "/store/order";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.placeOrder", "/store/order", "POST", new ArrayList<>(), order,
-    return apiClient.invokeAPI("StoreApi.placeOrder", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/api/UserApi.java

@@ -13,6 +13,7 @@ import org.openapitools.client.model.User;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,41 +75,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUserWithHttpInfo(User user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUser", "/user", "POST", new ArrayList<>(), user,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUser", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -138,41 +114,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUsersWithArrayInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithArray";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", "/user/createWithArray", "POST", new ArrayList<>(), user,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Creates list of users with given input array
@@ -202,41 +153,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithListInputWithHttpInfo(List<User> user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUsersWithListInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithList";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithListInput", "/user/createWithList", "POST", new ArrayList<>(), user,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithListInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Delete user
@@ -268,42 +194,20 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> deleteUserWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling deleteUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Get user by user name
@@ -338,44 +242,21 @@ public class UserApi {
      </table>
    */
   public ApiResponse<User> getUserByNameWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling getUserByName");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<User> localVarReturnType = new GenericType<User>() {};
-
+    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs user into the system
@@ -410,50 +291,26 @@ public class UserApi {
      </table>
    */
   public ApiResponse<String> loginUserWithHttpInfo(String username, String password) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling loginUser");
     }
-    
-    // verify the required parameter 'password' is set
     if (password == null) {
       throw new ApiException(400, "Missing the required parameter 'password' when calling loginUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/login";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "username", username)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "username", username));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "password", password));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("UserApi.loginUser", "/user/login", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("UserApi.loginUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs out current logged in user session
@@ -481,36 +338,11 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> logoutUserWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    return apiClient.invokeAPI("UserApi.logoutUser", "/user/logout", "GET", new ArrayList<>(), null,
-    String localVarPath = "/user/logout";
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
+                               null, null, false);
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.logoutUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Updated user
@@ -544,46 +376,22 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> updateUserWithHttpInfo(String username, User user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling updateUser");
     }
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling updateUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", new ArrayList<>(), user,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
 }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Animal.java

@@ -151,13 +151,13 @@ public class Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  mappings.put("Animal", Animal.class);
+    mappings.put("Animal", Animal.class);
-  JSON.registerDiscriminator(Animal.class, "className", mappings);
+    JSON.registerDiscriminator(Animal.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Cat.java

@@ -92,7 +92,7 @@ public class Cat extends Animal {
   @JsonAnySetter
   public Cat putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -160,11 +160,11 @@ public class Cat extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("Cat", Cat.class);
+    mappings.put("Cat", Cat.class);
-  JSON.registerDiscriminator(Cat.class, "className", mappings);
+    JSON.registerDiscriminator(Cat.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ChildCat.java

@@ -135,7 +135,7 @@ public class ChildCat extends ParentPet {
   @JsonAnySetter
   public ChildCat putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -205,11 +205,11 @@ public class ChildCat extends ParentPet {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("ChildCat", ChildCat.class);
+    mappings.put("ChildCat", ChildCat.class);
-  JSON.registerDiscriminator(ChildCat.class, "pet_type", mappings);
+    JSON.registerDiscriminator(ChildCat.class, "pet_type", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java

@@ -111,7 +111,7 @@ public class ComplexQuadrilateral {
   @JsonAnySetter
   public ComplexQuadrilateral putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Dog.java

@@ -92,7 +92,7 @@ public class Dog extends Animal {
   @JsonAnySetter
   public Dog putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -160,11 +160,11 @@ public class Dog extends Animal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("Dog", Dog.class);
+    mappings.put("Dog", Dog.class);
-  JSON.registerDiscriminator(Dog.class, "className", mappings);
+    JSON.registerDiscriminator(Dog.class, "className", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java

@@ -195,7 +195,7 @@ public class Drawing {
   @JsonAnySetter
   public Drawing putAdditionalProperty(String key, Fruit value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Fruit>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EquilateralTriangle.java

@@ -111,7 +111,7 @@ public class EquilateralTriangle {
   @JsonAnySetter
   public EquilateralTriangle putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Fruit.java

@@ -162,7 +162,7 @@ public class Fruit extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Fruit() {
         super("oneOf", Boolean.FALSE);
@@ -201,12 +201,12 @@ public class Fruit extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FruitReq.java

@@ -164,7 +164,7 @@ public class FruitReq extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public FruitReq() {
         super("oneOf", Boolean.TRUE);
@@ -208,12 +208,12 @@ public class FruitReq extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(AppleReq.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(AppleReq.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(BananaReq.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(BananaReq.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GmFruit.java

@@ -122,7 +122,7 @@ public class GmFruit extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in anyOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public GmFruit() {
         super("anyOf", Boolean.FALSE);
@@ -161,12 +161,12 @@ public class GmFruit extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Apple.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Banana.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/GrandparentAnimal.java

@@ -120,13 +120,13 @@ public class GrandparentAnimal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("ChildCat", ChildCat.class);
+    mappings.put("ChildCat", ChildCat.class);
-  mappings.put("ParentPet", ParentPet.class);
+    mappings.put("ParentPet", ParentPet.class);
-  mappings.put("GrandparentAnimal", GrandparentAnimal.class);
+    mappings.put("GrandparentAnimal", GrandparentAnimal.class);
-  JSON.registerDiscriminator(GrandparentAnimal.class, "pet_type", mappings);
+    JSON.registerDiscriminator(GrandparentAnimal.class, "pet_type", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Mammal.java

@@ -215,7 +215,7 @@ public class Mammal extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Mammal() {
         super("oneOf", Boolean.FALSE);
@@ -234,7 +234,7 @@ public class Mammal extends AbstractOpenApiSchema {
   @JsonAnySetter
   public Mammal putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -294,7 +294,7 @@ public class Mammal extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(Mammal.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Pig", Pig.class);
         mappings.put("whale", Whale.class);
         mappings.put("zebra", Zebra.class);
@@ -317,17 +317,17 @@ public class Mammal extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Pig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Pig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Whale.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Whale.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Zebra.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Zebra.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java

@@ -556,7 +556,7 @@ public class NullableClass {
   @JsonAnySetter
   public NullableClass putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableShape.java

@@ -186,7 +186,7 @@ public class NullableShape extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public NullableShape() {
         super("oneOf", Boolean.TRUE);
@@ -205,7 +205,7 @@ public class NullableShape extends AbstractOpenApiSchema {
   @JsonAnySetter
   public NullableShape putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -258,7 +258,7 @@ public class NullableShape extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(NullableShape.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("NullableShape", NullableShape.class);
@@ -285,12 +285,12 @@ public class NullableShape extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ParentPet.java

@@ -67,7 +67,7 @@ public class ParentPet extends GrandparentAnimal {
   @JsonAnySetter
   public ParentPet putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -131,12 +131,12 @@ public class ParentPet extends GrandparentAnimal {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("ChildCat", ChildCat.class);
+    mappings.put("ChildCat", ChildCat.class);
-  mappings.put("ParentPet", ParentPet.class);
+    mappings.put("ParentPet", ParentPet.class);
-  JSON.registerDiscriminator(ParentPet.class, "pet_type", mappings);
+    JSON.registerDiscriminator(ParentPet.class, "pet_type", mappings);
-}
+  }
 }
 

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pig.java

@@ -184,7 +184,7 @@ public class Pig extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Pig() {
         super("oneOf", Boolean.FALSE);
@@ -203,7 +203,7 @@ public class Pig extends AbstractOpenApiSchema {
   @JsonAnySetter
   public Pig putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -256,7 +256,7 @@ public class Pig extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(Pig.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("BasquePig", BasquePig.class);
         mappings.put("DanishPig", DanishPig.class);
         mappings.put("Pig", Pig.class);
@@ -278,12 +278,12 @@ public class Pig extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(BasquePig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(BasquePig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(DanishPig.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(DanishPig.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Quadrilateral.java

@@ -184,7 +184,7 @@ public class Quadrilateral extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Quadrilateral() {
         super("oneOf", Boolean.FALSE);
@@ -203,7 +203,7 @@ public class Quadrilateral extends AbstractOpenApiSchema {
   @JsonAnySetter
   public Quadrilateral putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -256,7 +256,7 @@ public class Quadrilateral extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(Quadrilateral.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("ComplexQuadrilateral", ComplexQuadrilateral.class);
         mappings.put("SimpleQuadrilateral", SimpleQuadrilateral.class);
         mappings.put("Quadrilateral", Quadrilateral.class);
@@ -278,12 +278,12 @@ public class Quadrilateral extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(ComplexQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(ComplexQuadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(SimpleQuadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(SimpleQuadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ScaleneTriangle.java

@@ -111,7 +111,7 @@ public class ScaleneTriangle {
   @JsonAnySetter
   public ScaleneTriangle putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Shape.java

@@ -184,7 +184,7 @@ public class Shape extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Shape() {
         super("oneOf", Boolean.FALSE);
@@ -203,7 +203,7 @@ public class Shape extends AbstractOpenApiSchema {
   @JsonAnySetter
   public Shape putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -256,7 +256,7 @@ public class Shape extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(Shape.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("Shape", Shape.class);
@@ -278,12 +278,12 @@ public class Shape extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ShapeOrNull.java

@@ -186,7 +186,7 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public ShapeOrNull() {
         super("oneOf", Boolean.TRUE);
@@ -205,7 +205,7 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
   @JsonAnySetter
   public ShapeOrNull putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -258,7 +258,7 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(ShapeOrNull.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("Quadrilateral", Quadrilateral.class);
         mappings.put("Triangle", Triangle.class);
         mappings.put("ShapeOrNull", ShapeOrNull.class);
@@ -285,12 +285,12 @@ public class ShapeOrNull extends AbstractOpenApiSchema {
            return;
         }
 
-        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Quadrilateral.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(Triangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java

@@ -111,7 +111,7 @@ public class SimpleQuadrilateral {
   @JsonAnySetter
   public SimpleQuadrilateral putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Triangle.java

@@ -215,7 +215,7 @@ public class Triangle extends AbstractOpenApiSchema {
     }
 
     // store a list of schema names defined in oneOf
-    public static final Map<String, GenericType> schemas = new HashMap<String, GenericType>();
+    public static final Map<String, GenericType> schemas = new HashMap<>();
 
     public Triangle() {
         super("oneOf", Boolean.FALSE);
@@ -234,7 +234,7 @@ public class Triangle extends AbstractOpenApiSchema {
   @JsonAnySetter
   public Triangle putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -294,7 +294,7 @@ public class Triangle extends AbstractOpenApiSchema {
         });
         JSON.registerDescendants(Triangle.class, Collections.unmodifiableMap(schemas));
         // Initialize and register the discriminator mappings.
-        Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+        Map<String, Class<?>> mappings = new HashMap<>();
         mappings.put("EquilateralTriangle", EquilateralTriangle.class);
         mappings.put("IsoscelesTriangle", IsoscelesTriangle.class);
         mappings.put("ScaleneTriangle", ScaleneTriangle.class);
@@ -317,17 +317,17 @@ public class Triangle extends AbstractOpenApiSchema {
      */
     @Override
     public void setActualInstance(Object instance) {
-        if (JSON.isInstanceOf(EquilateralTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(EquilateralTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(IsoscelesTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(IsoscelesTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }
 
-        if (JSON.isInstanceOf(ScaleneTriangle.class, instance, new HashSet<Class<?>>())) {
+        if (JSON.isInstanceOf(ScaleneTriangle.class, instance, new HashSet<>())) {
             super.setActualInstance(instance);
             return;
         }

samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Zebra.java

@@ -149,7 +149,7 @@ public class Zebra {
   @JsonAnySetter
   public Zebra putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;

samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/ApiClient.java

@@ -35,6 +35,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -42,11 +43,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -68,63 +72,58 @@ import org.openapitools.client.auth.ApiKeyAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io:80/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://{server}.swagger.io:{port}/v2",
+                  "http://{server}.swagger.io:{port}/v2",
-      "petstore server",
+                  "petstore server",
-      new HashMap<String, ServerVariable>() {{
+                  Stream.<Entry<String, ServerVariable>>of(
-        put("server", new ServerVariable(
+                          new SimpleEntry<>("server", new ServerVariable(
-          "No description provided",
+                                  "No description provided",
-          "petstore",
+                                  "petstore",
-          new HashSet<String>(
+                                  new LinkedHashSet<>(Arrays.asList(
-            Arrays.asList(
+                                          "petstore",
-              "petstore",
+                                          "qa-petstore",
-              "qa-petstore",
+                                          "dev-petstore"
-              "dev-petstore"
+                                  ))
-            )
+                          )),
+                          new SimpleEntry<>("port", new ServerVariable(
+                                  "No description provided",
+                                  "80",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "80",
+                                          "8080"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
+          ),
+          new ServerConfiguration(
+                  "https://localhost:8080/{version}",
+                  "The local server",
+                  Stream.<Entry<String, ServerVariable>>of(
+                          new SimpleEntry<>("version", new ServerVariable(
+                                  "No description provided",
+                                  "v2",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "v1",
+                                          "v2"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
           )
-        ));
-        put("port", new ServerVariable(
-          "No description provided",
-          "80",
-          new HashSet<String>(
-            Arrays.asList(
-              "80",
-              "8080"
-            )
-          )
-        ));
-      }}
-    ),
-    new ServerConfiguration(
-      "https://localhost:8080/{version}",
-      "The local server",
-      new HashMap<String, ServerVariable>() {{
-        put("version", new ServerVariable(
-          "No description provided",
-          "v2",
-          new HashSet<String>(
-            Arrays.asList(
-              "v1",
-              "v2"
-            )
-          )
-        ));
-      }}
-    )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-  }};
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -161,7 +160,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("api_key");
@@ -183,7 +182,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
     authenticationLookup.put("api_key_query", "api_key");
   }
 
@@ -665,7 +664,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -724,14 +723,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -743,8 +741,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -764,8 +762,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1057,15 +1055,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        null,
+          cookieParams,
-        method,
+          null,
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1237,10 +1237,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/JSON.java

@@ -63,7 +63,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -83,7 +83,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -192,12 +192,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/openapi3/client/extensions/x-auth-id-alias/java/jersey2-java8/src/main/java/org/openapitools/client/api/UsageApi.java

@@ -11,6 +11,7 @@ import javax.ws.rs.core.GenericType;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -71,37 +72,12 @@ public class UsageApi {
      </table>
    */
   public ApiResponse<Object> anyKeyWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key", "api_key_query"};
-    String localVarPath = "/any";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key", "api_key_query" };
-
     GenericType<Object> localVarReturnType = new GenericType<Object>() {};
-
+    return apiClient.invokeAPI("UsageApi.anyKey", "/any", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UsageApi.anyKey", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -131,37 +107,12 @@ public class UsageApi {
      </table>
    */
   public ApiResponse<Object> bothKeysWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key", "api_key_query"};
-    String localVarPath = "/both";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key", "api_key_query" };
-
     GenericType<Object> localVarReturnType = new GenericType<Object>() {};
-
+    return apiClient.invokeAPI("UsageApi.bothKeys", "/both", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UsageApi.bothKeys", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -191,37 +142,12 @@ public class UsageApi {
      </table>
    */
   public ApiResponse<Object> keyInHeaderWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/header";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
     GenericType<Object> localVarReturnType = new GenericType<Object>() {};
-
+    return apiClient.invokeAPI("UsageApi.keyInHeader", "/header", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UsageApi.keyInHeader", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -251,37 +177,12 @@ public class UsageApi {
      </table>
    */
   public ApiResponse<Object> keyInQueryWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key_query"};
-    String localVarPath = "/query";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key_query" };
-
     GenericType<Object> localVarReturnType = new GenericType<Object>() {};
-
+    return apiClient.invokeAPI("UsageApi.keyInQuery", "/query", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UsageApi.keyInQuery", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/ApiClient.java

@@ -35,6 +35,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -42,11 +43,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -68,25 +72,26 @@ import org.openapitools.client.auth.ApiKeyAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://localhost";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "",
+                  "",
-      "No description provided",
+                  "No description provided",
-      new HashMap<String, ServerVariable>()
+                  new LinkedHashMap<>()
-    )
+          )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-  }};
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -123,13 +128,13 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     // Prevent the authentications from being modified.
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -610,7 +615,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -669,14 +674,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -688,8 +692,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -709,8 +713,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1002,15 +1006,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        null,
+          cookieParams,
-        method,
+          null,
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1182,10 +1188,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/JSON.java

@@ -64,7 +64,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -84,7 +84,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -193,12 +193,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/api/DefaultApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.MySchemaNameCharacters;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,37 +75,11 @@ public class DefaultApi {
      </table>
    */
   public ApiResponse<MySchemaNameCharacters> testPostWithHttpInfo(MySchemaNameCharacters mySchemaNameCharacters) throws ApiException {
-    Object localVarPostBody = mySchemaNameCharacters;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    // create path and map variables
-    String localVarPath = "/test";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<MySchemaNameCharacters> localVarReturnType = new GenericType<MySchemaNameCharacters>() {};
-
+    return apiClient.invokeAPI("DefaultApi.testPost", "/test", "POST", new ArrayList<>(), mySchemaNameCharacters,
-    return apiClient.invokeAPI("DefaultApi.testPost", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/ChildSchema.java

@@ -92,7 +92,7 @@ public class ChildSchema extends Parent {
   @JsonAnySetter
   public ChildSchema putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -160,11 +160,11 @@ public class ChildSchema extends Parent {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("ChildSchema", ChildSchema.class);
+    mappings.put("ChildSchema", ChildSchema.class);
-  JSON.registerDiscriminator(ChildSchema.class, "objectType", mappings);
+    JSON.registerDiscriminator(ChildSchema.class, "objectType", mappings);
-}
+  }
 }
 

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/MySchemaNameCharacters.java

@@ -93,7 +93,7 @@ public class MySchemaNameCharacters extends Parent {
   @JsonAnySetter
   public MySchemaNameCharacters putAdditionalProperty(String key, Object value) {
     if (this.additionalProperties == null) {
-        this.additionalProperties = new HashMap<String, Object>();
+        this.additionalProperties = new HashMap<>();
     }
     this.additionalProperties.put(key, value);
     return this;
@@ -161,11 +161,11 @@ public class MySchemaNameCharacters extends Parent {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("MySchemaName._-Characters", MySchemaNameCharacters.class);
+    mappings.put("MySchemaName._-Characters", MySchemaNameCharacters.class);
-  JSON.registerDiscriminator(MySchemaNameCharacters.class, "objectType", mappings);
+    JSON.registerDiscriminator(MySchemaNameCharacters.class, "objectType", mappings);
-}
+  }
 }
 

samples/openapi3/client/petstore/java/jersey2-java8-special-characters/src/main/java/org/openapitools/client/model/Parent.java

@@ -120,13 +120,13 @@ public class Parent {
     return o.toString().replace("\n", "\n    ");
   }
 
-static {
+  static {
-  // Initialize and register the discriminator mappings.
+    // Initialize and register the discriminator mappings.
-  Map<String, Class<?>> mappings = new HashMap<String, Class<?>>();
+    Map<String, Class<?>> mappings = new HashMap<>();
-  mappings.put("ChildSchema", ChildSchema.class);
+    mappings.put("ChildSchema", ChildSchema.class);
-  mappings.put("MySchemaName._-Characters", MySchemaNameCharacters.class);
+    mappings.put("MySchemaName._-Characters", MySchemaNameCharacters.class);
-  mappings.put("Parent", Parent.class);
+    mappings.put("Parent", Parent.class);
-  JSON.registerDiscriminator(Parent.class, "objectType", mappings);
+    JSON.registerDiscriminator(Parent.class, "objectType", mappings);
-}
+  }
 }
 

samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/ApiClient.java

@@ -36,6 +36,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -43,11 +44,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -70,25 +74,26 @@ import org.openapitools.client.auth.OAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://petstore.swagger.io/v2",
+                  "http://petstore.swagger.io/v2",
-      "No description provided",
+                  "No description provided",
-      new HashMap<String, ServerVariable>()
+                  new LinkedHashMap<>()
-    )
+          )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-  }};
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -125,7 +130,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("petstore_auth");
@@ -147,7 +152,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -735,7 +740,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -794,14 +799,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -813,8 +817,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -834,8 +838,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1127,15 +1131,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        null,
+          cookieParams,
-        method,
+          null,
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1152,7 +1158,7 @@ public class ApiClient extends JavaTimeFormatter {
       final int statusCode = response.getStatusInfo().getStatusCode();
 
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1323,10 +1329,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }

samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/JSON.java

@@ -64,7 +64,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
   public static Class<?> getClassForElement(JsonNode node, Class<?> modelClass) {
     ClassDiscriminatorMapping cdm = modelDiscriminators.get(modelClass);
     if (cdm != null) {
-      return cdm.getClassForElement(node, new HashSet<Class<?>>());
+      return cdm.getClassForElement(node, new HashSet<>());
     }
     return null;
   }
@@ -84,7 +84,7 @@ public class JSON implements ContextResolver<ObjectMapper> {
     ClassDiscriminatorMapping(Class<?> cls, String propertyName, Map<String, Class<?>> mappings) {
       modelClass = cls;
       discriminatorName = propertyName;
-      discriminatorMappings = new HashMap<String, Class<?>>();
+      discriminatorMappings = new HashMap<>();
       if (mappings != null) {
         discriminatorMappings.putAll(mappings);
       }
@@ -193,12 +193,12 @@ public class JSON implements ContextResolver<ObjectMapper> {
   /**
    * A map of discriminators for all model classes.
    */
-  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<Class<?>, ClassDiscriminatorMapping>();
+  private static Map<Class<?>, ClassDiscriminatorMapping> modelDiscriminators = new HashMap<>();
 
   /**
    * A map of oneOf/anyOf descendants for each model class.
    */
-  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<Class<?>, Map<String, GenericType>>();
+  private static Map<Class<?>, Map<String, GenericType>> modelDescendants = new HashMap<>();
 
   /**
     * Register a model class discriminator.

samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/api/PetApi.java

@@ -14,6 +14,7 @@ import org.openapitools.client.model.Pet;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -78,42 +79,17 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Pet> addPetWithHttpInfo(Pet pet) throws ApiException {
-    Object localVarPostBody = pet;
+    // Check required parameters
-    
-    // verify the required parameter 'pet' is set
     if (pet == null) {
       throw new ApiException(400, "Missing the required parameter 'pet' when calling addPet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.addPet", "/pet", "POST", new ArrayList<>(), pet,
-    return apiClient.invokeAPI("PetApi.addPet", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -146,43 +122,26 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> deletePetWithHttpInfo(Long petId, String apiKey) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling deletePet");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Header parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (apiKey != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    if (apiKey != null)
       localVarHeaderParams.put("api_key", apiClient.parameterToString(apiKey));
+    }
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    final String[] localVarAccepts = {
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-      
+    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", new ArrayList<>(), null,
-    };
+                               localVarHeaderParams, new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.deletePet", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -216,43 +175,22 @@ public class PetApi {
      </table>
    */
   public ApiResponse<List<Pet>> findPetsByStatusWithHttpInfo(List<String> status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'status' is set
     if (status == null) {
       throw new ApiException(400, "Missing the required parameter 'status' when calling findPetsByStatus");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByStatus";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "status", status)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "status", status));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByStatus", "/pet/findByStatus", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByStatus", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -290,43 +228,22 @@ public class PetApi {
    */
   @Deprecated
   public ApiResponse<List<Pet>> findPetsByTagsWithHttpInfo(List<String> tags) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'tags' is set
     if (tags == null) {
       throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet/findByTags";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("csv", "tags", tags)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("csv", "tags", tags));
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
-
+    return apiClient.invokeAPI("PetApi.findPetsByTags", "/pet/findByTags", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("PetApi.findPetsByTags", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -362,43 +279,21 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Pet> getPetByIdWithHttpInfo(Long petId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling getPetById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
+    String[] localVarAuthNames = new String[] {"api_key"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.getPetById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -440,42 +335,17 @@ public class PetApi {
    * @see <a href="http://petstore.swagger.io/v2/doc/updatePet">Update an existing pet Documentation</a>
    */
   public ApiResponse<Pet> updatePetWithHttpInfo(Pet pet) throws ApiException {
-    Object localVarPostBody = pet;
+    // Check required parameters
-    
-    // verify the required parameter 'pet' is set
     if (pet == null) {
       throw new ApiException(400, "Missing the required parameter 'pet' when calling updatePet");
     }
-    
-    // create path and map variables
-    String localVarPath = "/pet";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json", "application/xml"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json", "application/xml");
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
     GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
-
+    return apiClient.invokeAPI("PetApi.updatePet", "/pet", "PUT", new ArrayList<>(), pet,
-    return apiClient.invokeAPI("PetApi.updatePet", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -510,45 +380,29 @@ public class PetApi {
      </table>
    */
   public ApiResponse<Void> updatePetWithFormWithHttpInfo(Long petId, String name, String status) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling updatePetWithForm");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (name != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (name != null)
       localVarFormParams.put("name", name);
-if (status != null)
+    }
+    if (status != null) {
       localVarFormParams.put("status", status);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept();
-      
+    String localVarContentType = apiClient.selectHeaderContentType("application/x-www-form-urlencoded");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-    final String[] localVarContentTypes = {
-      "application/x-www-form-urlencoded"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
-    return apiClient.invokeAPI("PetApi.updatePetWithForm", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -584,47 +438,30 @@ if (status != null)
      </table>
    */
   public ApiResponse<ModelApiResponse> uploadFileWithHttpInfo(Long petId, String additionalMetadata, File _file) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'petId' is set
     if (petId == null) {
       throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFile");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/pet/{petId}/uploadImage"
-      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+            .replaceAll("\\{petId}", apiClient.escapeString(petId.toString()));
 
-    // query params
+    // Form parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    Map<String, Object> localVarFormParams = new LinkedHashMap<>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    if (additionalMetadata != null) {
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    if (additionalMetadata != null)
       localVarFormParams.put("additionalMetadata", additionalMetadata);
-if (_file != null)
+    }
+    if (_file != null) {
       localVarFormParams.put("file", _file);
+    }
 
-    final String[] localVarAccepts = {
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-      "application/json"
+    String localVarContentType = apiClient.selectHeaderContentType("multipart/form-data");
-    };
+    String[] localVarAuthNames = new String[] {"petstore_auth"};
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "multipart/form-data"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "petstore_auth" };
-
     GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
-
+    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", new ArrayList<>(), null,
-    return apiClient.invokeAPI("PetApi.uploadFile", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), localVarFormParams, localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
 }

samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -12,6 +12,7 @@ import org.openapitools.client.model.Order;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -75,42 +76,20 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Void> deleteOrderWithHttpInfo(String orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling deleteOrder");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{orderId}"
-      .replaceAll("\\{" + "orderId" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{orderId}", apiClient.escapeString(orderId));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               null, null, false);
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
-    return apiClient.invokeAPI("StoreApi.deleteOrder", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
-                               localVarAuthNames, null, false);
   }
   /**
    * Returns pet inventories by status
@@ -139,37 +118,12 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Map<String, Integer>> getInventoryWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept("application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/store/inventory";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
     GenericType<Map<String, Integer>> localVarReturnType = new GenericType<Map<String, Integer>>() {};
-
+    return apiClient.invokeAPI("StoreApi.getInventory", "/store/inventory", "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getInventory", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, localVarReturnType, false);
   }
   /**
@@ -205,44 +159,21 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> getOrderByIdWithHttpInfo(Long orderId) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'orderId' is set
     if (orderId == null) {
       throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/store/order/{orderId}"
-      .replaceAll("\\{" + "orderId" + "\\}", apiClient.escapeString(orderId.toString()));
+            .replaceAll("\\{orderId}", apiClient.escapeString(orderId.toString()));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("StoreApi.getOrderById", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Place an order for a pet
@@ -275,42 +206,16 @@ public class StoreApi {
      </table>
    */
   public ApiResponse<Order> placeOrderWithHttpInfo(Order order) throws ApiException {
-    Object localVarPostBody = order;
+    // Check required parameters
-    
-    // verify the required parameter 'order' is set
     if (order == null) {
       throw new ApiException(400, "Missing the required parameter 'order' when calling placeOrder");
     }
-    
-    // create path and map variables
-    String localVarPath = "/store/order";
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
     GenericType<Order> localVarReturnType = new GenericType<Order>() {};
-
+    return apiClient.invokeAPI("StoreApi.placeOrder", "/store/order", "POST", new ArrayList<>(), order,
-    return apiClient.invokeAPI("StoreApi.placeOrder", localVarPath, "POST", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
 }

samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/api/UserApi.java

@@ -13,6 +13,7 @@ import org.openapitools.client.model.User;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -74,40 +75,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUserWithHttpInfo(User user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"api_key"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUser", "/user", "POST", new ArrayList<>(), user,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.createUser", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -138,40 +115,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUsersWithArrayInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithArray";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"api_key"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", "/user/createWithArray", "POST", new ArrayList<>(), user,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithArrayInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -202,40 +155,16 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> createUsersWithListInputWithHttpInfo(List<User> user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling createUsersWithListInput");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/createWithList";
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"api_key"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.createUsersWithListInput", "/user/createWithList", "POST", new ArrayList<>(), user,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.createUsersWithListInput", localVarPath, "POST", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -268,41 +197,20 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> deleteUserWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling deleteUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"api_key"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", new ArrayList<>(), null,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.deleteUser", localVarPath, "DELETE", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -338,44 +246,21 @@ public class UserApi {
      </table>
    */
   public ApiResponse<User> getUserByNameWithHttpInfo(String username) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling getUserByName");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
-
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
 
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
+    String localVarContentType = apiClient.selectHeaderContentType();
     GenericType<User> localVarReturnType = new GenericType<User>() {};
-
+    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", new ArrayList<>(), null,
-    return apiClient.invokeAPI("UserApi.getUserByName", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs user into the system
@@ -410,50 +295,26 @@ public class UserApi {
      </table>
    */
   public ApiResponse<String> loginUserWithHttpInfo(String username, String password) throws ApiException {
-    Object localVarPostBody = null;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling loginUser");
     }
-    
-    // verify the required parameter 'password' is set
     if (password == null) {
       throw new ApiException(400, "Missing the required parameter 'password' when calling loginUser");
     }
-    
-    // create path and map variables
-    String localVarPath = "/user/login";
 
-    // query params
+    // Query parameters
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarQueryParams = new ArrayList<>(
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+            apiClient.parameterToPairs("", "username", username)
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    );
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-    localVarQueryParams.addAll(apiClient.parameterToPairs("", "username", username));
     localVarQueryParams.addAll(apiClient.parameterToPairs("", "password", password));
 
-    
+    String localVarAccept = apiClient.selectHeaderAccept("application/xml", "application/json");
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    
-    final String[] localVarAccepts = {
-      "application/xml", "application/json"
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] {  };
-
     GenericType<String> localVarReturnType = new GenericType<String>() {};
-
+    return apiClient.invokeAPI("UserApi.loginUser", "/user/login", "GET", localVarQueryParams, null,
-    return apiClient.invokeAPI("UserApi.loginUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
+                               null, localVarReturnType, false);
-                               localVarAuthNames, localVarReturnType, false);
   }
   /**
    * Logs out current logged in user session
@@ -481,35 +342,11 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> logoutUserWithHttpInfo() throws ApiException {
-    Object localVarPostBody = null;
+    String localVarAccept = apiClient.selectHeaderAccept();
-    
+    String localVarContentType = apiClient.selectHeaderContentType();
-    // create path and map variables
+    String[] localVarAuthNames = new String[] {"api_key"};
-    String localVarPath = "/user/logout";
+    return apiClient.invokeAPI("UserApi.logoutUser", "/user/logout", "GET", new ArrayList<>(), null,
-
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-    // query params
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.logoutUser", localVarPath, "GET", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
   /**
@@ -544,46 +381,23 @@ public class UserApi {
      </table>
    */
   public ApiResponse<Void> updateUserWithHttpInfo(String username, User user) throws ApiException {
-    Object localVarPostBody = user;
+    // Check required parameters
-    
-    // verify the required parameter 'username' is set
     if (username == null) {
       throw new ApiException(400, "Missing the required parameter 'username' when calling updateUser");
     }
-    
-    // verify the required parameter 'user' is set
     if (user == null) {
       throw new ApiException(400, "Missing the required parameter 'user' when calling updateUser");
     }
-    
+
-    // create path and map variables
+    // Path parameters
     String localVarPath = "/user/{username}"
-      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+            .replaceAll("\\{username}", apiClient.escapeString(username));
 
-    // query params
+    String localVarAccept = apiClient.selectHeaderAccept();
-    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    String localVarContentType = apiClient.selectHeaderContentType("application/json");
-    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    String[] localVarAuthNames = new String[] {"api_key"};
-    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", new ArrayList<>(), user,
-    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+                               new LinkedHashMap<>(), new LinkedHashMap<>(), new LinkedHashMap<>(), localVarAccept, localVarContentType,
-
-
-    
-    
-    
-    final String[] localVarAccepts = {
-      
-    };
-    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
-
-    final String[] localVarContentTypes = {
-      "application/json"
-    };
-    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
-
-    String[] localVarAuthNames = new String[] { "api_key" };
-
-    return apiClient.invokeAPI("UserApi.updateUser", localVarPath, "PUT", localVarQueryParams, localVarPostBody,
-                               localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType,
                                localVarAuthNames, null, false);
   }
 }

samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/ApiClient.java

@@ -36,6 +36,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import org.glassfish.jersey.logging.LoggingFeature;
+import java.util.AbstractMap.SimpleEntry;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.Collection;
@@ -43,11 +44,14 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.HashMap;
-import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Arrays;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.time.OffsetDateTime;
 
 import java.net.URLEncoder;
@@ -71,94 +75,93 @@ import org.openapitools.client.auth.OAuth;
  */
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
 public class ApiClient extends JavaTimeFormatter {
-  protected Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private static final Pattern JSON_MIME_PATTERN = Pattern.compile("(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$");
-  protected Map<String, String> defaultCookieMap = new HashMap<String, String>();
+
+  protected Map<String, String> defaultHeaderMap = new HashMap<>();
+  protected Map<String, String> defaultCookieMap = new HashMap<>();
   protected String basePath = "http://petstore.swagger.io:80/v2";
   protected String userAgent;
   private static final Logger log = Logger.getLogger(ApiClient.class.getName());
 
-  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+  protected List<ServerConfiguration> servers = new ArrayList<>(Arrays.asList(
-    new ServerConfiguration(
+          new ServerConfiguration(
-      "http://{server}.swagger.io:{port}/v2",
+                  "http://{server}.swagger.io:{port}/v2",
-      "petstore server",
+                  "petstore server",
-      new HashMap<String, ServerVariable>() {{
+                  Stream.<Entry<String, ServerVariable>>of(
-        put("server", new ServerVariable(
+                          new SimpleEntry<>("server", new ServerVariable(
-          "No description provided",
+                                  "No description provided",
-          "petstore",
+                                  "petstore",
-          new HashSet<String>(
+                                  new LinkedHashSet<>(Arrays.asList(
-            Arrays.asList(
+                                          "petstore",
-              "petstore",
+                                          "qa-petstore",
-              "qa-petstore",
+                                          "dev-petstore"
-              "dev-petstore"
+                                  ))
-            )
+                          )),
+                          new SimpleEntry<>("port", new ServerVariable(
+                                  "No description provided",
+                                  "80",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "80",
+                                          "8080"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
+          ),
+          new ServerConfiguration(
+                  "https://localhost:8080/{version}",
+                  "The local server",
+                  Stream.<Entry<String, ServerVariable>>of(
+                          new SimpleEntry<>("version", new ServerVariable(
+                                  "No description provided",
+                                  "v2",
+                                  new LinkedHashSet<>(Arrays.asList(
+                                          "v1",
+                                          "v2"
+                                  ))
+                          ))
+                  ).collect(Collectors.toMap(Entry::getKey, Entry::getValue, (a, b) -> a, LinkedHashMap::new))
+          ),
+          new ServerConfiguration(
+                  "https://127.0.0.1/no_variable",
+                  "The local server without variables",
+                  new LinkedHashMap<>()
           )
-        ));
-        put("port", new ServerVariable(
-          "No description provided",
-          "80",
-          new HashSet<String>(
-            Arrays.asList(
-              "80",
-              "8080"
-            )
-          )
-        ));
-      }}
-    ),
-    new ServerConfiguration(
-      "https://localhost:8080/{version}",
-      "The local server",
-      new HashMap<String, ServerVariable>() {{
-        put("version", new ServerVariable(
-          "No description provided",
-          "v2",
-          new HashSet<String>(
-            Arrays.asList(
-              "v1",
-              "v2"
-            )
-          )
-        ));
-      }}
-    ),
-    new ServerConfiguration(
-      "https://127.0.0.1/no_variable",
-      "The local server without variables",
-      new HashMap<String, ServerVariable>()
-    )
   ));
   protected Integer serverIndex = 0;
   protected Map<String, String> serverVariables = null;
-  protected Map<String, List<ServerConfiguration>> operationServers = new HashMap<String, List<ServerConfiguration>>() {{
+  protected Map<String, List<ServerConfiguration>> operationServers;
-    put("PetApi.addPet", new ArrayList<ServerConfiguration>(Arrays.asList(
-      new ServerConfiguration(
-        "http://petstore.swagger.io/v2",
-        "No description provided",
-        new HashMap<String, ServerVariable>()
-      ),
 
-      new ServerConfiguration(
+  {
-        "http://path-server-test.petstore.local/v2",
+    Map<String, List<ServerConfiguration>> operationServers = new HashMap<>();
-        "No description provided",
+    operationServers.put("PetApi.addPet", new ArrayList<>(Arrays.asList(
-        new HashMap<String, ServerVariable>()
+            new ServerConfiguration(
-      )
+                    "http://petstore.swagger.io/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            ),
+            new ServerConfiguration(
+                    "http://path-server-test.petstore.local/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            )
     )));
-    put("PetApi.updatePet", new ArrayList<ServerConfiguration>(Arrays.asList(
+    operationServers.put("PetApi.updatePet", new ArrayList<>(Arrays.asList(
-      new ServerConfiguration(
+            new ServerConfiguration(
-        "http://petstore.swagger.io/v2",
+                    "http://petstore.swagger.io/v2",
-        "No description provided",
+                    "No description provided",
-        new HashMap<String, ServerVariable>()
+                    new LinkedHashMap<>()
-      ),
+            ),
+            new ServerConfiguration(
+                    "http://path-server-test.petstore.local/v2",
+                    "No description provided",
+                    new LinkedHashMap<>()
+            )
+    )));
+    this.operationServers = operationServers;
+  }
 
-      new ServerConfiguration(
+  protected Map<String, Integer> operationServerIndex = new HashMap<>();
-        "http://path-server-test.petstore.local/v2",
+  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<>();
-        "No description provided",
-        new HashMap<String, ServerVariable>()
-      )
-    )));
-  }};
-  protected Map<String, Integer> operationServerIndex = new HashMap<String, Integer>();
-  protected Map<String, Map<String, String>> operationServerVariables = new HashMap<String, Map<String, String>>();
   protected boolean debugging = false;
   protected ClientConfig clientConfig;
   protected int connectionTimeout = 0;
@@ -195,7 +198,7 @@ public class ApiClient extends JavaTimeFormatter {
     setUserAgent("OpenAPI-Generator/1.0.0/java");
 
     // Setup authentications (key: authentication name, value: authentication).
-    authentications = new HashMap<String, Authentication>();
+    authentications = new HashMap<>();
     Authentication auth = null;
     if (authMap != null) {
       auth = authMap.get("petstore_auth");
@@ -247,7 +250,7 @@ public class ApiClient extends JavaTimeFormatter {
     authentications = Collections.unmodifiableMap(authentications);
 
     // Setup authentication lookup (key: authentication alias, value: authentication name)
-    authenticationLookup = new HashMap<String, String>();
+    authenticationLookup = new HashMap<>();
   }
 
   /**
@@ -835,7 +838,7 @@ public class ApiClient extends JavaTimeFormatter {
    * @return List of pairs
    */
   public List<Pair> parameterToPairs(String collectionFormat, String name, Object value){
-    List<Pair> params = new ArrayList<Pair>();
+    List<Pair> params = new ArrayList<>();
 
     // preconditions
     if (name == null || name.isEmpty() || value == null) return params;
@@ -894,14 +897,13 @@ public class ApiClient extends JavaTimeFormatter {
    *   application/json; charset=UTF8
    *   APPLICATION/JSON
    *   application/vnd.company+json
-   * "* / *" is also default to JSON
+   * "*{@literal /}*" is also considered JSON by this method.
    *
    * @param mime MIME
    * @return True if the MIME type is JSON
    */
   public boolean isJsonMime(String mime) {
-    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.equals("*/*") || JSON_MIME_PATTERN.matcher(mime).matches());
-    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
   }
 
   /**
@@ -913,8 +915,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Accept header to use. If the given array is empty,
    *   null will be returned (not to set the Accept header explicitly).
    */
-  public String selectHeaderAccept(String[] accepts) {
+  public String selectHeaderAccept(String... accepts) {
-    if (accepts.length == 0) {
+    if (accepts == null || accepts.length == 0) {
       return null;
     }
     for (String accept : accepts) {
@@ -934,8 +936,8 @@ public class ApiClient extends JavaTimeFormatter {
    * @return The Content-Type header to use. If the given array is empty,
    *   JSON will be used.
    */
-  public String selectHeaderContentType(String[] contentTypes) {
+  public String selectHeaderContentType(String... contentTypes) {
-    if (contentTypes.length == 0) {
+    if (contentTypes == null || contentTypes.length == 0) {
       return "application/json";
     }
     for (String contentType : contentTypes) {
@@ -1227,15 +1229,17 @@ public class ApiClient extends JavaTimeFormatter {
     Map<String, String> allHeaderParams = new HashMap<>(defaultHeaderMap);
     allHeaderParams.putAll(headerParams);
 
-    // update different parameters (e.g. headers) for authentication
+    if (authNames != null) {
-    updateParamsForAuth(
+      // update different parameters (e.g. headers) for authentication
-        authNames,
+      updateParamsForAuth(
-        queryParams,
+          authNames,
-        allHeaderParams,
+          queryParams,
-        cookieParams,
+          allHeaderParams,
-        serializeToString(body, formParams, contentType, isBodyNullable),
+          cookieParams,
-        method,
+          serializeToString(body, formParams, contentType, isBodyNullable),
-        target.getUri());
+          method,
+          target.getUri());
+    }
 
     for (Entry<String, String> entry : allHeaderParams.entrySet()) {
       String value = entry.getValue();
@@ -1252,7 +1256,7 @@ public class ApiClient extends JavaTimeFormatter {
       final int statusCode = response.getStatusInfo().getStatusCode();
 
       // If OAuth is used and a status 401 is received, renew the access token and retry the request
-      if (statusCode == Status.UNAUTHORIZED.getStatusCode()) {
+      if (authNames != null && statusCode == Status.UNAUTHORIZED.getStatusCode()) {
         for (String authName : authNames) {
           Authentication authentication = authentications.get(authName);
           if (authentication instanceof OAuth) {
@@ -1423,10 +1427,10 @@ public class ApiClient extends JavaTimeFormatter {
    * @return a {@link java.util.Map} of response headers.
    */
   protected Map<String, List<String>> buildResponseHeaders(Response response) {
-    Map<String, List<String>> responseHeaders = new HashMap<String, List<String>>();
+    Map<String, List<String>> responseHeaders = new HashMap<>();
     for (Entry<String, List<Object>> entry: response.getHeaders().entrySet()) {
       List<Object> values = entry.getValue();
-      List<String> headers = new ArrayList<String>();
+      List<String> headers = new ArrayList<>();
       for (Object o : values) {
         headers.add(String.valueOf(o));
       }