[Java][Feign] Expose response headers for feign client (#10507)

* Add .circleci/config.yml

* Add the property exposeResponseHeaders to feign client

This new property indicates if the feign client should expose the response headers on the API class.

* Generate new docs for exposeResponseHeaders additional property

* Rename HeaderAwareResponse to HttpResponse

* Update samples

* Refactor the implementation to use the same approach as the c# generator.
Creates a new feign operation with the suffix WithHttpInfo, this operation returns the response encapsulated in a HttpResponse class.
The HttpResponse class contains the decoded body and the response headers

* Refactor the implementation to use the same approach as the c# generator.
Generate samples

* Refactor the implementation to use the same approach as the c# generator.
Generate docs

* Use Void instead of void for HttpResponse parameterized type

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

@@ -328,6 +328,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
 
         final String invokerFolder = (sourceFolder + '/' + invokerPackage).replace(".", "/");
         final String apiFolder = (sourceFolder + '/' + apiPackage).replace(".", "/");
+        final String modelsFolder = (sourceFolder + File.separator + modelPackage().replace('.', File.separatorChar)).replace('/', File.separatorChar);
         authFolder = (sourceFolder + '/' + invokerPackage + ".auth").replace(".", "/");
 
         //Common files
@@ -387,6 +388,9 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         if (FEIGN.equals(getLibrary())) {
             modelDocTemplateFiles.remove("model_doc.mustache");
             apiDocTemplateFiles.remove("api_doc.mustache");
+            //Templates to decode response headers
+            supportingFiles.add(new SupportingFile("model/HttpResponse.mustache", modelsFolder, "HttpResponse.java"));
+            supportingFiles.add(new SupportingFile("JacksonResponseDecoder.mustache", invokerFolder, "JacksonResponseDecoder.java"));
         }
 
         if (!(FEIGN.equals(getLibrary()) || RESTTEMPLATE.equals(getLibrary()) || RETROFIT_2.equals(getLibrary()) || GOOGLE_API_CLIENT.equals(getLibrary()) || REST_ASSURED.equals(getLibrary()) || WEBCLIENT.equals(getLibrary()) || MICROPROFILE.equals(getLibrary()))) {
@@ -431,7 +435,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             if (ProcessUtils.hasHttpSignatureMethods(openAPI)) {
                 supportingFiles.add(new SupportingFile("auth/HttpSignatureAuth.mustache", authFolder, "HttpSignatureAuth.java"));
             }
-            supportingFiles.add(new SupportingFile("AbstractOpenApiSchema.mustache", (sourceFolder + File.separator + modelPackage().replace('.', File.separatorChar)).replace('/', File.separatorChar), "AbstractOpenApiSchema.java"));
+            supportingFiles.add(new SupportingFile("AbstractOpenApiSchema.mustache", modelsFolder, "AbstractOpenApiSchema.java"));
             forceSerializationLibrary(SERIALIZATION_LIBRARY_JACKSON);
 
             // Composed schemas can have the 'additionalProperties' keyword, as specified in JSON schema.
@@ -445,7 +449,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
             setJava8ModeAndAdditionalProperties(true);
             supportingFiles.add(new SupportingFile("ApiResponse.mustache", invokerFolder, "ApiResponse.java"));
             supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
-            supportingFiles.add(new SupportingFile("AbstractOpenApiSchema.mustache", (sourceFolder + File.separator + modelPackage().replace('.', File.separatorChar)).replace('/', File.separatorChar), "AbstractOpenApiSchema.java"));
+            supportingFiles.add(new SupportingFile("AbstractOpenApiSchema.mustache", modelsFolder, "AbstractOpenApiSchema.java"));
             forceSerializationLibrary(SERIALIZATION_LIBRARY_JACKSON);
         } else if (RESTEASY.equals(getLibrary())) {
             setJava8ModeAndAdditionalProperties(true);

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

@@ -35,6 +35,7 @@ import feign.slf4j.Slf4jLogger;
 import {{invokerPackage}}.auth.HttpBasicAuth;
 import {{invokerPackage}}.auth.HttpBearerAuth;
 import {{invokerPackage}}.auth.ApiKeyAuth;
+import {{invokerPackage}}.JacksonResponseDecoder;
 
 {{#hasOAuthMethods}}
 import {{invokerPackage}}.auth.ApiErrorDecoder;
@@ -63,7 +64,7 @@ public class ApiClient {
     feignBuilder = Feign.builder()
                 .client(new OkHttpClient())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
-                .decoder(new JacksonDecoder(objectMapper))
+                .decoder(new JacksonResponseDecoder(objectMapper))
                 {{#hasOAuthMethods}}
                 .errorDecoder(new ApiErrorDecoder())
                 .retryer(new Retryer.Default(0, 0, 2))

modules/openapi-generator/src/main/resources/Java/libraries/feign/JacksonResponseDecoder.mustache

@@ -0,0 +1,38 @@
+package {{invokerPackage}};
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.Response;
+import feign.Types;
+import feign.jackson.JacksonDecoder;
+
+import java.io.IOException;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+import {{modelPackage}}.HttpResponse;
+
+public class JacksonResponseDecoder extends JacksonDecoder {
+
+    public JacksonResponseDecoder(ObjectMapper mapper) {
+        super(mapper);
+    }
+
+    @Override
+    public Object decode(Response response, Type type) throws IOException {
+    Map<String, Collection<String>> responseHeaders = Collections.unmodifiableMap(response.headers());
+        //Detects if the type is an instance of the parameterized class HttpResponse
+        Type responseBodyType;
+        if (Types.getRawType(type).isAssignableFrom(HttpResponse.class)) {
+            //The HttpResponse class has a single type parameter, the Dto class itself
+            responseBodyType = ((ParameterizedType) type).getActualTypeArguments()[0];
+            Object body = super.decode(response, responseBodyType);
+            return new HttpResponse(responseHeaders, body);
+        } else {
+            //The response is not encapsulated in the HttpResponse, decode the Dto as normal
+            return super.decode(response, type);
+        }
+    }
+}

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

@@ -5,6 +5,7 @@ import {{invokerPackage}}.EncodingUtils;
 {{#legacyDates}}
 import {{invokerPackage}}.ParamExpander;
 {{/legacyDates}}
+import {{modelPackage}}.HttpResponse;
 
 {{#imports}}import {{import}};
 {{/imports}}
@@ -49,8 +50,39 @@ public interface {{classname}} extends ApiClient.Api {
     {{/-last}}{{/headerParams}}
   })
   {{#returnType}}{{{.}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{nickname}}({{#allParams}}{{^isBodyParam}}{{^legacyDates}}@Param("{{paramName}}") {{/legacyDates}}{{#legacyDates}}@Param(value="{{paramName}}", expander=ParamExpander.class) {{/legacyDates}}{{/isBodyParam}}{{{dataType}}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}});
-    {{#hasQueryParams}}
 
+  /**
+   * {{summary}}
+   * Similar to <code>{{operationId}}</code> but it also returns the http response headers .
+   * {{notes}}
+{{#allParams}}
+   * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}
+{{/allParams}}
+{{#returnType}}
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+{{/returnType}}
+{{#externalDocs}}
+   * {{description}}
+   * @see <a href="{{url}}">{{summary}} Documentation</a>
+{{/externalDocs}}
+{{#isDeprecated}}
+   * @deprecated
+{{/isDeprecated}}
+   */
+{{#isDeprecated}}
+  @Deprecated
+{{/isDeprecated}}
+  @RequestLine("{{httpMethod}} {{{path}}}{{#hasQueryParams}}?{{/hasQueryParams}}{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
+  @Headers({
+{{#vendorExtensions.x-contentType}}    "Content-Type: {{vendorExtensions.x-contentType}}",
+{{/vendorExtensions.x-contentType}}    "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+    "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
+    {{/-last}}{{/headerParams}}
+  })
+  HttpResponse<{{#returnType}}{{{.}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{nickname}}WithHttpInfo({{#allParams}}{{^isBodyParam}}{{^legacyDates}}@Param("{{paramName}}") {{/legacyDates}}{{#legacyDates}}@Param(value="{{paramName}}", expander=ParamExpander.class) {{/legacyDates}}{{/isBodyParam}}{{{dataType}}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}});
+
+
+  {{#hasQueryParams}}
   /**
    * {{summary}}
    * {{notes}}
@@ -95,6 +127,47 @@ public interface {{classname}} extends ApiClient.Api {
   {{#returnType}}{{{.}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{nickname}}({{#allParams}}{{^isQueryParam}}{{^isBodyParam}}{{^legacyDates}}@Param("{{paramName}}") {{/legacyDates}}{{#legacyDates}}@Param(value="{{paramName}}", expander=ParamExpander.class) {{/legacyDates}}{{/isBodyParam}}{{{dataType}}} {{paramName}}, {{/isQueryParam}}{{/allParams}}@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * {{summary}}
+  * {{notes}}
+  * Note, this is equivalent to the other <code>{{operationId}}</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+  {{#allParams}}
+      {{^isQueryParam}}
+              * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}
+      {{/isQueryParam}}
+  {{/allParams}}
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+      {{#queryParams}}
+          *   <li>{{paramName}} - {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}{{/isContainer}}){{/required}}</li>
+      {{/queryParams}}
+      *   </ul>
+  {{#returnType}}
+          * @return {{.}}
+  {{/returnType}}
+  {{#externalDocs}}
+          * {{description}}
+          * @see <a href="{{url}}">{{summary}} Documentation</a>
+  {{/externalDocs}}
+  {{#isDeprecated}}
+          * @deprecated
+  {{/isDeprecated}}
+      */
+  {{#isDeprecated}}
+          @Deprecated
+  {{/isDeprecated}}
+      @RequestLine("{{httpMethod}} {{{path}}}?{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
+      @Headers({
+  {{#vendorExtensions.x-contentType}}  "Content-Type: {{vendorExtensions.x-contentType}}",
+  {{/vendorExtensions.x-contentType}}  "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+          "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
+      {{/-last}}{{/headerParams}}
+      })
+   HttpResponse<{{#returnType}}{{{.}}}{{/returnType}}{{^returnType}}Void{{/returnType}}> {{nickname}}WithHttpInfo({{#allParams}}{{^isQueryParam}}{{^isBodyParam}}{{^legacyDates}}@Param("{{paramName}}") {{/legacyDates}}{{#legacyDates}}@Param(value="{{paramName}}", expander=ParamExpander.class) {{/legacyDates}}{{/isBodyParam}}{{{dataType}}} {{paramName}}, {{/isQueryParam}}{{/allParams}}@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>{{operationId}}</code> method in a fluent style.
    */

modules/openapi-generator/src/main/resources/Java/libraries/feign/model/HttpResponse.mustache

@@ -0,0 +1,24 @@
+package {{modelPackage}};
+
+import java.util.Map;
+import java.util.Collection;
+
+public class HttpResponse<T>{
+
+  private Map<String, Collection<String>> headers;
+
+  private T body;
+
+  public HttpResponse(Map<String, Collection<String>> headers, T body) {
+    this.headers = headers;
+    this.body = body;
+  }
+
+  public T getBody(){
+    return body;
+  }
+
+  public Map<String, Collection<String>> getHeaders(){
+    return headers;
+  }
+}

samples/client/petstore/java/feign-no-nullable/.openapi-generator/FILES

@@ -16,6 +16,7 @@ src/main/AndroidManifest.xml
 src/main/java/org/openapitools/client/ApiClient.java
 src/main/java/org/openapitools/client/CustomInstantDeserializer.java
 src/main/java/org/openapitools/client/EncodingUtils.java
+src/main/java/org/openapitools/client/JacksonResponseDecoder.java
 src/main/java/org/openapitools/client/ParamExpander.java
 src/main/java/org/openapitools/client/RFC3339DateFormat.java
 src/main/java/org/openapitools/client/ServerConfiguration.java
@@ -64,6 +65,7 @@ src/main/java/org/openapitools/client/model/EnumTest.java
 src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
 src/main/java/org/openapitools/client/model/FormatTest.java
 src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+src/main/java/org/openapitools/client/model/HttpResponse.java
 src/main/java/org/openapitools/client/model/MapTest.java
 src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
 src/main/java/org/openapitools/client/model/Model200Response.java

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/ApiClient.java

@@ -22,6 +22,7 @@ import feign.slf4j.Slf4jLogger;
 import org.openapitools.client.auth.HttpBasicAuth;
 import org.openapitools.client.auth.HttpBearerAuth;
 import org.openapitools.client.auth.ApiKeyAuth;
+import org.openapitools.client.JacksonResponseDecoder;
 
 import org.openapitools.client.auth.ApiErrorDecoder;
 import org.openapitools.client.auth.OAuth;
@@ -48,7 +49,7 @@ public class ApiClient {
     feignBuilder = Feign.builder()
                 .client(new OkHttpClient())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
-                .decoder(new JacksonDecoder(objectMapper))
+                .decoder(new JacksonResponseDecoder(objectMapper))
                 .errorDecoder(new ApiErrorDecoder())
                 .retryer(new Retryer.Default(0, 0, 2))
                 .logger(new Slf4jLogger());

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/JacksonResponseDecoder.java

@@ -0,0 +1,38 @@
+package org.openapitools.client;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.Response;
+import feign.Types;
+import feign.jackson.JacksonDecoder;
+
+import java.io.IOException;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+import org.openapitools.client.model.HttpResponse;
+
+public class JacksonResponseDecoder extends JacksonDecoder {
+
+    public JacksonResponseDecoder(ObjectMapper mapper) {
+        super(mapper);
+    }
+
+    @Override
+    public Object decode(Response response, Type type) throws IOException {
+    Map<String, Collection<String>> responseHeaders = Collections.unmodifiableMap(response.headers());
+        //Detects if the type is an instance of the parameterized class HttpResponse
+        Type responseBodyType;
+        if (Types.getRawType(type).isAssignableFrom(HttpResponse.class)) {
+            //The HttpResponse class has a single type parameter, the Dto class itself
+            responseBodyType = ((ParameterizedType) type).getActualTypeArguments()[0];
+            Object body = super.decode(response, responseBodyType);
+            return new HttpResponse(responseHeaders, body);
+        } else {
+            //The response is not encapsulated in the HttpResponse, decode the Dto as normal
+            return super.decode(response, type);
+        }
+    }
+}

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Client;
 
@@ -27,4 +28,20 @@ public interface AnotherFakeApi extends ApiClient.Api {
     "Accept: application/json",
   })
   Client call123testSpecialTags(Client body);
+
+  /**
+   * To test special tags
+   * Similar to <code>call123testSpecialTags</code> but it also returns the http response headers .
+   * To test special tags and operation ID starting with number
+   * @param body client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /another-fake/dummy")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> call123testSpecialTagsWithHttpInfo(Client body);
+
+
 }

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import java.math.BigDecimal;
 import org.openapitools.client.model.Client;
@@ -35,6 +36,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void createXmlItem(XmlItem xmlItem);
 
+  /**
+   * creates an XmlItem
+   * Similar to <code>createXmlItem</code> but it also returns the http response headers .
+   * this route creates an XmlItem
+   * @param xmlItem XmlItem Body (required)
+   */
+  @RequestLine("POST /fake/create_xml_item")
+  @Headers({
+    "Content-Type: application/xml",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createXmlItemWithHttpInfo(XmlItem xmlItem);
+
+
+
   /**
    * 
    * Test serialization of outer boolean types
@@ -48,6 +64,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   Boolean fakeOuterBooleanSerialize(Boolean body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterBooleanSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer boolean types
+   * @param body Input boolean as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/boolean")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: */*",
+  })
+  HttpResponse<Boolean> fakeOuterBooleanSerializeWithHttpInfo(Boolean body);
+
+
+
   /**
    * 
    * Test serialization of object with outer number type
@@ -61,6 +93,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   OuterComposite fakeOuterCompositeSerialize(OuterComposite body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterCompositeSerialize</code> but it also returns the http response headers .
+   * Test serialization of object with outer number type
+   * @param body Input composite as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/composite")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: */*",
+  })
+  HttpResponse<OuterComposite> fakeOuterCompositeSerializeWithHttpInfo(OuterComposite body);
+
+
+
   /**
    * 
    * Test serialization of outer number types
@@ -74,6 +122,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   BigDecimal fakeOuterNumberSerialize(BigDecimal body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterNumberSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer number types
+   * @param body Input number as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/number")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: */*",
+  })
+  HttpResponse<BigDecimal> fakeOuterNumberSerializeWithHttpInfo(BigDecimal body);
+
+
+
   /**
    * 
    * Test serialization of outer string types
@@ -87,6 +151,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   String fakeOuterStringSerialize(String body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterStringSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer string types
+   * @param body Input string as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/string")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: */*",
+  })
+  HttpResponse<String> fakeOuterStringSerializeWithHttpInfo(String body);
+
+
+
   /**
    * 
    * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
@@ -99,6 +179,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testBodyWithFileSchema(FileSchemaTestClass body);
 
+  /**
+   * 
+   * Similar to <code>testBodyWithFileSchema</code> but it also returns the http response headers .
+   * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
+   * @param body  (required)
+   */
+  @RequestLine("PUT /fake/body-with-file-schema")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testBodyWithFileSchemaWithHttpInfo(FileSchemaTestClass body);
+
+
+
   /**
    * 
    * 
@@ -112,6 +207,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testBodyWithQueryParams(@Param("query") String query, User body);
 
+  /**
+   * 
+   * Similar to <code>testBodyWithQueryParams</code> but it also returns the http response headers .
+   * 
+   * @param query  (required)
+   * @param body  (required)
+   */
+  @RequestLine("PUT /fake/body-with-query-params?query={query}")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testBodyWithQueryParamsWithHttpInfo(@Param("query") String query, User body);
+
+
   /**
    * 
    * 
@@ -135,6 +245,26 @@ public interface FakeApi extends ApiClient.Api {
   void testBodyWithQueryParams(User body, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * 
+  * 
+  * Note, this is equivalent to the other <code>testBodyWithQueryParams</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param body  (required)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>query -  (required)</li>
+      *   </ul>
+      */
+      @RequestLine("PUT /fake/body-with-query-params?query={query}")
+      @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+      })
+   HttpResponse<Void> testBodyWithQueryParamsWithHttpInfo(User body, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testBodyWithQueryParams</code> method in a fluent style.
    */
@@ -158,6 +288,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   Client testClientModel(Client body);
 
+  /**
+   * To test \&quot;client\&quot; model
+   * Similar to <code>testClientModel</code> but it also returns the http response headers .
+   * To test \&quot;client\&quot; model
+   * @param body client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /fake")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> testClientModelWithHttpInfo(Client body);
+
+
+
   /**
    * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
    * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
@@ -183,6 +329,34 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testEndpointParameters(@Param("number") BigDecimal number, @Param("_double") Double _double, @Param("patternWithoutDelimiter") String patternWithoutDelimiter, @Param("_byte") byte[] _byte, @Param("integer") Integer integer, @Param("int32") Integer int32, @Param("int64") Long int64, @Param("_float") Float _float, @Param("string") String string, @Param("binary") File binary, @Param("date") LocalDate date, @Param("dateTime") OffsetDateTime dateTime, @Param("password") String password, @Param("paramCallback") String paramCallback);
 
+  /**
+   * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
+   * Similar to <code>testEndpointParameters</code> but it also returns the http response headers .
+   * Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
+   * @param number None (required)
+   * @param _double None (required)
+   * @param patternWithoutDelimiter None (required)
+   * @param _byte None (required)
+   * @param integer None (optional)
+   * @param int32 None (optional)
+   * @param int64 None (optional)
+   * @param _float None (optional)
+   * @param string None (optional)
+   * @param binary None (optional)
+   * @param date None (optional)
+   * @param dateTime None (optional)
+   * @param password None (optional)
+   * @param paramCallback None (optional)
+   */
+  @RequestLine("POST /fake")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testEndpointParametersWithHttpInfo(@Param("number") BigDecimal number, @Param("_double") Double _double, @Param("patternWithoutDelimiter") String patternWithoutDelimiter, @Param("_byte") byte[] _byte, @Param("integer") Integer integer, @Param("int32") Integer int32, @Param("int64") Long int64, @Param("_float") Float _float, @Param("string") String string, @Param("binary") File binary, @Param("date") LocalDate date, @Param("dateTime") OffsetDateTime dateTime, @Param("password") String password, @Param("paramCallback") String paramCallback);
+
+
+
   /**
    * To test enum parameters
    * To test enum parameters
@@ -205,6 +379,30 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testEnumParameters(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumQueryStringArray") List<String> enumQueryStringArray, @Param("enumQueryString") String enumQueryString, @Param("enumQueryInteger") Integer enumQueryInteger, @Param("enumQueryDouble") Double enumQueryDouble, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString);
 
+  /**
+   * To test enum parameters
+   * Similar to <code>testEnumParameters</code> but it also returns the http response headers .
+   * To test enum parameters
+   * @param enumHeaderStringArray Header parameter enum test (string array) (optional)
+   * @param enumHeaderString Header parameter enum test (string) (optional, default to -efg)
+   * @param enumQueryStringArray Query parameter enum test (string array) (optional)
+   * @param enumQueryString Query parameter enum test (string) (optional, default to -efg)
+   * @param enumQueryInteger Query parameter enum test (double) (optional)
+   * @param enumQueryDouble Query parameter enum test (double) (optional)
+   * @param enumFormStringArray Form parameter enum test (string array) (optional)
+   * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
+   */
+  @RequestLine("GET /fake?enum_query_string_array={enumQueryStringArray}&enum_query_string={enumQueryString}&enum_query_integer={enumQueryInteger}&enum_query_double={enumQueryDouble}")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+    "enum_header_string_array: {enumHeaderStringArray}",
+    
+    "enum_header_string: {enumHeaderString}"
+  })
+  HttpResponse<Void> testEnumParametersWithHttpInfo(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumQueryStringArray") List<String> enumQueryStringArray, @Param("enumQueryString") String enumQueryString, @Param("enumQueryInteger") Integer enumQueryInteger, @Param("enumQueryDouble") Double enumQueryDouble, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString);
+
+
   /**
    * To test enum parameters
    * To test enum parameters
@@ -237,6 +435,35 @@ public interface FakeApi extends ApiClient.Api {
   void testEnumParameters(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * To test enum parameters
+  * To test enum parameters
+  * Note, this is equivalent to the other <code>testEnumParameters</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param enumHeaderStringArray Header parameter enum test (string array) (optional)
+              * @param enumHeaderString Header parameter enum test (string) (optional, default to -efg)
+              * @param enumFormStringArray Form parameter enum test (string array) (optional)
+              * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>enumQueryStringArray - Query parameter enum test (string array) (optional)</li>
+          *   <li>enumQueryString - Query parameter enum test (string) (optional, default to -efg)</li>
+          *   <li>enumQueryInteger - Query parameter enum test (double) (optional)</li>
+          *   <li>enumQueryDouble - Query parameter enum test (double) (optional)</li>
+      *   </ul>
+      */
+      @RequestLine("GET /fake?enum_query_string_array={enumQueryStringArray}&enum_query_string={enumQueryString}&enum_query_integer={enumQueryInteger}&enum_query_double={enumQueryDouble}")
+      @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+          "enum_header_string_array: {enumHeaderStringArray}",
+      
+          "enum_header_string: {enumHeaderString}"
+      })
+   HttpResponse<Void> testEnumParametersWithHttpInfo(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testEnumParameters</code> method in a fluent style.
    */
@@ -278,6 +505,27 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testGroupParameters(@Param("requiredStringGroup") Integer requiredStringGroup, @Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("requiredInt64Group") Long requiredInt64Group, @Param("stringGroup") Integer stringGroup, @Param("booleanGroup") Boolean booleanGroup, @Param("int64Group") Long int64Group);
 
+  /**
+   * Fake endpoint to test group parameters (optional)
+   * Similar to <code>testGroupParameters</code> but it also returns the http response headers .
+   * Fake endpoint to test group parameters (optional)
+   * @param requiredStringGroup Required String in group parameters (required)
+   * @param requiredBooleanGroup Required Boolean in group parameters (required)
+   * @param requiredInt64Group Required Integer in group parameters (required)
+   * @param stringGroup String in group parameters (optional)
+   * @param booleanGroup Boolean in group parameters (optional)
+   * @param int64Group Integer in group parameters (optional)
+   */
+  @RequestLine("DELETE /fake?required_string_group={requiredStringGroup}&required_int64_group={requiredInt64Group}&string_group={stringGroup}&int64_group={int64Group}")
+  @Headers({
+    "Accept: application/json",
+    "required_boolean_group: {requiredBooleanGroup}",
+    
+    "boolean_group: {booleanGroup}"
+  })
+  HttpResponse<Void> testGroupParametersWithHttpInfo(@Param("requiredStringGroup") Integer requiredStringGroup, @Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("requiredInt64Group") Long requiredInt64Group, @Param("stringGroup") Integer stringGroup, @Param("booleanGroup") Boolean booleanGroup, @Param("int64Group") Long int64Group);
+
+
   /**
    * Fake endpoint to test group parameters (optional)
    * Fake endpoint to test group parameters (optional)
@@ -307,6 +555,32 @@ public interface FakeApi extends ApiClient.Api {
   void testGroupParameters(@Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("booleanGroup") Boolean booleanGroup, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Fake endpoint to test group parameters (optional)
+  * Fake endpoint to test group parameters (optional)
+  * Note, this is equivalent to the other <code>testGroupParameters</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param requiredBooleanGroup Required Boolean in group parameters (required)
+              * @param booleanGroup Boolean in group parameters (optional)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>requiredStringGroup - Required String in group parameters (required)</li>
+          *   <li>requiredInt64Group - Required Integer in group parameters (required)</li>
+          *   <li>stringGroup - String in group parameters (optional)</li>
+          *   <li>int64Group - Integer in group parameters (optional)</li>
+      *   </ul>
+      */
+      @RequestLine("DELETE /fake?required_string_group={requiredStringGroup}&required_int64_group={requiredInt64Group}&string_group={stringGroup}&int64_group={int64Group}")
+      @Headers({
+    "Accept: application/json",
+          "required_boolean_group: {requiredBooleanGroup}",
+      
+          "boolean_group: {booleanGroup}"
+      })
+   HttpResponse<Void> testGroupParametersWithHttpInfo(@Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("booleanGroup") Boolean booleanGroup, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testGroupParameters</code> method in a fluent style.
    */
@@ -341,6 +615,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testInlineAdditionalProperties(Map<String, String> param);
 
+  /**
+   * test inline additionalProperties
+   * Similar to <code>testInlineAdditionalProperties</code> but it also returns the http response headers .
+   * 
+   * @param param request body (required)
+   */
+  @RequestLine("POST /fake/inline-additionalProperties")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testInlineAdditionalPropertiesWithHttpInfo(Map<String, String> param);
+
+
+
   /**
    * test json serialization of form data
    * 
@@ -354,6 +643,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testJsonFormData(@Param("param") String param, @Param("param2") String param2);
 
+  /**
+   * test json serialization of form data
+   * Similar to <code>testJsonFormData</code> but it also returns the http response headers .
+   * 
+   * @param param field1 (required)
+   * @param param2 field2 (required)
+   */
+  @RequestLine("GET /fake/jsonFormData")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testJsonFormDataWithHttpInfo(@Param("param") String param, @Param("param2") String param2);
+
+
+
   /**
    * 
    * To test the collection format in query parameters
@@ -369,6 +674,23 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testQueryParameterCollectionFormat(@Param("pipe") List<String> pipe, @Param("ioutil") List<String> ioutil, @Param("http") List<String> http, @Param("url") List<String> url, @Param("context") List<String> context);
 
+  /**
+   * 
+   * Similar to <code>testQueryParameterCollectionFormat</code> but it also returns the http response headers .
+   * To test the collection format in query parameters
+   * @param pipe  (required)
+   * @param ioutil  (required)
+   * @param http  (required)
+   * @param url  (required)
+   * @param context  (required)
+   */
+  @RequestLine("PUT /fake/test-query-parameters?pipe={pipe}&ioutil={ioutil}&http={http}&url={url}&context={context}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(@Param("pipe") List<String> pipe, @Param("ioutil") List<String> ioutil, @Param("http") List<String> http, @Param("url") List<String> url, @Param("context") List<String> context);
+
+
   /**
    * 
    * To test the collection format in query parameters
@@ -394,6 +716,28 @@ public interface FakeApi extends ApiClient.Api {
   void testQueryParameterCollectionFormat(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * 
+  * To test the collection format in query parameters
+  * Note, this is equivalent to the other <code>testQueryParameterCollectionFormat</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>pipe -  (required)</li>
+          *   <li>ioutil -  (required)</li>
+          *   <li>http -  (required)</li>
+          *   <li>url -  (required)</li>
+          *   <li>context -  (required)</li>
+      *   </ul>
+      */
+      @RequestLine("PUT /fake/test-query-parameters?pipe={pipe}&ioutil={ioutil}&http={http}&url={url}&context={context}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testQueryParameterCollectionFormat</code> method in a fluent style.
    */

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Client;
 
@@ -27,4 +28,20 @@ public interface FakeClassnameTags123Api extends ApiClient.Api {
     "Accept: application/json",
   })
   Client testClassname(Client body);
+
+  /**
+   * To test class name in snake case
+   * Similar to <code>testClassname</code> but it also returns the http response headers .
+   * To test class name in snake case
+   * @param body client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /fake_classname_test")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> testClassnameWithHttpInfo(Client body);
+
+
 }

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/PetApi.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import java.io.File;
 import org.openapitools.client.model.ModelApiResponse;
@@ -30,6 +31,21 @@ public interface PetApi extends ApiClient.Api {
   })
   void addPet(Pet body);
 
+  /**
+   * Add a new pet to the store
+   * Similar to <code>addPet</code> but it also returns the http response headers .
+   * 
+   * @param body Pet object that needs to be added to the store (required)
+   */
+  @RequestLine("POST /pet")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> addPetWithHttpInfo(Pet body);
+
+
+
   /**
    * Deletes a pet
    * 
@@ -43,6 +59,22 @@ public interface PetApi extends ApiClient.Api {
   })
   void deletePet(@Param("petId") Long petId, @Param("apiKey") String apiKey);
 
+  /**
+   * Deletes a pet
+   * Similar to <code>deletePet</code> but it also returns the http response headers .
+   * 
+   * @param petId Pet id to delete (required)
+   * @param apiKey  (optional)
+   */
+  @RequestLine("DELETE /pet/{petId}")
+  @Headers({
+    "Accept: application/json",
+    "api_key: {apiKey}"
+  })
+  HttpResponse<Void> deletePetWithHttpInfo(@Param("petId") Long petId, @Param("apiKey") String apiKey);
+
+
+
   /**
    * Finds Pets by status
    * Multiple status values can be provided with comma separated strings
@@ -55,6 +87,20 @@ public interface PetApi extends ApiClient.Api {
   })
   List<Pet> findPetsByStatus(@Param("status") List<String> status);
 
+  /**
+   * Finds Pets by status
+   * Similar to <code>findPetsByStatus</code> but it also returns the http response headers .
+   * Multiple status values can be provided with comma separated strings
+   * @param status Status values that need to be considered for filter (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /pet/findByStatus?status={status}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<List<Pet>> findPetsByStatusWithHttpInfo(@Param("status") List<String> status);
+
+
   /**
    * Finds Pets by status
    * Multiple status values can be provided with comma separated strings
@@ -77,6 +123,25 @@ public interface PetApi extends ApiClient.Api {
   List<Pet> findPetsByStatus(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Finds Pets by status
+  * Multiple status values can be provided with comma separated strings
+  * Note, this is equivalent to the other <code>findPetsByStatus</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>status - Status values that need to be considered for filter (required)</li>
+      *   </ul>
+          * @return List&lt;Pet&gt;
+      */
+      @RequestLine("GET /pet/findByStatus?status={status}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<List<Pet>> findPetsByStatusWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>findPetsByStatus</code> method in a fluent style.
    */
@@ -101,6 +166,22 @@ public interface PetApi extends ApiClient.Api {
   })
   Set<Pet> findPetsByTags(@Param("tags") Set<String> tags);
 
+  /**
+   * Finds Pets by tags
+   * Similar to <code>findPetsByTags</code> but it also returns the http response headers .
+   * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+   * @param tags Tags to filter by (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   * @deprecated
+   */
+  @Deprecated
+  @RequestLine("GET /pet/findByTags?tags={tags}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Set<Pet>> findPetsByTagsWithHttpInfo(@Param("tags") Set<String> tags);
+
+
   /**
    * Finds Pets by tags
    * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
@@ -125,6 +206,27 @@ public interface PetApi extends ApiClient.Api {
   Set<Pet> findPetsByTags(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Finds Pets by tags
+  * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+  * Note, this is equivalent to the other <code>findPetsByTags</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>tags - Tags to filter by (required)</li>
+      *   </ul>
+          * @return Set&lt;Pet&gt;
+          * @deprecated
+      */
+          @Deprecated
+      @RequestLine("GET /pet/findByTags?tags={tags}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<Set<Pet>> findPetsByTagsWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>findPetsByTags</code> method in a fluent style.
    */
@@ -147,6 +249,21 @@ public interface PetApi extends ApiClient.Api {
   })
   Pet getPetById(@Param("petId") Long petId);
 
+  /**
+   * Find pet by ID
+   * Similar to <code>getPetById</code> but it also returns the http response headers .
+   * Returns a single pet
+   * @param petId ID of pet to return (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /pet/{petId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Pet> getPetByIdWithHttpInfo(@Param("petId") Long petId);
+
+
+
   /**
    * Update an existing pet
    * 
@@ -159,6 +276,21 @@ public interface PetApi extends ApiClient.Api {
   })
   void updatePet(Pet body);
 
+  /**
+   * Update an existing pet
+   * Similar to <code>updatePet</code> but it also returns the http response headers .
+   * 
+   * @param body Pet object that needs to be added to the store (required)
+   */
+  @RequestLine("PUT /pet")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updatePetWithHttpInfo(Pet body);
+
+
+
   /**
    * Updates a pet in the store with form data
    * 
@@ -173,6 +305,23 @@ public interface PetApi extends ApiClient.Api {
   })
   void updatePetWithForm(@Param("petId") Long petId, @Param("name") String name, @Param("status") String status);
 
+  /**
+   * Updates a pet in the store with form data
+   * Similar to <code>updatePetWithForm</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet that needs to be updated (required)
+   * @param name Updated name of the pet (optional)
+   * @param status Updated status of the pet (optional)
+   */
+  @RequestLine("POST /pet/{petId}")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updatePetWithFormWithHttpInfo(@Param("petId") Long petId, @Param("name") String name, @Param("status") String status);
+
+
+
   /**
    * uploads an image
    * 
@@ -188,6 +337,24 @@ public interface PetApi extends ApiClient.Api {
   })
   ModelApiResponse uploadFile(@Param("petId") Long petId, @Param("additionalMetadata") String additionalMetadata, @Param("file") File file);
 
+  /**
+   * uploads an image
+   * Similar to <code>uploadFile</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet to update (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @param file file to upload (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /pet/{petId}/uploadImage")
+  @Headers({
+    "Content-Type: multipart/form-data",
+    "Accept: application/json",
+  })
+  HttpResponse<ModelApiResponse> uploadFileWithHttpInfo(@Param("petId") Long petId, @Param("additionalMetadata") String additionalMetadata, @Param("file") File file);
+
+
+
   /**
    * uploads an image (required)
    * 
@@ -202,4 +369,22 @@ public interface PetApi extends ApiClient.Api {
     "Accept: application/json",
   })
   ModelApiResponse uploadFileWithRequiredFile(@Param("petId") Long petId, @Param("requiredFile") File requiredFile, @Param("additionalMetadata") String additionalMetadata);
+
+  /**
+   * uploads an image (required)
+   * Similar to <code>uploadFileWithRequiredFile</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet to update (required)
+   * @param requiredFile file to upload (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/{petId}/uploadImageWithRequiredFile")
+  @Headers({
+    "Content-Type: multipart/form-data",
+    "Accept: application/json",
+  })
+  HttpResponse<ModelApiResponse> uploadFileWithRequiredFileWithHttpInfo(@Param("petId") Long petId, @Param("requiredFile") File requiredFile, @Param("additionalMetadata") String additionalMetadata);
+
+
 }

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Order;
 
@@ -26,6 +27,20 @@ public interface StoreApi extends ApiClient.Api {
   })
   void deleteOrder(@Param("orderId") String orderId);
 
+  /**
+   * Delete purchase order by ID
+   * Similar to <code>deleteOrder</code> but it also returns the http response headers .
+   * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+   * @param orderId ID of the order that needs to be deleted (required)
+   */
+  @RequestLine("DELETE /store/order/{orderId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> deleteOrderWithHttpInfo(@Param("orderId") String orderId);
+
+
+
   /**
    * Returns pet inventories by status
    * Returns a map of status codes to quantities
@@ -37,6 +52,20 @@ public interface StoreApi extends ApiClient.Api {
   })
   Map<String, Integer> getInventory();
 
+  /**
+   * Returns pet inventories by status
+   * Similar to <code>getInventory</code> but it also returns the http response headers .
+   * Returns a map of status codes to quantities
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /store/inventory")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Map<String, Integer>> getInventoryWithHttpInfo();
+
+
+
   /**
    * Find purchase order by ID
    * For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
@@ -49,6 +78,21 @@ public interface StoreApi extends ApiClient.Api {
   })
   Order getOrderById(@Param("orderId") Long orderId);
 
+  /**
+   * Find purchase order by ID
+   * Similar to <code>getOrderById</code> but it also returns the http response headers .
+   * For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+   * @param orderId ID of pet that needs to be fetched (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /store/order/{orderId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Order> getOrderByIdWithHttpInfo(@Param("orderId") Long orderId);
+
+
+
   /**
    * Place an order for a pet
    * 
@@ -61,4 +105,20 @@ public interface StoreApi extends ApiClient.Api {
     "Accept: application/json",
   })
   Order placeOrder(Order body);
+
+  /**
+   * Place an order for a pet
+   * Similar to <code>placeOrder</code> but it also returns the http response headers .
+   * 
+   * @param body order placed for purchasing the pet (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /store/order")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: application/json",
+  })
+  HttpResponse<Order> placeOrderWithHttpInfo(Order body);
+
+
 }

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/api/UserApi.java

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.User;
 
@@ -27,6 +28,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUser(User body);
 
+  /**
+   * Create user
+   * Similar to <code>createUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param body Created user object (required)
+   */
+  @RequestLine("POST /user")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUserWithHttpInfo(User body);
+
+
+
   /**
    * Creates list of users with given input array
    * 
@@ -39,6 +55,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUsersWithArrayInput(List<User> body);
 
+  /**
+   * Creates list of users with given input array
+   * Similar to <code>createUsersWithArrayInput</code> but it also returns the http response headers .
+   * 
+   * @param body List of user object (required)
+   */
+  @RequestLine("POST /user/createWithArray")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> body);
+
+
+
   /**
    * Creates list of users with given input array
    * 
@@ -51,6 +82,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUsersWithListInput(List<User> body);
 
+  /**
+   * Creates list of users with given input array
+   * Similar to <code>createUsersWithListInput</code> but it also returns the http response headers .
+   * 
+   * @param body List of user object (required)
+   */
+  @RequestLine("POST /user/createWithList")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUsersWithListInputWithHttpInfo(List<User> body);
+
+
+
   /**
    * Delete user
    * This can only be done by the logged in user.
@@ -62,6 +108,20 @@ public interface UserApi extends ApiClient.Api {
   })
   void deleteUser(@Param("username") String username);
 
+  /**
+   * Delete user
+   * Similar to <code>deleteUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param username The name that needs to be deleted (required)
+   */
+  @RequestLine("DELETE /user/{username}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> deleteUserWithHttpInfo(@Param("username") String username);
+
+
+
   /**
    * Get user by user name
    * 
@@ -74,6 +134,21 @@ public interface UserApi extends ApiClient.Api {
   })
   User getUserByName(@Param("username") String username);
 
+  /**
+   * Get user by user name
+   * Similar to <code>getUserByName</code> but it also returns the http response headers .
+   * 
+   * @param username The name that needs to be fetched. Use user1 for testing. (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /user/{username}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<User> getUserByNameWithHttpInfo(@Param("username") String username);
+
+
+
   /**
    * Logs user into the system
    * 
@@ -87,6 +162,21 @@ public interface UserApi extends ApiClient.Api {
   })
   String loginUser(@Param("username") String username, @Param("password") String password);
 
+  /**
+   * Logs user into the system
+   * Similar to <code>loginUser</code> but it also returns the http response headers .
+   * 
+   * @param username The user name for login (required)
+   * @param password The password for login in clear text (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /user/login?username={username}&password={password}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<String> loginUserWithHttpInfo(@Param("username") String username, @Param("password") String password);
+
+
   /**
    * Logs user into the system
    * 
@@ -110,6 +200,26 @@ public interface UserApi extends ApiClient.Api {
   String loginUser(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Logs user into the system
+  * 
+  * Note, this is equivalent to the other <code>loginUser</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>username - The user name for login (required)</li>
+          *   <li>password - The password for login in clear text (required)</li>
+      *   </ul>
+          * @return String
+      */
+      @RequestLine("GET /user/login?username={username}&password={password}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<String> loginUserWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>loginUser</code> method in a fluent style.
    */
@@ -134,6 +244,19 @@ public interface UserApi extends ApiClient.Api {
   })
   void logoutUser();
 
+  /**
+   * Logs out current logged in user session
+   * Similar to <code>logoutUser</code> but it also returns the http response headers .
+   * 
+   */
+  @RequestLine("GET /user/logout")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> logoutUserWithHttpInfo();
+
+
+
   /**
    * Updated user
    * This can only be done by the logged in user.
@@ -146,4 +269,20 @@ public interface UserApi extends ApiClient.Api {
     "Accept: application/json",
   })
   void updateUser(@Param("username") String username, User body);
+
+  /**
+   * Updated user
+   * Similar to <code>updateUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param username name that need to be deleted (required)
+   * @param body Updated user object (required)
+   */
+  @RequestLine("PUT /user/{username}")
+  @Headers({
+    "Content-Type: */*",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updateUserWithHttpInfo(@Param("username") String username, User body);
+
+
 }

samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/HttpResponse.java

@@ -0,0 +1,24 @@
+package org.openapitools.client.model;
+
+import java.util.Map;
+import java.util.Collection;
+
+public class HttpResponse<T>{
+
+  private Map<String, Collection<String>> headers;
+
+  private T body;
+
+  public HttpResponse(Map<String, Collection<String>> headers, T body) {
+    this.headers = headers;
+    this.body = body;
+  }
+
+  public T getBody(){
+    return body;
+  }
+
+  public Map<String, Collection<String>> getHeaders(){
+    return headers;
+  }
+}

samples/client/petstore/java/feign/.openapi-generator/FILES

@@ -16,6 +16,7 @@ src/main/AndroidManifest.xml
 src/main/java/org/openapitools/client/ApiClient.java
 src/main/java/org/openapitools/client/CustomInstantDeserializer.java
 src/main/java/org/openapitools/client/EncodingUtils.java
+src/main/java/org/openapitools/client/JacksonResponseDecoder.java
 src/main/java/org/openapitools/client/ParamExpander.java
 src/main/java/org/openapitools/client/RFC3339DateFormat.java
 src/main/java/org/openapitools/client/ServerConfiguration.java
@@ -59,6 +60,7 @@ src/main/java/org/openapitools/client/model/Foo.java
 src/main/java/org/openapitools/client/model/FormatTest.java
 src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
 src/main/java/org/openapitools/client/model/HealthCheckResult.java
+src/main/java/org/openapitools/client/model/HttpResponse.java
 src/main/java/org/openapitools/client/model/InlineResponseDefault.java
 src/main/java/org/openapitools/client/model/MapTest.java
 src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java

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

@@ -23,6 +23,7 @@ import feign.slf4j.Slf4jLogger;
 import org.openapitools.client.auth.HttpBasicAuth;
 import org.openapitools.client.auth.HttpBearerAuth;
 import org.openapitools.client.auth.ApiKeyAuth;
+import org.openapitools.client.JacksonResponseDecoder;
 
 import org.openapitools.client.auth.ApiErrorDecoder;
 import org.openapitools.client.auth.OAuth;
@@ -49,7 +50,7 @@ public class ApiClient {
     feignBuilder = Feign.builder()
                 .client(new OkHttpClient())
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
-                .decoder(new JacksonDecoder(objectMapper))
+                .decoder(new JacksonResponseDecoder(objectMapper))
                 .errorDecoder(new ApiErrorDecoder())
                 .retryer(new Retryer.Default(0, 0, 2))
                 .logger(new Slf4jLogger());

samples/client/petstore/java/feign/src/main/java/org/openapitools/client/JacksonResponseDecoder.java

@@ -0,0 +1,38 @@
+package org.openapitools.client;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import feign.Response;
+import feign.Types;
+import feign.jackson.JacksonDecoder;
+
+import java.io.IOException;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+import org.openapitools.client.model.HttpResponse;
+
+public class JacksonResponseDecoder extends JacksonDecoder {
+
+    public JacksonResponseDecoder(ObjectMapper mapper) {
+        super(mapper);
+    }
+
+    @Override
+    public Object decode(Response response, Type type) throws IOException {
+    Map<String, Collection<String>> responseHeaders = Collections.unmodifiableMap(response.headers());
+        //Detects if the type is an instance of the parameterized class HttpResponse
+        Type responseBodyType;
+        if (Types.getRawType(type).isAssignableFrom(HttpResponse.class)) {
+            //The HttpResponse class has a single type parameter, the Dto class itself
+            responseBodyType = ((ParameterizedType) type).getActualTypeArguments()[0];
+            Object body = super.decode(response, responseBodyType);
+            return new HttpResponse(responseHeaders, body);
+        } else {
+            //The response is not encapsulated in the HttpResponse, decode the Dto as normal
+            return super.decode(response, type);
+        }
+    }
+}

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Client;
 
@@ -27,4 +28,20 @@ public interface AnotherFakeApi extends ApiClient.Api {
     "Accept: application/json",
   })
   Client call123testSpecialTags(Client client);
+
+  /**
+   * To test special tags
+   * Similar to <code>call123testSpecialTags</code> but it also returns the http response headers .
+   * To test special tags and operation ID starting with number
+   * @param client client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /another-fake/dummy")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> call123testSpecialTagsWithHttpInfo(Client client);
+
+
 }

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.InlineResponseDefault;
 
@@ -25,4 +26,18 @@ public interface DefaultApi extends ApiClient.Api {
     "Accept: application/json",
   })
   InlineResponseDefault fooGet();
+
+  /**
+   * 
+   * Similar to <code>fooGet</code> but it also returns the http response headers .
+   * 
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /foo")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<InlineResponseDefault> fooGetWithHttpInfo();
+
+
 }

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import java.math.BigDecimal;
 import org.openapitools.client.model.Client;
@@ -36,6 +37,20 @@ public interface FakeApi extends ApiClient.Api {
   })
   HealthCheckResult fakeHealthGet();
 
+  /**
+   * Health check endpoint
+   * Similar to <code>fakeHealthGet</code> but it also returns the http response headers .
+   * 
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /fake/health")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<HealthCheckResult> fakeHealthGetWithHttpInfo();
+
+
+
   /**
    * test http signature authentication
    * 
@@ -51,6 +66,23 @@ public interface FakeApi extends ApiClient.Api {
   })
   void fakeHttpSignatureTest(Pet pet, @Param("query1") String query1, @Param("header1") String header1);
 
+  /**
+   * test http signature authentication
+   * Similar to <code>fakeHttpSignatureTest</code> but it also returns the http response headers .
+   * 
+   * @param pet Pet object that needs to be added to the store (required)
+   * @param query1 query parameter (optional)
+   * @param header1 header parameter (optional)
+   */
+  @RequestLine("GET /fake/http-signature-test?query_1={query1}")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+    "header_1: {header1}"
+  })
+  HttpResponse<Void> fakeHttpSignatureTestWithHttpInfo(Pet pet, @Param("query1") String query1, @Param("header1") String header1);
+
+
   /**
    * test http signature authentication
    * 
@@ -76,6 +108,28 @@ public interface FakeApi extends ApiClient.Api {
   void fakeHttpSignatureTest(Pet pet, @Param("header1") String header1, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * test http signature authentication
+  * 
+  * Note, this is equivalent to the other <code>fakeHttpSignatureTest</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param pet Pet object that needs to be added to the store (required)
+              * @param header1 header parameter (optional)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>query1 - query parameter (optional)</li>
+      *   </ul>
+      */
+      @RequestLine("GET /fake/http-signature-test?query_1={query1}")
+      @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+          "header_1: {header1}"
+      })
+   HttpResponse<Void> fakeHttpSignatureTestWithHttpInfo(Pet pet, @Param("header1") String header1, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>fakeHttpSignatureTest</code> method in a fluent style.
    */
@@ -99,6 +153,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   Boolean fakeOuterBooleanSerialize(Boolean body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterBooleanSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer boolean types
+   * @param body Input boolean as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/boolean")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: */*",
+  })
+  HttpResponse<Boolean> fakeOuterBooleanSerializeWithHttpInfo(Boolean body);
+
+
+
   /**
    * 
    * Test serialization of object with outer number type
@@ -112,6 +182,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   OuterComposite fakeOuterCompositeSerialize(OuterComposite outerComposite);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterCompositeSerialize</code> but it also returns the http response headers .
+   * Test serialization of object with outer number type
+   * @param outerComposite Input composite as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/composite")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: */*",
+  })
+  HttpResponse<OuterComposite> fakeOuterCompositeSerializeWithHttpInfo(OuterComposite outerComposite);
+
+
+
   /**
    * 
    * Test serialization of outer number types
@@ -125,6 +211,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   BigDecimal fakeOuterNumberSerialize(BigDecimal body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterNumberSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer number types
+   * @param body Input number as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/number")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: */*",
+  })
+  HttpResponse<BigDecimal> fakeOuterNumberSerializeWithHttpInfo(BigDecimal body);
+
+
+
   /**
    * 
    * Test serialization of outer string types
@@ -138,6 +240,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   String fakeOuterStringSerialize(String body);
 
+  /**
+   * 
+   * Similar to <code>fakeOuterStringSerialize</code> but it also returns the http response headers .
+   * Test serialization of outer string types
+   * @param body Input string as post body (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/outer/string")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: */*",
+  })
+  HttpResponse<String> fakeOuterStringSerializeWithHttpInfo(String body);
+
+
+
   /**
    * 
    * Test serialization of enum (int) properties with examples
@@ -151,6 +269,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   OuterObjectWithEnumProperty fakePropertyEnumIntegerSerialize(OuterObjectWithEnumProperty outerObjectWithEnumProperty);
 
+  /**
+   * 
+   * Similar to <code>fakePropertyEnumIntegerSerialize</code> but it also returns the http response headers .
+   * Test serialization of enum (int) properties with examples
+   * @param outerObjectWithEnumProperty Input enum (int) as post body (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/property/enum-int")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: */*",
+  })
+  HttpResponse<OuterObjectWithEnumProperty> fakePropertyEnumIntegerSerializeWithHttpInfo(OuterObjectWithEnumProperty outerObjectWithEnumProperty);
+
+
+
   /**
    * 
    * For this test, the body has to be a binary file.
@@ -163,6 +297,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testBodyWithBinary(File body);
 
+  /**
+   * 
+   * Similar to <code>testBodyWithBinary</code> but it also returns the http response headers .
+   * For this test, the body has to be a binary file.
+   * @param body image to upload (required)
+   */
+  @RequestLine("PUT /fake/body-with-binary")
+  @Headers({
+    "Content-Type: image/png",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testBodyWithBinaryWithHttpInfo(File body);
+
+
+
   /**
    * 
    * For this test, the body for this request must reference a schema named &#x60;File&#x60;.
@@ -175,6 +324,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testBodyWithFileSchema(FileSchemaTestClass fileSchemaTestClass);
 
+  /**
+   * 
+   * Similar to <code>testBodyWithFileSchema</code> but it also returns the http response headers .
+   * For this test, the body for this request must reference a schema named &#x60;File&#x60;.
+   * @param fileSchemaTestClass  (required)
+   */
+  @RequestLine("PUT /fake/body-with-file-schema")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testBodyWithFileSchemaWithHttpInfo(FileSchemaTestClass fileSchemaTestClass);
+
+
+
   /**
    * 
    * 
@@ -188,6 +352,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testBodyWithQueryParams(@Param("query") String query, User user);
 
+  /**
+   * 
+   * Similar to <code>testBodyWithQueryParams</code> but it also returns the http response headers .
+   * 
+   * @param query  (required)
+   * @param user  (required)
+   */
+  @RequestLine("PUT /fake/body-with-query-params?query={query}")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testBodyWithQueryParamsWithHttpInfo(@Param("query") String query, User user);
+
+
   /**
    * 
    * 
@@ -211,6 +390,26 @@ public interface FakeApi extends ApiClient.Api {
   void testBodyWithQueryParams(User user, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * 
+  * 
+  * Note, this is equivalent to the other <code>testBodyWithQueryParams</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param user  (required)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>query -  (required)</li>
+      *   </ul>
+      */
+      @RequestLine("PUT /fake/body-with-query-params?query={query}")
+      @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+      })
+   HttpResponse<Void> testBodyWithQueryParamsWithHttpInfo(User user, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testBodyWithQueryParams</code> method in a fluent style.
    */
@@ -234,6 +433,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   Client testClientModel(Client client);
 
+  /**
+   * To test \&quot;client\&quot; model
+   * Similar to <code>testClientModel</code> but it also returns the http response headers .
+   * To test \&quot;client\&quot; model
+   * @param client client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /fake")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> testClientModelWithHttpInfo(Client client);
+
+
+
   /**
    * Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
    * Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
@@ -259,6 +474,34 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testEndpointParameters(@Param("number") BigDecimal number, @Param("_double") Double _double, @Param("patternWithoutDelimiter") String patternWithoutDelimiter, @Param("_byte") byte[] _byte, @Param("integer") Integer integer, @Param("int32") Integer int32, @Param("int64") Long int64, @Param("_float") Float _float, @Param("string") String string, @Param("binary") File binary, @Param("date") LocalDate date, @Param("dateTime") OffsetDateTime dateTime, @Param("password") String password, @Param("paramCallback") String paramCallback);
 
+  /**
+   * Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
+   * Similar to <code>testEndpointParameters</code> but it also returns the http response headers .
+   * Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
+   * @param number None (required)
+   * @param _double None (required)
+   * @param patternWithoutDelimiter None (required)
+   * @param _byte None (required)
+   * @param integer None (optional)
+   * @param int32 None (optional)
+   * @param int64 None (optional)
+   * @param _float None (optional)
+   * @param string None (optional)
+   * @param binary None (optional)
+   * @param date None (optional)
+   * @param dateTime None (optional)
+   * @param password None (optional)
+   * @param paramCallback None (optional)
+   */
+  @RequestLine("POST /fake")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testEndpointParametersWithHttpInfo(@Param("number") BigDecimal number, @Param("_double") Double _double, @Param("patternWithoutDelimiter") String patternWithoutDelimiter, @Param("_byte") byte[] _byte, @Param("integer") Integer integer, @Param("int32") Integer int32, @Param("int64") Long int64, @Param("_float") Float _float, @Param("string") String string, @Param("binary") File binary, @Param("date") LocalDate date, @Param("dateTime") OffsetDateTime dateTime, @Param("password") String password, @Param("paramCallback") String paramCallback);
+
+
+
   /**
    * To test enum parameters
    * To test enum parameters
@@ -281,6 +524,30 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testEnumParameters(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumQueryStringArray") List<String> enumQueryStringArray, @Param("enumQueryString") String enumQueryString, @Param("enumQueryInteger") Integer enumQueryInteger, @Param("enumQueryDouble") Double enumQueryDouble, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString);
 
+  /**
+   * To test enum parameters
+   * Similar to <code>testEnumParameters</code> but it also returns the http response headers .
+   * To test enum parameters
+   * @param enumHeaderStringArray Header parameter enum test (string array) (optional)
+   * @param enumHeaderString Header parameter enum test (string) (optional, default to -efg)
+   * @param enumQueryStringArray Query parameter enum test (string array) (optional)
+   * @param enumQueryString Query parameter enum test (string) (optional, default to -efg)
+   * @param enumQueryInteger Query parameter enum test (double) (optional)
+   * @param enumQueryDouble Query parameter enum test (double) (optional)
+   * @param enumFormStringArray Form parameter enum test (string array) (optional)
+   * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
+   */
+  @RequestLine("GET /fake?enum_query_string_array={enumQueryStringArray}&enum_query_string={enumQueryString}&enum_query_integer={enumQueryInteger}&enum_query_double={enumQueryDouble}")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+    "enum_header_string_array: {enumHeaderStringArray}",
+    
+    "enum_header_string: {enumHeaderString}"
+  })
+  HttpResponse<Void> testEnumParametersWithHttpInfo(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumQueryStringArray") List<String> enumQueryStringArray, @Param("enumQueryString") String enumQueryString, @Param("enumQueryInteger") Integer enumQueryInteger, @Param("enumQueryDouble") Double enumQueryDouble, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString);
+
+
   /**
    * To test enum parameters
    * To test enum parameters
@@ -313,6 +580,35 @@ public interface FakeApi extends ApiClient.Api {
   void testEnumParameters(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * To test enum parameters
+  * To test enum parameters
+  * Note, this is equivalent to the other <code>testEnumParameters</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param enumHeaderStringArray Header parameter enum test (string array) (optional)
+              * @param enumHeaderString Header parameter enum test (string) (optional, default to -efg)
+              * @param enumFormStringArray Form parameter enum test (string array) (optional)
+              * @param enumFormString Form parameter enum test (string) (optional, default to -efg)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>enumQueryStringArray - Query parameter enum test (string array) (optional)</li>
+          *   <li>enumQueryString - Query parameter enum test (string) (optional, default to -efg)</li>
+          *   <li>enumQueryInteger - Query parameter enum test (double) (optional)</li>
+          *   <li>enumQueryDouble - Query parameter enum test (double) (optional)</li>
+      *   </ul>
+      */
+      @RequestLine("GET /fake?enum_query_string_array={enumQueryStringArray}&enum_query_string={enumQueryString}&enum_query_integer={enumQueryInteger}&enum_query_double={enumQueryDouble}")
+      @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+          "enum_header_string_array: {enumHeaderStringArray}",
+      
+          "enum_header_string: {enumHeaderString}"
+      })
+   HttpResponse<Void> testEnumParametersWithHttpInfo(@Param("enumHeaderStringArray") List<String> enumHeaderStringArray, @Param("enumHeaderString") String enumHeaderString, @Param("enumFormStringArray") List<String> enumFormStringArray, @Param("enumFormString") String enumFormString, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testEnumParameters</code> method in a fluent style.
    */
@@ -354,6 +650,27 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testGroupParameters(@Param("requiredStringGroup") Integer requiredStringGroup, @Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("requiredInt64Group") Long requiredInt64Group, @Param("stringGroup") Integer stringGroup, @Param("booleanGroup") Boolean booleanGroup, @Param("int64Group") Long int64Group);
 
+  /**
+   * Fake endpoint to test group parameters (optional)
+   * Similar to <code>testGroupParameters</code> but it also returns the http response headers .
+   * Fake endpoint to test group parameters (optional)
+   * @param requiredStringGroup Required String in group parameters (required)
+   * @param requiredBooleanGroup Required Boolean in group parameters (required)
+   * @param requiredInt64Group Required Integer in group parameters (required)
+   * @param stringGroup String in group parameters (optional)
+   * @param booleanGroup Boolean in group parameters (optional)
+   * @param int64Group Integer in group parameters (optional)
+   */
+  @RequestLine("DELETE /fake?required_string_group={requiredStringGroup}&required_int64_group={requiredInt64Group}&string_group={stringGroup}&int64_group={int64Group}")
+  @Headers({
+    "Accept: application/json",
+    "required_boolean_group: {requiredBooleanGroup}",
+    
+    "boolean_group: {booleanGroup}"
+  })
+  HttpResponse<Void> testGroupParametersWithHttpInfo(@Param("requiredStringGroup") Integer requiredStringGroup, @Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("requiredInt64Group") Long requiredInt64Group, @Param("stringGroup") Integer stringGroup, @Param("booleanGroup") Boolean booleanGroup, @Param("int64Group") Long int64Group);
+
+
   /**
    * Fake endpoint to test group parameters (optional)
    * Fake endpoint to test group parameters (optional)
@@ -383,6 +700,32 @@ public interface FakeApi extends ApiClient.Api {
   void testGroupParameters(@Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("booleanGroup") Boolean booleanGroup, @QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Fake endpoint to test group parameters (optional)
+  * Fake endpoint to test group parameters (optional)
+  * Note, this is equivalent to the other <code>testGroupParameters</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+              * @param requiredBooleanGroup Required Boolean in group parameters (required)
+              * @param booleanGroup Boolean in group parameters (optional)
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>requiredStringGroup - Required String in group parameters (required)</li>
+          *   <li>requiredInt64Group - Required Integer in group parameters (required)</li>
+          *   <li>stringGroup - String in group parameters (optional)</li>
+          *   <li>int64Group - Integer in group parameters (optional)</li>
+      *   </ul>
+      */
+      @RequestLine("DELETE /fake?required_string_group={requiredStringGroup}&required_int64_group={requiredInt64Group}&string_group={stringGroup}&int64_group={int64Group}")
+      @Headers({
+    "Accept: application/json",
+          "required_boolean_group: {requiredBooleanGroup}",
+      
+          "boolean_group: {booleanGroup}"
+      })
+   HttpResponse<Void> testGroupParametersWithHttpInfo(@Param("requiredBooleanGroup") Boolean requiredBooleanGroup, @Param("booleanGroup") Boolean booleanGroup, @QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testGroupParameters</code> method in a fluent style.
    */
@@ -417,6 +760,21 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testInlineAdditionalProperties(Map<String, String> requestBody);
 
+  /**
+   * test inline additionalProperties
+   * Similar to <code>testInlineAdditionalProperties</code> but it also returns the http response headers .
+   * 
+   * @param requestBody request body (required)
+   */
+  @RequestLine("POST /fake/inline-additionalProperties")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testInlineAdditionalPropertiesWithHttpInfo(Map<String, String> requestBody);
+
+
+
   /**
    * test json serialization of form data
    * 
@@ -430,6 +788,22 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testJsonFormData(@Param("param") String param, @Param("param2") String param2);
 
+  /**
+   * test json serialization of form data
+   * Similar to <code>testJsonFormData</code> but it also returns the http response headers .
+   * 
+   * @param param field1 (required)
+   * @param param2 field2 (required)
+   */
+  @RequestLine("GET /fake/jsonFormData")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testJsonFormDataWithHttpInfo(@Param("param") String param, @Param("param2") String param2);
+
+
+
   /**
    * 
    * To test the collection format in query parameters
@@ -447,6 +821,25 @@ public interface FakeApi extends ApiClient.Api {
   })
   void testQueryParameterCollectionFormat(@Param("pipe") List<String> pipe, @Param("ioutil") List<String> ioutil, @Param("http") List<String> http, @Param("url") List<String> url, @Param("context") List<String> context, @Param("allowEmpty") String allowEmpty, @Param("language") Map<String, String> language);
 
+  /**
+   * 
+   * Similar to <code>testQueryParameterCollectionFormat</code> but it also returns the http response headers .
+   * To test the collection format in query parameters
+   * @param pipe  (required)
+   * @param ioutil  (required)
+   * @param http  (required)
+   * @param url  (required)
+   * @param context  (required)
+   * @param allowEmpty  (required)
+   * @param language  (optional)
+   */
+  @RequestLine("PUT /fake/test-query-parameters?pipe={pipe}&ioutil={ioutil}&http={http}&url={url}&context={context}&language={language}&allowEmpty={allowEmpty}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(@Param("pipe") List<String> pipe, @Param("ioutil") List<String> ioutil, @Param("http") List<String> http, @Param("url") List<String> url, @Param("context") List<String> context, @Param("allowEmpty") String allowEmpty, @Param("language") Map<String, String> language);
+
+
   /**
    * 
    * To test the collection format in query parameters
@@ -474,6 +867,30 @@ public interface FakeApi extends ApiClient.Api {
   void testQueryParameterCollectionFormat(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * 
+  * To test the collection format in query parameters
+  * Note, this is equivalent to the other <code>testQueryParameterCollectionFormat</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>pipe -  (required)</li>
+          *   <li>ioutil -  (required)</li>
+          *   <li>http -  (required)</li>
+          *   <li>url -  (required)</li>
+          *   <li>context -  (required)</li>
+          *   <li>language -  (optional)</li>
+          *   <li>allowEmpty -  (required)</li>
+      *   </ul>
+      */
+      @RequestLine("PUT /fake/test-query-parameters?pipe={pipe}&ioutil={ioutil}&http={http}&url={url}&context={context}&language={language}&allowEmpty={allowEmpty}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<Void> testQueryParameterCollectionFormatWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>testQueryParameterCollectionFormat</code> method in a fluent style.
    */

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Client;
 
@@ -27,4 +28,20 @@ public interface FakeClassnameTags123Api extends ApiClient.Api {
     "Accept: application/json",
   })
   Client testClassname(Client client);
+
+  /**
+   * To test class name in snake case
+   * Similar to <code>testClassname</code> but it also returns the http response headers .
+   * To test class name in snake case
+   * @param client client model (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("PATCH /fake_classname_test")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Client> testClassnameWithHttpInfo(Client client);
+
+
 }

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import java.io.File;
 import org.openapitools.client.model.ModelApiResponse;
@@ -30,6 +31,21 @@ public interface PetApi extends ApiClient.Api {
   })
   void addPet(Pet pet);
 
+  /**
+   * Add a new pet to the store
+   * Similar to <code>addPet</code> but it also returns the http response headers .
+   * 
+   * @param pet Pet object that needs to be added to the store (required)
+   */
+  @RequestLine("POST /pet")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> addPetWithHttpInfo(Pet pet);
+
+
+
   /**
    * Deletes a pet
    * 
@@ -43,6 +59,22 @@ public interface PetApi extends ApiClient.Api {
   })
   void deletePet(@Param("petId") Long petId, @Param("apiKey") String apiKey);
 
+  /**
+   * Deletes a pet
+   * Similar to <code>deletePet</code> but it also returns the http response headers .
+   * 
+   * @param petId Pet id to delete (required)
+   * @param apiKey  (optional)
+   */
+  @RequestLine("DELETE /pet/{petId}")
+  @Headers({
+    "Accept: application/json",
+    "api_key: {apiKey}"
+  })
+  HttpResponse<Void> deletePetWithHttpInfo(@Param("petId") Long petId, @Param("apiKey") String apiKey);
+
+
+
   /**
    * Finds Pets by status
    * Multiple status values can be provided with comma separated strings
@@ -55,6 +87,20 @@ public interface PetApi extends ApiClient.Api {
   })
   List<Pet> findPetsByStatus(@Param("status") List<String> status);
 
+  /**
+   * Finds Pets by status
+   * Similar to <code>findPetsByStatus</code> but it also returns the http response headers .
+   * Multiple status values can be provided with comma separated strings
+   * @param status Status values that need to be considered for filter (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /pet/findByStatus?status={status}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<List<Pet>> findPetsByStatusWithHttpInfo(@Param("status") List<String> status);
+
+
   /**
    * Finds Pets by status
    * Multiple status values can be provided with comma separated strings
@@ -77,6 +123,25 @@ public interface PetApi extends ApiClient.Api {
   List<Pet> findPetsByStatus(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Finds Pets by status
+  * Multiple status values can be provided with comma separated strings
+  * Note, this is equivalent to the other <code>findPetsByStatus</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>status - Status values that need to be considered for filter (required)</li>
+      *   </ul>
+          * @return List&lt;Pet&gt;
+      */
+      @RequestLine("GET /pet/findByStatus?status={status}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<List<Pet>> findPetsByStatusWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>findPetsByStatus</code> method in a fluent style.
    */
@@ -101,6 +166,22 @@ public interface PetApi extends ApiClient.Api {
   })
   Set<Pet> findPetsByTags(@Param("tags") Set<String> tags);
 
+  /**
+   * Finds Pets by tags
+   * Similar to <code>findPetsByTags</code> but it also returns the http response headers .
+   * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+   * @param tags Tags to filter by (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   * @deprecated
+   */
+  @Deprecated
+  @RequestLine("GET /pet/findByTags?tags={tags}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Set<Pet>> findPetsByTagsWithHttpInfo(@Param("tags") Set<String> tags);
+
+
   /**
    * Finds Pets by tags
    * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
@@ -125,6 +206,27 @@ public interface PetApi extends ApiClient.Api {
   Set<Pet> findPetsByTags(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Finds Pets by tags
+  * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+  * Note, this is equivalent to the other <code>findPetsByTags</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>tags - Tags to filter by (required)</li>
+      *   </ul>
+          * @return Set&lt;Pet&gt;
+          * @deprecated
+      */
+          @Deprecated
+      @RequestLine("GET /pet/findByTags?tags={tags}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<Set<Pet>> findPetsByTagsWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>findPetsByTags</code> method in a fluent style.
    */
@@ -147,6 +249,21 @@ public interface PetApi extends ApiClient.Api {
   })
   Pet getPetById(@Param("petId") Long petId);
 
+  /**
+   * Find pet by ID
+   * Similar to <code>getPetById</code> but it also returns the http response headers .
+   * Returns a single pet
+   * @param petId ID of pet to return (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /pet/{petId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Pet> getPetByIdWithHttpInfo(@Param("petId") Long petId);
+
+
+
   /**
    * Update an existing pet
    * 
@@ -159,6 +276,21 @@ public interface PetApi extends ApiClient.Api {
   })
   void updatePet(Pet pet);
 
+  /**
+   * Update an existing pet
+   * Similar to <code>updatePet</code> but it also returns the http response headers .
+   * 
+   * @param pet Pet object that needs to be added to the store (required)
+   */
+  @RequestLine("PUT /pet")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updatePetWithHttpInfo(Pet pet);
+
+
+
   /**
    * Updates a pet in the store with form data
    * 
@@ -173,6 +305,23 @@ public interface PetApi extends ApiClient.Api {
   })
   void updatePetWithForm(@Param("petId") Long petId, @Param("name") String name, @Param("status") String status);
 
+  /**
+   * Updates a pet in the store with form data
+   * Similar to <code>updatePetWithForm</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet that needs to be updated (required)
+   * @param name Updated name of the pet (optional)
+   * @param status Updated status of the pet (optional)
+   */
+  @RequestLine("POST /pet/{petId}")
+  @Headers({
+    "Content-Type: application/x-www-form-urlencoded",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updatePetWithFormWithHttpInfo(@Param("petId") Long petId, @Param("name") String name, @Param("status") String status);
+
+
+
   /**
    * uploads an image
    * 
@@ -188,6 +337,24 @@ public interface PetApi extends ApiClient.Api {
   })
   ModelApiResponse uploadFile(@Param("petId") Long petId, @Param("additionalMetadata") String additionalMetadata, @Param("file") File file);
 
+  /**
+   * uploads an image
+   * Similar to <code>uploadFile</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet to update (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @param file file to upload (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /pet/{petId}/uploadImage")
+  @Headers({
+    "Content-Type: multipart/form-data",
+    "Accept: application/json",
+  })
+  HttpResponse<ModelApiResponse> uploadFileWithHttpInfo(@Param("petId") Long petId, @Param("additionalMetadata") String additionalMetadata, @Param("file") File file);
+
+
+
   /**
    * uploads an image (required)
    * 
@@ -202,4 +369,22 @@ public interface PetApi extends ApiClient.Api {
     "Accept: application/json",
   })
   ModelApiResponse uploadFileWithRequiredFile(@Param("petId") Long petId, @Param("requiredFile") File requiredFile, @Param("additionalMetadata") String additionalMetadata);
+
+  /**
+   * uploads an image (required)
+   * Similar to <code>uploadFileWithRequiredFile</code> but it also returns the http response headers .
+   * 
+   * @param petId ID of pet to update (required)
+   * @param requiredFile file to upload (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /fake/{petId}/uploadImageWithRequiredFile")
+  @Headers({
+    "Content-Type: multipart/form-data",
+    "Accept: application/json",
+  })
+  HttpResponse<ModelApiResponse> uploadFileWithRequiredFileWithHttpInfo(@Param("petId") Long petId, @Param("requiredFile") File requiredFile, @Param("additionalMetadata") String additionalMetadata);
+
+
 }

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.Order;
 
@@ -26,6 +27,20 @@ public interface StoreApi extends ApiClient.Api {
   })
   void deleteOrder(@Param("orderId") String orderId);
 
+  /**
+   * Delete purchase order by ID
+   * Similar to <code>deleteOrder</code> but it also returns the http response headers .
+   * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+   * @param orderId ID of the order that needs to be deleted (required)
+   */
+  @RequestLine("DELETE /store/order/{orderId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> deleteOrderWithHttpInfo(@Param("orderId") String orderId);
+
+
+
   /**
    * Returns pet inventories by status
    * Returns a map of status codes to quantities
@@ -37,6 +52,20 @@ public interface StoreApi extends ApiClient.Api {
   })
   Map<String, Integer> getInventory();
 
+  /**
+   * Returns pet inventories by status
+   * Similar to <code>getInventory</code> but it also returns the http response headers .
+   * Returns a map of status codes to quantities
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /store/inventory")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Map<String, Integer>> getInventoryWithHttpInfo();
+
+
+
   /**
    * Find purchase order by ID
    * For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
@@ -49,6 +78,21 @@ public interface StoreApi extends ApiClient.Api {
   })
   Order getOrderById(@Param("orderId") Long orderId);
 
+  /**
+   * Find purchase order by ID
+   * Similar to <code>getOrderById</code> but it also returns the http response headers .
+   * For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+   * @param orderId ID of pet that needs to be fetched (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /store/order/{orderId}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Order> getOrderByIdWithHttpInfo(@Param("orderId") Long orderId);
+
+
+
   /**
    * Place an order for a pet
    * 
@@ -61,4 +105,20 @@ public interface StoreApi extends ApiClient.Api {
     "Accept: application/json",
   })
   Order placeOrder(Order order);
+
+  /**
+   * Place an order for a pet
+   * Similar to <code>placeOrder</code> but it also returns the http response headers .
+   * 
+   * @param order order placed for purchasing the pet (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("POST /store/order")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Order> placeOrderWithHttpInfo(Order order);
+
+
 }

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

@@ -2,6 +2,7 @@ package org.openapitools.client.api;
 
 import org.openapitools.client.ApiClient;
 import org.openapitools.client.EncodingUtils;
+import org.openapitools.client.model.HttpResponse;
 
 import org.openapitools.client.model.User;
 
@@ -27,6 +28,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUser(User user);
 
+  /**
+   * Create user
+   * Similar to <code>createUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param user Created user object (required)
+   */
+  @RequestLine("POST /user")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUserWithHttpInfo(User user);
+
+
+
   /**
    * Creates list of users with given input array
    * 
@@ -39,6 +55,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUsersWithArrayInput(List<User> user);
 
+  /**
+   * Creates list of users with given input array
+   * Similar to <code>createUsersWithArrayInput</code> but it also returns the http response headers .
+   * 
+   * @param user List of user object (required)
+   */
+  @RequestLine("POST /user/createWithArray")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUsersWithArrayInputWithHttpInfo(List<User> user);
+
+
+
   /**
    * Creates list of users with given input array
    * 
@@ -51,6 +82,21 @@ public interface UserApi extends ApiClient.Api {
   })
   void createUsersWithListInput(List<User> user);
 
+  /**
+   * Creates list of users with given input array
+   * Similar to <code>createUsersWithListInput</code> but it also returns the http response headers .
+   * 
+   * @param user List of user object (required)
+   */
+  @RequestLine("POST /user/createWithList")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> createUsersWithListInputWithHttpInfo(List<User> user);
+
+
+
   /**
    * Delete user
    * This can only be done by the logged in user.
@@ -62,6 +108,20 @@ public interface UserApi extends ApiClient.Api {
   })
   void deleteUser(@Param("username") String username);
 
+  /**
+   * Delete user
+   * Similar to <code>deleteUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param username The name that needs to be deleted (required)
+   */
+  @RequestLine("DELETE /user/{username}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> deleteUserWithHttpInfo(@Param("username") String username);
+
+
+
   /**
    * Get user by user name
    * 
@@ -74,6 +134,21 @@ public interface UserApi extends ApiClient.Api {
   })
   User getUserByName(@Param("username") String username);
 
+  /**
+   * Get user by user name
+   * Similar to <code>getUserByName</code> but it also returns the http response headers .
+   * 
+   * @param username The name that needs to be fetched. Use user1 for testing. (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /user/{username}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<User> getUserByNameWithHttpInfo(@Param("username") String username);
+
+
+
   /**
    * Logs user into the system
    * 
@@ -87,6 +162,21 @@ public interface UserApi extends ApiClient.Api {
   })
   String loginUser(@Param("username") String username, @Param("password") String password);
 
+  /**
+   * Logs user into the system
+   * Similar to <code>loginUser</code> but it also returns the http response headers .
+   * 
+   * @param username The user name for login (required)
+   * @param password The password for login in clear text (required)
+   * @return A HttpResponse that wraps the response boyd and the http headers.
+   */
+  @RequestLine("GET /user/login?username={username}&password={password}")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<String> loginUserWithHttpInfo(@Param("username") String username, @Param("password") String password);
+
+
   /**
    * Logs user into the system
    * 
@@ -110,6 +200,26 @@ public interface UserApi extends ApiClient.Api {
   String loginUser(@QueryMap(encoded=true) Map<String, Object> queryParams);
 
   /**
+  * Logs user into the system
+  * 
+  * Note, this is equivalent to the other <code>loginUser</code> that receives the query parameters as a map,
+  * but this one also exposes the Http response headers
+      * @param queryParams Map of query parameters as name-value pairs
+      *   <p>The following elements may be specified in the query map:</p>
+      *   <ul>
+          *   <li>username - The user name for login (required)</li>
+          *   <li>password - The password for login in clear text (required)</li>
+      *   </ul>
+          * @return String
+      */
+      @RequestLine("GET /user/login?username={username}&password={password}")
+      @Headers({
+    "Accept: application/json",
+      })
+   HttpResponse<String> loginUserWithHttpInfo(@QueryMap(encoded=true) Map<String, Object> queryParams);
+
+
+   /**
    * A convenience class for generating query parameters for the
    * <code>loginUser</code> method in a fluent style.
    */
@@ -134,6 +244,19 @@ public interface UserApi extends ApiClient.Api {
   })
   void logoutUser();
 
+  /**
+   * Logs out current logged in user session
+   * Similar to <code>logoutUser</code> but it also returns the http response headers .
+   * 
+   */
+  @RequestLine("GET /user/logout")
+  @Headers({
+    "Accept: application/json",
+  })
+  HttpResponse<Void> logoutUserWithHttpInfo();
+
+
+
   /**
    * Updated user
    * This can only be done by the logged in user.
@@ -146,4 +269,20 @@ public interface UserApi extends ApiClient.Api {
     "Accept: application/json",
   })
   void updateUser(@Param("username") String username, User user);
+
+  /**
+   * Updated user
+   * Similar to <code>updateUser</code> but it also returns the http response headers .
+   * This can only be done by the logged in user.
+   * @param username name that need to be deleted (required)
+   * @param user Updated user object (required)
+   */
+  @RequestLine("PUT /user/{username}")
+  @Headers({
+    "Content-Type: application/json",
+    "Accept: application/json",
+  })
+  HttpResponse<Void> updateUserWithHttpInfo(@Param("username") String username, User user);
+
+
 }

samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/HttpResponse.java

@@ -0,0 +1,24 @@
+package org.openapitools.client.model;
+
+import java.util.Map;
+import java.util.Collection;
+
+public class HttpResponse<T>{
+
+  private Map<String, Collection<String>> headers;
+
+  private T body;
+
+  public HttpResponse(Map<String, Collection<String>> headers, T body) {
+    this.headers = headers;
+    this.body = body;
+  }
+
+  public T getBody(){
+    return body;
+  }
+
+  public Map<String, Collection<String>> getHeaders(){
+    return headers;
+  }
+}