[JAVA] Add apache httpclient library to java clients (#10218)

* Add apache java client option

* Add sample apache client config

* Switch serialization library, use time formatter

* Add pom template for apache dependencies

* Add initial implementation of ApiClient using apache

* Add apache api template

Plus switch to TypeReference to handle generic types

* Add support for sending json data

* Generate test stubs with @Ignore

* Add accept header

* Remove unnecessary builder assignments

* Set responseHeaders instance variable

* Switch to general serialize / deserialize functions

* Handle sending url encoded form data

* Split response processing into new method

* Allow requests without body

* Use general HttpResponse interface

If the method doesn't need to close it

* Use clients connection timeout

* Add constructor accepting custom client

* Handle multipart and direct file uploads

* Support file downloading

Based on the implementation in the jersey client

* Handle missing content disposition

* Raise error if body given for an unexpected method

* Use try with resources for response handling

* Remove unused url parameter encode method

* Handle content type parse exception

* Improve response content type handling

Would have had issues with content type headers containing a charset

* Make all set methods return client

* Add basic readme

* Send content type with files

* Set domain and path on cookies

Otherwise they will be excluded from the request

* Use consistent quoting in error messages

* Add generated apache sample

* Add generated docs changes

* update samples

* rename library, update samples, docs

* update readme

Co-authored-by: Harry White <hwhite@atlassian.com>

README.md

@@ -67,7 +67,7 @@ OpenAPI Generator allows generation of API client libraries (SDK generation), se
 
 |                                  | Languages/Frameworks                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
 | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| **API clients**                  | **ActionScript**, **Ada**, **Apex**, **Bash**, **C**, **C#** (.net 2.0, 3.5 or later, .NET Standard 1.3 - 2.0, .NET Core 2.0, .NET 5.0. Libraries: RestSharp, HttpClient), **C++** (Arduino, cpp-restsdk, Qt5, Tizen, Unreal Engine 4), **Clojure**, **Crystal**, **Dart**, **Elixir**, **Elm**, **Eiffel**, **Erlang**, **Go**, **Groovy**, **Haskell** (http-client, Servant), **Java** (Jersey1.x, Jersey2.x, OkHttp, Retrofit1.x, Retrofit2.x, Feign, RestTemplate, RESTEasy, Vertx, Google API Client Library for Java, Rest-assured, Spring 5 Web Client, MicroProfile Rest Client), **k6**, **Kotlin**, **Lua**, **Nim**, **Node.js/JavaScript** (ES5, ES6, AngularJS with Google Closure Compiler annotations, Flow types, Apollo GraphQL DataStore), **Objective-C**, **OCaml**, **Perl**, **PHP**, **PowerShell**, **Python**, **R**, **Ruby**, **Rust** (hyper, reqwest, rust-server), **Scala** (akka, http4s, scalaz, sttp, swagger-async-httpclient), **Swift** (2.x, 3.x, 4.x, 5.x), **Typescript** (AngularJS, Angular (2.x - 11.x), Aurelia, Axios, Fetch, Inversify, jQuery, Nestjs, Node, redux-query, Rxjs) |
+| **API clients**                  | **ActionScript**, **Ada**, **Apex**, **Bash**, **C**, **C#** (.net 2.0, 3.5 or later, .NET Standard 1.3 - 2.0, .NET Core 2.0, .NET 5.0. Libraries: RestSharp, HttpClient), **C++** (Arduino, cpp-restsdk, Qt5, Tizen, Unreal Engine 4), **Clojure**, **Crystal**, **Dart**, **Elixir**, **Elm**, **Eiffel**, **Erlang**, **Go**, **Groovy**, **Haskell** (http-client, Servant), **Java** (Apache HttpClient, Jersey1.x, Jersey2.x, OkHttp, Retrofit1.x, Retrofit2.x, Feign, RestTemplate, RESTEasy, Vertx, Google API Client Library for Java, Rest-assured, Spring 5 Web Client, MicroProfile Rest Client), **k6**, **Kotlin**, **Lua**, **Nim**, **Node.js/JavaScript** (ES5, ES6, AngularJS with Google Closure Compiler annotations, Flow types, Apollo GraphQL DataStore), **Objective-C**, **OCaml**, **Perl**, **PHP**, **PowerShell**, **Python**, **R**, **Ruby**, **Rust** (hyper, reqwest, rust-server), **Scala** (akka, http4s, scalaz, sttp, swagger-async-httpclient), **Swift** (2.x, 3.x, 4.x, 5.x), **Typescript** (AngularJS, Angular (2.x - 11.x), Aurelia, Axios, Fetch, Inversify, jQuery, Nestjs, Node, redux-query, Rxjs) |
 | **Server stubs**                 | **Ada**, **C#** (ASP.NET Core, NancyFx), **C++** (Pistache, Restbed, Qt5 QHTTPEngine), **Erlang**, **F#** (Giraffe), **Go** (net/http, Gin, Echo), **Haskell** (Servant), **Java** (MSF4J, Spring, Undertow, JAX-RS: CDI, CXF, Inflector, Jersey, RestEasy, Play Framework, [PKMST](https://github.com/ProKarma-Inc/pkmst-getting-started-examples), [Vert.x](https://vertx.io/)), **Kotlin** (Spring Boot, Ktor, Vertx), **PHP** (Laravel, Lumen, [Mezzio (fka Zend Expressive)](https://github.com/mezzio/mezzio), Slim, Silex, [Symfony](https://symfony.com/)), **Python** (FastAPI, Flask), **NodeJS**, **Ruby** (Sinatra, Rails5), **Rust** (rust-server), **Scala** (Akka, [Finch](https://github.com/finagle/finch), [Lagom](https://github.com/lagom/lagom), [Play](https://www.playframework.com/), Scalatra)                                                                                                                                                                                         |
 | **API documentation generators** | **HTML**, **Confluence Wiki**, **Asciidoc**, **Markdown**, **PlantUML**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
 | **Configuration files**          | [**Apache2**](https://httpd.apache.org/)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
@@ -884,6 +884,7 @@ Here is a list of template creators:
    * Java (Google APIs Client Library): @charlescapps
    * Java (Rest-assured): @viclovsky
    * Java (Java 11 Native HTTP client): @bbdouglas
+   * Java (Apache HttpClient): @harrywhite4
    * Javascript/NodeJS: @jfiala
    * Javascript (Apollo DataSource): @erithmetic
    * Javascript (Closure-annotated Angular) @achew22

bin/configs/java-apache-httpclient.yaml

@@ -0,0 +1,8 @@
+generatorName: java
+outputDir: samples/client/petstore/java/apache-httpclient
+library: apache-httpclient
+inputSpec: modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/Java
+additionalProperties:
+  artifactId: petstore-apache-httpclient
+  hideGenerationTimestamp: true

docs/generators/java.md

@@ -36,7 +36,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |invokerPackage|root package for generated code| |org.openapitools.client|
 |java8|Use Java8 classes instead of third party equivalents. Starting in 5.x, JDK8 is the default and the support for JDK7, JDK6 has been dropped|<dl><dt>**true**</dt><dd>Use Java 8 classes such as Base64</dd><dt>**false**</dt><dd>Various third party libraries as needed</dd></dl>|true|
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C#have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
-|library|library template (sub-template) to use|<dl><dt>**jersey1**</dt><dd>HTTP client: Jersey client 1.19.x. JSON processing: Jackson 2.9.x. Enable gzip request encoding using '-DuseGzipFeature=true'. IMPORTANT NOTE: jersey 1.x is no longer actively maintained so please upgrade to 'jersey2' or other HTTP libaries instead.</dd><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.9.x</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 10.x. JSON processing: Jackson 2.9.x.</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 3.x. JSON processing: Gson 2.8.x. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 3.x. JSON processing: Gson 2.x (Retrofit 2.3.0). Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 4.x. JSON processing: Jackson 2.9.x</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.x. JSON processing: Jackson 2.9.x</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 1.x. JSON processing: JSON-B</dd></dl>|okhttp-gson|
+|library|library template (sub-template) to use|<dl><dt>**jersey1**</dt><dd>HTTP client: Jersey client 1.19.x. JSON processing: Jackson 2.9.x. Enable gzip request encoding using '-DuseGzipFeature=true'. IMPORTANT NOTE: jersey 1.x is no longer actively maintained so please upgrade to 'jersey2' or other HTTP libaries instead.</dd><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.9.x</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 10.x. JSON processing: Jackson 2.9.x.</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 3.x. JSON processing: Gson 2.8.x. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 3.x. JSON processing: Gson 2.x (Retrofit 2.3.0). Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 4.x. JSON processing: Jackson 2.9.x</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.x. JSON processing: Jackson 2.9.x</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 1.x. JSON processing: JSON-B</dd><dt>**apache-httpclient**</dt><dd>HTTP client: Apache httpclient 4.x</dd></dl>|okhttp-gson|
 |licenseName|The name of the license| |Unlicense|
 |licenseUrl|The URL of the license| |http://unlicense.org|
 |microprofileFramework|Framework for microprofile. Possible values &quot;kumuluzee&quot;| |null|

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

@@ -84,6 +84,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
     public static final String RETROFIT_2 = "retrofit2";
     public static final String VERTX = "vertx";
     public static final String MICROPROFILE = "microprofile";
+    public static final String APACHE = "apache-httpclient";
 
     public static final String SERIALIZATION_LIBRARY_GSON = "gson";
     public static final String SERIALIZATION_LIBRARY_JACKSON = "jackson";
@@ -167,7 +168,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         supportedLibraries.put(REST_ASSURED, "HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8");
         supportedLibraries.put(NATIVE, "HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+");
         supportedLibraries.put(MICROPROFILE, "HTTP client: Microprofile client 1.x. JSON processing: JSON-B");
-
+        supportedLibraries.put(APACHE, "HTTP client: Apache httpclient 4.x");
 
         CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use");
         libraryOption.setEnum(supportedLibraries);
@@ -341,7 +342,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         }
 
         // helper for client library that allow to parse/format java.time.OffsetDateTime or org.threeten.bp.OffsetDateTime
-        if (additionalProperties.containsKey("jsr310") && (isLibrary(WEBCLIENT) || isLibrary(VERTX) || isLibrary(RESTTEMPLATE) || isLibrary(RESTEASY) || isLibrary(MICROPROFILE) || isLibrary(JERSEY1) || isLibrary(JERSEY2))) {
+        if (additionalProperties.containsKey("jsr310") && (isLibrary(WEBCLIENT) || isLibrary(VERTX) || isLibrary(RESTTEMPLATE) || isLibrary(RESTEASY) || isLibrary(MICROPROFILE) || isLibrary(JERSEY1) || isLibrary(JERSEY2) || isLibrary(APACHE))) {
             supportingFiles.add(new SupportingFile("JavaTimeFormatter.mustache", invokerFolder, "JavaTimeFormatter.java"));
         }
 
@@ -490,6 +491,9 @@ public class JavaClientCodegen extends AbstractJavaCodegen
                 supportingFiles.add(new SupportingFile("kumuluzee.config.yaml.mustache", "src/main/resources", "config.yaml"));
                 supportingFiles.add(new SupportingFile("kumuluzee.beans.xml.mustache", "src/main/resources/META-INF", "beans.xml"));
             }
+        } else if (APACHE.equals(getLibrary())) {
+            setJava8ModeAndAdditionalProperties(true);
+            forceSerializationLibrary(SERIALIZATION_LIBRARY_JACKSON);
         } else {
             LOGGER.error("Unknown library option (-l/--library): {}", getLibrary());
         }

modules/openapi-generator/src/main/resources/Java/libraries/apache/README.mustache

@@ -0,0 +1,196 @@
+# {{artifactId}}
+
+{{appName}}
+
+- API version: {{appVersion}}
+{{^hideGenerationTimestamp}}
+
+- Build date: {{generatedDate}}
+{{/hideGenerationTimestamp}}
+
+{{#appDescriptionWithNewLines}}{{{appDescriptionWithNewLines}}}{{/appDescriptionWithNewLines}}
+
+{{#infoUrl}}
+  For more information, please visit [{{{infoUrl}}}]({{{infoUrl}}})
+{{/infoUrl}}
+
+*Automatically generated by the [OpenAPI Generator](https://openapi-generator.tech)*
+
+## Requirements
+
+Building the API client library requires:
+
+1. Java {{#java8}}1.8{{/java8}}{{^java8}}1.7{{/java8}}+
+2. Maven/Gradle
+
+## Installation
+
+To install the API client library to your local Maven repository, simply execute:
+
+```shell
+mvn clean install
+```
+
+To deploy it to a remote Maven repository instead, configure the settings of the repository and execute:
+
+```shell
+mvn clean deploy
+```
+
+Refer to the [OSSRH Guide](http://central.sonatype.org/pages/ossrh-guide.html) for more information.
+
+### Maven users
+
+Add this dependency to your project's POM:
+
+```xml
+<dependency>
+  <groupId>{{{groupId}}}</groupId>
+  <artifactId>{{{artifactId}}}</artifactId>
+  <version>{{{artifactVersion}}}</version>
+  <scope>compile</scope>
+</dependency>
+```
+
+### Gradle users
+
+Add this dependency to your project's build file:
+
+```groovy
+compile "{{{groupId}}}:{{{artifactId}}}:{{{artifactVersion}}}"
+```
+
+### Others
+
+At first generate the JAR by executing:
+
+```shell
+mvn clean package
+```
+
+Then manually install the following JARs:
+
+- `target/{{{artifactId}}}-{{{artifactVersion}}}.jar`
+- `target/lib/*.jar`
+
+## Getting Started
+
+Please follow the [installation](#installation) instruction and execute the following Java code:
+
+```java
+{{#apiInfo}}{{#apis}}{{#-first}}{{#operations}}{{#operation}}{{#-first}}
+import {{{invokerPackage}}}.*;
+import {{{invokerPackage}}}.auth.*;
+import {{{modelPackage}}}.*;
+import {{{package}}}.{{{classname}}};
+
+public class {{{classname}}}Example {
+
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("{{{basePath}}}");
+        {{#hasAuthMethods}}{{#authMethods}}{{#isBasic}}{{#isBasicBasic}}
+        // Configure HTTP basic authorization: {{{name}}}
+        HttpBasicAuth {{{name}}} = (HttpBasicAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setUsername("YOUR USERNAME");
+        {{{name}}}.setPassword("YOUR PASSWORD");{{/isBasicBasic}}{{#isBasicBearer}}
+        // Configure HTTP bearer authorization: {{{name}}}
+        HttpBearerAuth {{{name}}} = (HttpBearerAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setBearerToken("BEARER TOKEN");{{/isBasicBearer}}{{/isBasic}}{{#isApiKey}}
+        // Configure API key authorization: {{{name}}}
+        ApiKeyAuth {{{name}}} = (ApiKeyAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setApiKey("YOUR API KEY");
+        // Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+        //{{{name}}}.setApiKeyPrefix("Token");{{/isApiKey}}{{#isOAuth}}
+        // Configure OAuth2 access token for authorization: {{{name}}}
+        OAuth {{{name}}} = (OAuth) defaultClient.getAuthentication("{{{name}}}");
+        {{{name}}}.setAccessToken("YOUR ACCESS TOKEN");{{/isOAuth}}{{#isHttpSignature}}
+        // Configure HTTP signature authorization: {{{name}}}
+        HttpSignatureAuth {{{name}}} = (HttpSignatureAuth) defaultClient.getAuthentication("{{{name}}}");
+        // All the HTTP signature parameters below should be customized to your environment.
+        // Configure the keyId
+        {{{name}}}.setKeyId("YOUR KEY ID");
+        // Configure the signature algorithm
+        {{{name}}}.setSigningAlgorithm(SigningAlgorithm.HS2019);
+        // Configure the specific cryptographic algorithm
+        {{{name}}}.setAlgorithm(Algorithm.ECDSA_SHA256);
+        // Configure the cryptographic algorithm parameters, if applicable
+        {{{name}}}.setAlgorithmParameterSpec(null);
+        // Set the cryptographic digest algorithm.
+        {{{name}}}.setDigestAlgorithm("SHA-256");
+        // Set the HTTP headers that should be included in the HTTP signature.
+        {{{name}}}.setHeaders(Arrays.asList("date", "host"));
+        // Set the private key used to sign the HTTP messages
+        {{{name}}}.setPrivateKey();{{/isHttpSignature}}
+        {{/authMethods}}
+        {{/hasAuthMethods}}
+
+        {{{classname}}} apiInstance = new {{{classname}}}(defaultClient);
+        {{#allParams}}
+        {{{dataType}}} {{{paramName}}} = {{{example}}}; // {{{dataType}}} | {{{description}}}
+        {{/allParams}}
+        try {
+            {{#returnType}}{{{returnType}}} result = {{/returnType}}apiInstance.{{{operationId}}}({{#allParams}}{{{paramName}}}{{^-last}}, {{/-last}}{{/allParams}});{{#returnType}}
+            System.out.println(result);{{/returnType}}
+        } catch (ApiException e) {
+            System.err.println("Exception when calling {{{classname}}}#{{{operationId}}}");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+{{/-first}}{{/operation}}{{/operations}}{{/-first}}{{/apis}}{{/apiInfo}}
+```
+
+## Documentation for API Endpoints
+
+All URIs are relative to *{{basePath}}*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}*{{classname}}* | [**{{operationId}}**]({{apiDocPath}}{{classname}}.md#{{operationId}}) | **{{httpMethod}}** {{commonPath}}{{path}} | {{#summary}}{{summary}}{{/summary}}
+{{/operation}}{{/operations}}{{/apis}}{{/apiInfo}}
+
+## Documentation for Models
+
+{{#models}}{{#model}} - [{{classname}}]({{modelDocPath}}{{classname}}.md)
+{{/model}}{{/models}}
+
+## Documentation for Authorization
+
+{{^authMethods}}All endpoints do not require authorization.
+{{/authMethods}}Authentication schemes defined for the API:
+{{#authMethods}}### {{name}}
+
+{{#isApiKey}}
+
+- **Type**: API key
+- **API key parameter name**: {{keyParamName}}
+- **Location**: {{#isKeyInQuery}}URL query string{{/isKeyInQuery}}{{#isKeyInHeader}}HTTP header{{/isKeyInHeader}}
+{{/isApiKey}}
+{{#isBasic}}
+
+- **Type**: HTTP basic authentication
+{{/isBasic}}
+{{#isOAuth}}
+
+- **Type**: OAuth
+- **Flow**: {{flow}}
+- **Authorization URL**: {{authorizationUrl}}
+- **Scopes**: {{^scopes}}N/A{{/scopes}}
+{{#scopes}}  - {{scope}}: {{description}}
+{{/scopes}}
+{{/isOAuth}}
+
+{{/authMethods}}
+
+## Recommendation
+
+It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issues.
+
+## Author
+
+{{#apiInfo}}{{#apis}}{{#-last}}{{infoEmail}}
+{{/-last}}{{/apis}}{{/apiInfo}}

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

@@ -0,0 +1,136 @@
+{{>licenseInfo}}
+package {{package}};
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import {{invokerPackage}}.ApiException;
+import {{invokerPackage}}.ApiClient;
+import {{invokerPackage}}.Configuration;
+import {{modelPackage}}.*;
+import {{invokerPackage}}.Pair;
+
+{{#imports}}import {{import}};
+{{/imports}}
+
+
+{{^fullJavaUtil}}
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+{{/fullJavaUtil}}
+
+{{>generatedAnnotation}}
+{{#operations}}
+public class {{classname}} {
+  private ApiClient apiClient;
+
+  public {{classname}}() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public {{classname}}(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  {{#operation}}
+  /**
+   * {{summary}}
+   * {{notes}}
+   {{#allParams}}
+   * @param {{paramName}} {{description}}{{#required}} (required){{/required}}{{^required}} (optional{{^isContainer}}{{#defaultValue}}, default to {{.}}{{/defaultValue}}){{/isContainer}}{{/required}}
+   {{/allParams}}
+   {{#returnType}}
+   * @return {{returnType}}
+   {{/returnType}}
+   * @throws ApiException if fails to make API call
+   {{#isDeprecated}}
+   * @deprecated
+   {{/isDeprecated}}
+   {{#externalDocs}}
+   * {{description}}
+   * @see <a href="{{url}}">{{summary}} Documentation</a>
+   {{/externalDocs}}
+   */
+  {{#isDeprecated}}
+  @Deprecated
+  {{/isDeprecated}}
+  public {{#returnType}}{{{returnType}}} {{/returnType}}{{^returnType}}void {{/returnType}}{{operationId}}({{#allParams}}{{{dataType}}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws ApiException {
+    Object localVarPostBody = {{#bodyParam}}{{paramName}}{{/bodyParam}}{{^bodyParam}}null{{/bodyParam}};
+    {{#allParams}}{{#required}}
+    // verify the required parameter '{{paramName}}' is set
+    if ({{paramName}} == null) {
+      throw new ApiException(400, "Missing the required parameter '{{paramName}}' when calling {{operationId}}");
+    }
+    {{/required}}{{/allParams}}
+    // create path and map variables
+    String localVarPath = "{{{path}}}"{{#pathParams}}
+      .replaceAll("\\{" + "{{baseName}}" + "\\}", apiClient.escapeString({{{paramName}}}.toString())){{/pathParams}};
+
+    // query params
+    {{javaUtilPrefix}}List<Pair> localVarQueryParams = new {{javaUtilPrefix}}ArrayList<Pair>();
+    {{javaUtilPrefix}}List<Pair> localVarCollectionQueryParams = new {{javaUtilPrefix}}ArrayList<Pair>();
+    {{javaUtilPrefix}}Map<String, String> localVarHeaderParams = new {{javaUtilPrefix}}HashMap<String, String>();
+    {{javaUtilPrefix}}Map<String, String> localVarCookieParams = new {{javaUtilPrefix}}HashMap<String, String>();
+    {{javaUtilPrefix}}Map<String, Object> localVarFormParams = new {{javaUtilPrefix}}HashMap<String, Object>();
+
+    {{#queryParams}}
+    {{#collectionFormat}}localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("{{{collectionFormat}}}", {{/collectionFormat}}{{^collectionFormat}}localVarQueryParams.addAll(apiClient.parameterToPair({{/collectionFormat}}"{{baseName}}", {{paramName}}));
+    {{/queryParams}}
+
+    {{#headerParams}}if ({{paramName}} != null)
+      localVarHeaderParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
+    {{/headerParams}}
+
+    {{#cookieParams}}if ({{paramName}} != null)
+      localVarCookieParams.put("{{baseName}}", apiClient.parameterToString({{paramName}}));
+    {{/cookieParams}}
+
+    {{#formParams}}if ({{paramName}} != null)
+      localVarFormParams.put("{{baseName}}", {{paramName}});
+    {{/formParams}}
+
+    final String[] localVarAccepts = {
+      {{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}}
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}}
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { {{#authMethods}}"{{name}}"{{^-last}}, {{/-last}}{{/authMethods}} };
+
+    {{#returnType}}
+    TypeReference<{{{returnType}}}> localVarReturnType = new TypeReference<{{{returnType}}}>() {};
+    return apiClient.invokeAPI(
+    {{/returnType}}
+    {{^returnType}}
+    apiClient.invokeAPI(
+    {{/returnType}}
+        localVarPath,
+        "{{httpMethod}}",
+        localVarQueryParams,
+        localVarCollectionQueryParams,
+        localVarPostBody,
+        localVarHeaderParams,
+        localVarCookieParams,
+        localVarFormParams,
+        localVarAccept,
+        localVarContentType,
+        localVarAuthNames,
+        {{#returnType}}localVarReturnType{{/returnType}}{{^returnType}}null{{/returnType}}
+    );
+  }
+  {{/operation}}
+}
+{{/operations}}

modules/openapi-generator/src/main/resources/Java/libraries/apache/api_test.mustache

@@ -0,0 +1,52 @@
+{{>licenseInfo}}
+
+package {{package}};
+
+import {{invokerPackage}}.ApiException;
+{{#imports}}import {{import}};
+{{/imports}}
+import org.junit.Test;
+import org.junit.Ignore;
+import org.junit.Assert;
+
+{{^fullJavaUtil}}
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+{{/fullJavaUtil}}
+/**
+ * API tests for {{classname}}
+ */
+@Ignore
+public class {{classname}}Test {
+
+    private final {{classname}} api = new {{classname}}();
+
+    {{#operations}}
+    {{#operation}}
+    /**
+    {{#summary}}
+     * {{summary}}
+     *
+    {{/summary}}
+    {{#notes}}
+     * {{notes}}
+     *
+    {{/notes}}
+     * @throws ApiException
+     *          if the Api call fails
+     */
+    @Test
+    public void {{operationId}}Test() throws ApiException {
+        {{#allParams}}
+        {{{dataType}}} {{paramName}} = null;
+        {{/allParams}}
+        {{#returnType}}{{{returnType}}} response = {{/returnType}}api.{{operationId}}({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}});
+
+        // TODO: test validations
+    }
+    {{/operation}}
+    {{/operations}}
+}

modules/openapi-generator/src/main/resources/Java/libraries/apache/pom.mustache

@@ -0,0 +1,373 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>{{groupId}}</groupId>
+    <artifactId>{{artifactId}}</artifactId>
+    <packaging>jar</packaging>
+    <name>{{artifactId}}</name>
+    <version>{{artifactVersion}}</version>
+    <url>{{artifactUrl}}</url>
+    <description>{{artifactDescription}}</description>
+    <scm>
+        <connection>{{scmConnection}}</connection>
+        <developerConnection>{{scmDeveloperConnection}}</developerConnection>
+        <url>{{scmUrl}}</url>
+    </scm>
+{{#parentOverridden}}
+    <parent>
+        <groupId>{{{parentGroupId}}}</groupId>
+        <artifactId>{{{parentArtifactId}}}</artifactId>
+        <version>{{{parentVersion}}}</version>
+    </parent>
+{{/parentOverridden}}
+
+    <licenses>
+        <license>
+            <name>{{licenseName}}</name>
+            <url>{{licenseUrl}}</url>
+            <distribution>repo</distribution>
+        </license>
+    </licenses>
+
+    <developers>
+        <developer>
+            <name>{{developerName}}</name>
+            <email>{{developerEmail}}</email>
+            <organization>{{developerOrganization}}</organization>
+            <organizationUrl>{{developerOrganizationUrl}}</organizationUrl>
+        </developer>
+    </developers>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <fork>true</fork>
+                    <meminitial>128m</meminitial>
+                    <maxmem>512m</maxmem>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-J-Xss4m</arg><!-- Compiling the generated JSON.java file may require larger stack size. -->
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+                <version>3.0.0-M1</version>
+                <executions>
+                    <execution>
+                        <id>enforce-maven</id>
+                        <goals>
+                            <goal>enforce</goal>
+                        </goals>
+                        <configuration>
+                            <rules>
+                                <requireMavenVersion>
+                                    <version>2.2.0</version>
+                                </requireMavenVersion>
+                            </rules>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.12</version>
+                <configuration>
+                    <systemProperties>
+                        <property>
+                            <name>loggerPath</name>
+                            <value>conf/log4j.properties</value>
+                        </property>
+                    </systemProperties>
+                    <argLine>-Xms512m -Xmx1500m</argLine>
+                    <parallel>methods</parallel>
+                    <forkMode>pertest</forkMode>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <!-- attach test jar -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>2.2</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>jar</goal>
+                            <goal>test-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>build-helper-maven-plugin</artifactId>
+                <version>1.10</version>
+                <executions>
+                    <execution>
+                        <id>add_sources</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>add-source</goal>
+                        </goals>
+                        <configuration>
+                            <sources>
+                                <source>src/main/java</source>
+                            </sources>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>add_test_sources</id>
+                        <phase>generate-test-sources</phase>
+                        <goals>
+                            <goal>add-test-source</goal>
+                        </goals>
+                        <configuration>
+                            <sources>
+                                <source>src/test/java</source>
+                            </sources>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.6.1</version>
+                <configuration>
+                    {{#java8}}
+                        <source>1.8</source>
+                        <target>1.8</target>
+                    {{/java8}}
+                    {{^java8}}
+                        <source>1.7</source>
+                        <target>1.7</target>
+                    {{/java8}}
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>3.1.1</version>
+                <configuration>
+                    <doclint>none</doclint>
+                    {{#java8}}
+                        <source>1.8</source>
+                    {{/java8}}
+                    {{^java8}}
+                        <source>1.7</source>
+                    {{/java8}}
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>attach-javadocs</id>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+                <version>2.2.1</version>
+                <executions>
+                    <execution>
+                        <id>attach-sources</id>
+                        <goals>
+                            <goal>jar-no-fork</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>sign-artifacts</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-gpg-plugin</artifactId>
+                        <version>1.5</version>
+                        <executions>
+                            <execution>
+                                <id>sign-artifacts</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>sign</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.swagger</groupId>
+            <artifactId>swagger-annotations</artifactId>
+            <version>${swagger-annotations-version}</version>
+        </dependency>
+
+        <!-- @Nullable annotation -->
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+            <version>3.0.2</version>
+        </dependency>
+
+
+        <!-- HTTP client: apache client -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>${httpclient-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpmime</artifactId>
+            <version>${httpclient-version}</version>
+        </dependency>
+
+        <!-- JSON processing: jackson -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.jaxrs</groupId>
+            <artifactId>jackson-jaxrs-json-provider</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        {{#withXml}}
+
+            <!-- XML processing: Jackson -->
+            <dependency>
+                <groupId>com.fasterxml.jackson.dataformat</groupId>
+                <artifactId>jackson-dataformat-xml</artifactId>
+                <version>${jackson-version}</version>
+            </dependency>
+
+        {{/withXml}}
+        {{#joda}}
+            <dependency>
+                <groupId>com.fasterxml.jackson.datatype</groupId>
+                <artifactId>jackson-datatype-joda</artifactId>
+                <version>${jackson-version}</version>
+            </dependency>
+        {{/joda}}
+        {{#java8}}
+            <dependency>
+                <groupId>com.fasterxml.jackson.datatype</groupId>
+                <artifactId>jackson-datatype-jsr310</artifactId>
+                <version>${jackson-version}</version>
+            </dependency>
+        {{/java8}}
+        {{#threetenbp}}
+            <dependency>
+                <groupId>com.github.joschi.jackson</groupId>
+                <artifactId>jackson-datatype-threetenbp</artifactId>
+                <version>${jackson-threetenbp-version}</version>
+            </dependency>
+        {{/threetenbp}}
+        {{^java8}}
+            <!-- Base64 encoding that works in both JVM and Android -->
+            <dependency>
+                <groupId>com.brsanthu</groupId>
+                <artifactId>migbase64</artifactId>
+                <version>2.2</version>
+            </dependency>
+        {{/java8}}
+        {{#useBeanValidation}}
+            <!-- Bean Validation API support -->
+            <dependency>
+                <groupId>javax.validation</groupId>
+                <artifactId>validation-api</artifactId>
+                <version>1.1.0.Final</version>
+                <scope>provided</scope>
+            </dependency>
+        {{/useBeanValidation}}
+        {{#performBeanValidation}}
+            <!-- Bean Validation Impl. used to perform BeanValidation -->
+            <dependency>
+                <groupId>org.hibernate</groupId>
+                <artifactId>hibernate-validator</artifactId>
+                <version>5.4.1.Final</version>
+            </dependency>
+        {{/performBeanValidation}}
+        {{#parcelableModel}}
+            <!-- Needed for Parcelable support-->
+            <dependency>
+                <groupId>com.google.android</groupId>
+                <artifactId>android</artifactId>
+                <version>4.1.1.4</version>
+                <scope>provided</scope>
+            </dependency>
+        {{/parcelableModel}}
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <version>${javax-annotation-version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- test dependencies -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit-version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <swagger-annotations-version>1.5.21</swagger-annotations-version>
+        <httpclient-version>4.5.13</httpclient-version>
+        <jackson-version>2.12.1</jackson-version>
+        {{#threetenbp}}
+        <jackson-threetenbp-version>2.9.10</jackson-threetenbp-version>
+        {{/threetenbp}}
+        <javax-annotation-version>1.3.2</javax-annotation-version>
+        <maven-plugin-version>1.0.0</maven-plugin-version>
+        <junit-version>4.13.1</junit-version>
+    </properties>
+</project>

pom.xml

@@ -1339,6 +1339,7 @@
                 <module>samples/client/petstore/java/rest-assured</module>
                 <module>samples/client/petstore/java/rest-assured-jackson</module>
                 <module>samples/client/petstore/java/microprofile-rest-client</module>
+                <module>samples/client/petstore/java/apache-httpclient</module>
                 <module>samples/client/petstore/groovy</module>
                 <!-- test non-java projects -->
                 <module>samples/client/petstore/go</module>

samples/client/petstore/java/apache-httpclient/.gitignore

@@ -0,0 +1,21 @@
+*.class
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.ear
+
+# exclude jar for gradle wrapper
+!gradle/wrapper/*.jar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+# build files
+**/target
+target
+.gradle
+build

samples/client/petstore/java/apache-httpclient/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/client/petstore/java/apache-httpclient/.openapi-generator/FILES

@@ -0,0 +1,135 @@
+.gitignore
+.travis.yml
+README.md
+api/openapi.yaml
+build.gradle
+build.sbt
+docs/AdditionalPropertiesAnyType.md
+docs/AdditionalPropertiesArray.md
+docs/AdditionalPropertiesBoolean.md
+docs/AdditionalPropertiesClass.md
+docs/AdditionalPropertiesInteger.md
+docs/AdditionalPropertiesNumber.md
+docs/AdditionalPropertiesObject.md
+docs/AdditionalPropertiesString.md
+docs/Animal.md
+docs/AnotherFakeApi.md
+docs/ArrayOfArrayOfNumberOnly.md
+docs/ArrayOfNumberOnly.md
+docs/ArrayTest.md
+docs/BigCat.md
+docs/BigCatAllOf.md
+docs/Capitalization.md
+docs/Cat.md
+docs/CatAllOf.md
+docs/Category.md
+docs/ClassModel.md
+docs/Client.md
+docs/Dog.md
+docs/DogAllOf.md
+docs/EnumArrays.md
+docs/EnumClass.md
+docs/EnumTest.md
+docs/FakeApi.md
+docs/FakeClassnameTags123Api.md
+docs/FileSchemaTestClass.md
+docs/FormatTest.md
+docs/HasOnlyReadOnly.md
+docs/MapTest.md
+docs/MixedPropertiesAndAdditionalPropertiesClass.md
+docs/Model200Response.md
+docs/ModelApiResponse.md
+docs/ModelReturn.md
+docs/Name.md
+docs/NumberOnly.md
+docs/Order.md
+docs/OuterComposite.md
+docs/OuterEnum.md
+docs/Pet.md
+docs/PetApi.md
+docs/ReadOnlyFirst.md
+docs/SpecialModelName.md
+docs/StoreApi.md
+docs/Tag.md
+docs/TypeHolderDefault.md
+docs/TypeHolderExample.md
+docs/User.md
+docs/UserApi.md
+docs/XmlItem.md
+git_push.sh
+gradle.properties
+gradle/wrapper/gradle-wrapper.jar
+gradle/wrapper/gradle-wrapper.properties
+gradlew
+gradlew.bat
+pom.xml
+settings.gradle
+src/main/AndroidManifest.xml
+src/main/java/org/openapitools/client/ApiClient.java
+src/main/java/org/openapitools/client/ApiException.java
+src/main/java/org/openapitools/client/Configuration.java
+src/main/java/org/openapitools/client/CustomInstantDeserializer.java
+src/main/java/org/openapitools/client/JavaTimeFormatter.java
+src/main/java/org/openapitools/client/Pair.java
+src/main/java/org/openapitools/client/RFC3339DateFormat.java
+src/main/java/org/openapitools/client/ServerConfiguration.java
+src/main/java/org/openapitools/client/ServerVariable.java
+src/main/java/org/openapitools/client/StringUtil.java
+src/main/java/org/openapitools/client/api/AnotherFakeApi.java
+src/main/java/org/openapitools/client/api/FakeApi.java
+src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java
+src/main/java/org/openapitools/client/api/PetApi.java
+src/main/java/org/openapitools/client/api/StoreApi.java
+src/main/java/org/openapitools/client/api/UserApi.java
+src/main/java/org/openapitools/client/auth/ApiKeyAuth.java
+src/main/java/org/openapitools/client/auth/Authentication.java
+src/main/java/org/openapitools/client/auth/HttpBasicAuth.java
+src/main/java/org/openapitools/client/auth/HttpBearerAuth.java
+src/main/java/org/openapitools/client/auth/OAuth.java
+src/main/java/org/openapitools/client/auth/OAuthFlow.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+src/main/java/org/openapitools/client/model/Animal.java
+src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+src/main/java/org/openapitools/client/model/ArrayTest.java
+src/main/java/org/openapitools/client/model/BigCat.java
+src/main/java/org/openapitools/client/model/BigCatAllOf.java
+src/main/java/org/openapitools/client/model/Capitalization.java
+src/main/java/org/openapitools/client/model/Cat.java
+src/main/java/org/openapitools/client/model/CatAllOf.java
+src/main/java/org/openapitools/client/model/Category.java
+src/main/java/org/openapitools/client/model/ClassModel.java
+src/main/java/org/openapitools/client/model/Client.java
+src/main/java/org/openapitools/client/model/Dog.java
+src/main/java/org/openapitools/client/model/DogAllOf.java
+src/main/java/org/openapitools/client/model/EnumArrays.java
+src/main/java/org/openapitools/client/model/EnumClass.java
+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/MapTest.java
+src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+src/main/java/org/openapitools/client/model/Model200Response.java
+src/main/java/org/openapitools/client/model/ModelApiResponse.java
+src/main/java/org/openapitools/client/model/ModelReturn.java
+src/main/java/org/openapitools/client/model/Name.java
+src/main/java/org/openapitools/client/model/NumberOnly.java
+src/main/java/org/openapitools/client/model/Order.java
+src/main/java/org/openapitools/client/model/OuterComposite.java
+src/main/java/org/openapitools/client/model/OuterEnum.java
+src/main/java/org/openapitools/client/model/Pet.java
+src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+src/main/java/org/openapitools/client/model/SpecialModelName.java
+src/main/java/org/openapitools/client/model/Tag.java
+src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+src/main/java/org/openapitools/client/model/TypeHolderExample.java
+src/main/java/org/openapitools/client/model/User.java
+src/main/java/org/openapitools/client/model/XmlItem.java

samples/client/petstore/java/apache-httpclient/.openapi-generator/VERSION

@@ -0,0 +1 @@
+5.3.0-SNAPSHOT

samples/client/petstore/java/apache-httpclient/.travis.yml

@@ -0,0 +1,22 @@
+#
+# Generated by OpenAPI Generator: https://openapi-generator.tech
+#
+# Ref: https://docs.travis-ci.com/user/languages/java/
+#
+language: java
+jdk:
+  - openjdk12
+  - openjdk11
+  - openjdk10
+  - openjdk9
+  - openjdk8
+before_install:
+  # ensure gradlew has proper permission
+  - chmod a+x ./gradlew
+script:
+  # test using maven
+  #- mvn test
+  # test using gradle
+  - gradle test
+  # test using sbt
+  # - sbt test

samples/client/petstore/java/apache-httpclient/README.md

@@ -0,0 +1,238 @@
+# petstore-apache-httpclient
+
+OpenAPI Petstore
+
+- API version: 1.0.0
+
+This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+
+
+*Automatically generated by the [OpenAPI Generator](https://openapi-generator.tech)*
+
+## Requirements
+
+Building the API client library requires:
+
+1. Java 1.8+
+2. Maven/Gradle
+
+## Installation
+
+To install the API client library to your local Maven repository, simply execute:
+
+```shell
+mvn clean install
+```
+
+To deploy it to a remote Maven repository instead, configure the settings of the repository and execute:
+
+```shell
+mvn clean deploy
+```
+
+Refer to the [OSSRH Guide](http://central.sonatype.org/pages/ossrh-guide.html) for more information.
+
+### Maven users
+
+Add this dependency to your project's POM:
+
+```xml
+<dependency>
+  <groupId>org.openapitools</groupId>
+  <artifactId>petstore-apache-httpclient</artifactId>
+  <version>1.0.0</version>
+  <scope>compile</scope>
+</dependency>
+```
+
+### Gradle users
+
+Add this dependency to your project's build file:
+
+```groovy
+compile "org.openapitools:petstore-apache-httpclient:1.0.0"
+```
+
+### Others
+
+At first generate the JAR by executing:
+
+```shell
+mvn clean package
+```
+
+Then manually install the following JARs:
+
+- `target/petstore-apache-httpclient-1.0.0.jar`
+- `target/lib/*.jar`
+
+## Getting Started
+
+Please follow the [installation](#installation) instruction and execute the following Java code:
+
+```java
+
+import org.openapitools.client.*;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.model.*;
+import org.openapitools.client.api.AnotherFakeApi;
+
+public class AnotherFakeApiExample {
+
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        AnotherFakeApi apiInstance = new AnotherFakeApi(defaultClient);
+        Client body = new Client(); // Client | client model
+        try {
+            Client result = apiInstance.call123testSpecialTags(body);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling AnotherFakeApi#call123testSpecialTags");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+
+```
+
+## Documentation for API Endpoints
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*AnotherFakeApi* | [**call123testSpecialTags**](docs/AnotherFakeApi.md#call123testSpecialTags) | **PATCH** /another-fake/dummy | To test special tags
+*FakeApi* | [**createXmlItem**](docs/FakeApi.md#createXmlItem) | **POST** /fake/create_xml_item | creates an XmlItem
+*FakeApi* | [**fakeOuterBooleanSerialize**](docs/FakeApi.md#fakeOuterBooleanSerialize) | **POST** /fake/outer/boolean | 
+*FakeApi* | [**fakeOuterCompositeSerialize**](docs/FakeApi.md#fakeOuterCompositeSerialize) | **POST** /fake/outer/composite | 
+*FakeApi* | [**fakeOuterNumberSerialize**](docs/FakeApi.md#fakeOuterNumberSerialize) | **POST** /fake/outer/number | 
+*FakeApi* | [**fakeOuterStringSerialize**](docs/FakeApi.md#fakeOuterStringSerialize) | **POST** /fake/outer/string | 
+*FakeApi* | [**testBodyWithFileSchema**](docs/FakeApi.md#testBodyWithFileSchema) | **PUT** /fake/body-with-file-schema | 
+*FakeApi* | [**testBodyWithQueryParams**](docs/FakeApi.md#testBodyWithQueryParams) | **PUT** /fake/body-with-query-params | 
+*FakeApi* | [**testClientModel**](docs/FakeApi.md#testClientModel) | **PATCH** /fake | To test \&quot;client\&quot; model
+*FakeApi* | [**testEndpointParameters**](docs/FakeApi.md#testEndpointParameters) | **POST** /fake | Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
+*FakeApi* | [**testEnumParameters**](docs/FakeApi.md#testEnumParameters) | **GET** /fake | To test enum parameters
+*FakeApi* | [**testGroupParameters**](docs/FakeApi.md#testGroupParameters) | **DELETE** /fake | Fake endpoint to test group parameters (optional)
+*FakeApi* | [**testInlineAdditionalProperties**](docs/FakeApi.md#testInlineAdditionalProperties) | **POST** /fake/inline-additionalProperties | test inline additionalProperties
+*FakeApi* | [**testJsonFormData**](docs/FakeApi.md#testJsonFormData) | **GET** /fake/jsonFormData | test json serialization of form data
+*FakeApi* | [**testQueryParameterCollectionFormat**](docs/FakeApi.md#testQueryParameterCollectionFormat) | **PUT** /fake/test-query-paramters | 
+*FakeClassnameTags123Api* | [**testClassname**](docs/FakeClassnameTags123Api.md#testClassname) | **PATCH** /fake_classname_test | To test class name in snake case
+*PetApi* | [**addPet**](docs/PetApi.md#addPet) | **POST** /pet | Add a new pet to the store
+*PetApi* | [**deletePet**](docs/PetApi.md#deletePet) | **DELETE** /pet/{petId} | Deletes a pet
+*PetApi* | [**findPetsByStatus**](docs/PetApi.md#findPetsByStatus) | **GET** /pet/findByStatus | Finds Pets by status
+*PetApi* | [**findPetsByTags**](docs/PetApi.md#findPetsByTags) | **GET** /pet/findByTags | Finds Pets by tags
+*PetApi* | [**getPetById**](docs/PetApi.md#getPetById) | **GET** /pet/{petId} | Find pet by ID
+*PetApi* | [**updatePet**](docs/PetApi.md#updatePet) | **PUT** /pet | Update an existing pet
+*PetApi* | [**updatePetWithForm**](docs/PetApi.md#updatePetWithForm) | **POST** /pet/{petId} | Updates a pet in the store with form data
+*PetApi* | [**uploadFile**](docs/PetApi.md#uploadFile) | **POST** /pet/{petId}/uploadImage | uploads an image
+*PetApi* | [**uploadFileWithRequiredFile**](docs/PetApi.md#uploadFileWithRequiredFile) | **POST** /fake/{petId}/uploadImageWithRequiredFile | uploads an image (required)
+*StoreApi* | [**deleteOrder**](docs/StoreApi.md#deleteOrder) | **DELETE** /store/order/{order_id} | Delete purchase order by ID
+*StoreApi* | [**getInventory**](docs/StoreApi.md#getInventory) | **GET** /store/inventory | Returns pet inventories by status
+*StoreApi* | [**getOrderById**](docs/StoreApi.md#getOrderById) | **GET** /store/order/{order_id} | Find purchase order by ID
+*StoreApi* | [**placeOrder**](docs/StoreApi.md#placeOrder) | **POST** /store/order | Place an order for a pet
+*UserApi* | [**createUser**](docs/UserApi.md#createUser) | **POST** /user | Create user
+*UserApi* | [**createUsersWithArrayInput**](docs/UserApi.md#createUsersWithArrayInput) | **POST** /user/createWithArray | Creates list of users with given input array
+*UserApi* | [**createUsersWithListInput**](docs/UserApi.md#createUsersWithListInput) | **POST** /user/createWithList | Creates list of users with given input array
+*UserApi* | [**deleteUser**](docs/UserApi.md#deleteUser) | **DELETE** /user/{username} | Delete user
+*UserApi* | [**getUserByName**](docs/UserApi.md#getUserByName) | **GET** /user/{username} | Get user by user name
+*UserApi* | [**loginUser**](docs/UserApi.md#loginUser) | **GET** /user/login | Logs user into the system
+*UserApi* | [**logoutUser**](docs/UserApi.md#logoutUser) | **GET** /user/logout | Logs out current logged in user session
+*UserApi* | [**updateUser**](docs/UserApi.md#updateUser) | **PUT** /user/{username} | Updated user
+
+
+## Documentation for Models
+
+ - [AdditionalPropertiesAnyType](docs/AdditionalPropertiesAnyType.md)
+ - [AdditionalPropertiesArray](docs/AdditionalPropertiesArray.md)
+ - [AdditionalPropertiesBoolean](docs/AdditionalPropertiesBoolean.md)
+ - [AdditionalPropertiesClass](docs/AdditionalPropertiesClass.md)
+ - [AdditionalPropertiesInteger](docs/AdditionalPropertiesInteger.md)
+ - [AdditionalPropertiesNumber](docs/AdditionalPropertiesNumber.md)
+ - [AdditionalPropertiesObject](docs/AdditionalPropertiesObject.md)
+ - [AdditionalPropertiesString](docs/AdditionalPropertiesString.md)
+ - [Animal](docs/Animal.md)
+ - [ArrayOfArrayOfNumberOnly](docs/ArrayOfArrayOfNumberOnly.md)
+ - [ArrayOfNumberOnly](docs/ArrayOfNumberOnly.md)
+ - [ArrayTest](docs/ArrayTest.md)
+ - [BigCat](docs/BigCat.md)
+ - [BigCatAllOf](docs/BigCatAllOf.md)
+ - [Capitalization](docs/Capitalization.md)
+ - [Cat](docs/Cat.md)
+ - [CatAllOf](docs/CatAllOf.md)
+ - [Category](docs/Category.md)
+ - [ClassModel](docs/ClassModel.md)
+ - [Client](docs/Client.md)
+ - [Dog](docs/Dog.md)
+ - [DogAllOf](docs/DogAllOf.md)
+ - [EnumArrays](docs/EnumArrays.md)
+ - [EnumClass](docs/EnumClass.md)
+ - [EnumTest](docs/EnumTest.md)
+ - [FileSchemaTestClass](docs/FileSchemaTestClass.md)
+ - [FormatTest](docs/FormatTest.md)
+ - [HasOnlyReadOnly](docs/HasOnlyReadOnly.md)
+ - [MapTest](docs/MapTest.md)
+ - [MixedPropertiesAndAdditionalPropertiesClass](docs/MixedPropertiesAndAdditionalPropertiesClass.md)
+ - [Model200Response](docs/Model200Response.md)
+ - [ModelApiResponse](docs/ModelApiResponse.md)
+ - [ModelReturn](docs/ModelReturn.md)
+ - [Name](docs/Name.md)
+ - [NumberOnly](docs/NumberOnly.md)
+ - [Order](docs/Order.md)
+ - [OuterComposite](docs/OuterComposite.md)
+ - [OuterEnum](docs/OuterEnum.md)
+ - [Pet](docs/Pet.md)
+ - [ReadOnlyFirst](docs/ReadOnlyFirst.md)
+ - [SpecialModelName](docs/SpecialModelName.md)
+ - [Tag](docs/Tag.md)
+ - [TypeHolderDefault](docs/TypeHolderDefault.md)
+ - [TypeHolderExample](docs/TypeHolderExample.md)
+ - [User](docs/User.md)
+ - [XmlItem](docs/XmlItem.md)
+
+
+## Documentation for Authorization
+
+Authentication schemes defined for the API:
+### api_key
+
+
+- **Type**: API key
+- **API key parameter name**: api_key
+- **Location**: HTTP header
+
+### api_key_query
+
+
+- **Type**: API key
+- **API key parameter name**: api_key_query
+- **Location**: URL query string
+
+### http_basic_test
+
+
+- **Type**: HTTP basic authentication
+
+### petstore_auth
+
+
+- **Type**: OAuth
+- **Flow**: implicit
+- **Authorization URL**: http://petstore.swagger.io/api/oauth/dialog
+- **Scopes**: 
+  - write:pets: modify pets in your account
+  - read:pets: read your pets
+
+
+## Recommendation
+
+It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issues.
+
+## Author
+
+
+

samples/client/petstore/java/apache-httpclient/build.gradle

@@ -0,0 +1,138 @@
+apply plugin: 'idea'
+apply plugin: 'eclipse'
+
+group = 'org.openapitools'
+version = '1.0.0'
+
+buildscript {
+    repositories {
+        maven { url "https://repo1.maven.org/maven2" }
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:2.3.+'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
+    }
+}
+
+repositories {
+    maven { url "https://repo1.maven.org/maven2" }
+    jcenter()
+}
+
+if(hasProperty('target') && target == 'android') {
+
+    apply plugin: 'com.android.library'
+    apply plugin: 'com.github.dcendents.android-maven'
+
+    android {
+        compileSdkVersion 25
+        buildToolsVersion '25.0.2'
+        defaultConfig {
+            minSdkVersion 14
+            targetSdkVersion 25
+        }
+
+        compileOptions {
+            sourceCompatibility JavaVersion.VERSION_1_8
+            targetCompatibility JavaVersion.VERSION_1_8
+        }
+
+        // Rename the aar correctly
+        libraryVariants.all { variant ->
+            variant.outputs.each { output ->
+                def outputFile = output.outputFile
+                if (outputFile != null && outputFile.name.endsWith('.aar')) {
+                    def fileName = "${project.name}-${variant.baseName}-${version}.aar"
+                    output.outputFile = new File(outputFile.parent, fileName)
+                }
+            }
+        }
+
+        dependencies {
+            provided 'javax.annotation:jsr250-api:1.0'
+        }
+    }
+
+    afterEvaluate {
+        android.libraryVariants.all { variant ->
+            def task = project.tasks.create "jar${variant.name.capitalize()}", Jar
+            task.description = "Create jar artifact for ${variant.name}"
+            task.dependsOn variant.javaCompile
+            task.from variant.javaCompile.destinationDir
+            task.destinationDir = project.file("${project.buildDir}/outputs/jar")
+            task.archiveName = "${project.name}-${variant.baseName}-${version}.jar"
+            artifacts.add('archives', task);
+        }
+    }
+
+    task sourcesJar(type: Jar) {
+        from android.sourceSets.main.java.srcDirs
+        classifier = 'sources'
+    }
+
+    artifacts {
+        archives sourcesJar
+    }
+
+} else {
+
+    apply plugin: 'java'
+    apply plugin: 'maven'
+
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+
+    install {
+        repositories.mavenInstaller {
+            pom.artifactId = 'petstore-apache-httpclient'
+        }
+    }
+
+    task execute(type:JavaExec) {
+       main = System.getProperty('mainClass')
+       classpath = sourceSets.main.runtimeClasspath
+    }
+
+    task sourcesJar(type: Jar, dependsOn: classes) {
+        classifier = 'sources'
+        from sourceSets.main.allSource
+    }
+
+    task javadocJar(type: Jar, dependsOn: javadoc) {
+        classifier = 'javadoc'
+        from javadoc.destinationDir
+    }
+
+    artifacts {
+        archives sourcesJar
+        archives javadocJar
+    }
+}
+
+ext {
+    swagger_annotations_version = "1.5.22"
+    jackson_version = "2.12.1"
+    jackson_databind_version = "2.10.5.1"
+    jackson_databind_nullable_version = "0.2.1"
+    jackson_threetenbp_version = "2.9.10"
+    jersey_version = "1.19.4"
+    jodatime_version = "2.9.9"
+    junit_version = "4.13.1"
+}
+
+dependencies {
+    implementation "io.swagger:swagger-annotations:$swagger_annotations_version"
+    implementation "com.google.code.findbugs:jsr305:3.0.2"
+    implementation "com.sun.jersey:jersey-client:$jersey_version"
+    implementation "com.sun.jersey.contribs:jersey-multipart:$jersey_version"
+    implementation "com.fasterxml.jackson.core:jackson-core:$jackson_version"
+    implementation "com.fasterxml.jackson.core:jackson-annotations:$jackson_version"
+    implementation "com.fasterxml.jackson.core:jackson-databind:$jackson_databind_version"
+    implementation "com.fasterxml.jackson.jaxrs:jackson-jaxrs-json-provider:$jackson_version"
+    implementation "org.openapitools:jackson-databind-nullable:$jackson_databind_nullable_version"
+    implementation "com.fasterxml.jackson.datatype:jackson-datatype-jsr310:$jackson_version"
+    implementation "com.github.joschi.jackson:jackson-datatype-threetenbp:$jackson_threetenbp_version"
+    implementation 'javax.annotation:javax.annotation-api:1.3.2'
+    testImplementation "junit:junit:$junit_version"
+}

samples/client/petstore/java/apache-httpclient/build.sbt

@@ -0,0 +1 @@
+# TODO

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesAnyType.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesAnyType
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesArray.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesArray
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesBoolean.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesBoolean
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesClass.md

@@ -0,0 +1,23 @@
+
+
+# AdditionalPropertiesClass
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**mapString** | **Map<String, String>** |  |  [optional]
+**mapNumber** | **Map<String, BigDecimal>** |  |  [optional]
+**mapInteger** | **Map<String, Integer>** |  |  [optional]
+**mapBoolean** | **Map<String, Boolean>** |  |  [optional]
+**mapArrayInteger** | **Map<String, List<Integer>>** |  |  [optional]
+**mapArrayAnytype** | **Map<String, List<Object>>** |  |  [optional]
+**mapMapString** | **Map<String, Map<String, String>>** |  |  [optional]
+**mapMapAnytype** | **Map<String, Map<String, Object>>** |  |  [optional]
+**anytype1** | **Object** |  |  [optional]
+**anytype2** | **Object** |  |  [optional]
+**anytype3** | **Object** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesInteger.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesInteger
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesNumber.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesNumber
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesObject.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesObject
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AdditionalPropertiesString.md

@@ -0,0 +1,13 @@
+
+
+# AdditionalPropertiesString
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Animal.md

@@ -0,0 +1,14 @@
+
+
+# Animal
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**className** | **String** |  | 
+**color** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/AnotherFakeApi.md

@@ -0,0 +1,75 @@
+# AnotherFakeApi
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**call123testSpecialTags**](AnotherFakeApi.md#call123testSpecialTags) | **PATCH** /another-fake/dummy | To test special tags
+
+
+
+## call123testSpecialTags
+
+> Client call123testSpecialTags(body)
+
+To test special tags
+
+To test special tags and operation ID starting with number
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.AnotherFakeApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        AnotherFakeApi apiInstance = new AnotherFakeApi(defaultClient);
+        Client body = new Client(); // Client | client model
+        try {
+            Client result = apiInstance.call123testSpecialTags(body);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling AnotherFakeApi#call123testSpecialTags");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Client**](Client.md)| client model |
+
+### Return type
+
+[**Client**](Client.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+

samples/client/petstore/java/apache-httpclient/docs/ArrayOfArrayOfNumberOnly.md

@@ -0,0 +1,13 @@
+
+
+# ArrayOfArrayOfNumberOnly
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**arrayArrayNumber** | **List<List<BigDecimal>>** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/ArrayOfNumberOnly.md

@@ -0,0 +1,13 @@
+
+
+# ArrayOfNumberOnly
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**arrayNumber** | **List<BigDecimal>** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/ArrayTest.md

@@ -0,0 +1,15 @@
+
+
+# ArrayTest
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**arrayOfString** | **List<String>** |  |  [optional]
+**arrayArrayOfInteger** | **List<List<Long>>** |  |  [optional]
+**arrayArrayOfModel** | **List<List<ReadOnlyFirst>>** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/BigCat.md

@@ -0,0 +1,24 @@
+
+
+# BigCat
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**kind** | [**KindEnum**](#KindEnum) |  |  [optional]
+
+
+
+## Enum: KindEnum
+
+Name | Value
+---- | -----
+LIONS | "lions"
+TIGERS | "tigers"
+LEOPARDS | "leopards"
+JAGUARS | "jaguars"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/BigCatAllOf.md

@@ -0,0 +1,24 @@
+
+
+# BigCatAllOf
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**kind** | [**KindEnum**](#KindEnum) |  |  [optional]
+
+
+
+## Enum: KindEnum
+
+Name | Value
+---- | -----
+LIONS | "lions"
+TIGERS | "tigers"
+LEOPARDS | "leopards"
+JAGUARS | "jaguars"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Capitalization.md

@@ -0,0 +1,18 @@
+
+
+# Capitalization
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**smallCamel** | **String** |  |  [optional]
+**capitalCamel** | **String** |  |  [optional]
+**smallSnake** | **String** |  |  [optional]
+**capitalSnake** | **String** |  |  [optional]
+**scAETHFlowPoints** | **String** |  |  [optional]
+**ATT_NAME** | **String** | Name of the pet  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Cat.md

@@ -0,0 +1,13 @@
+
+
+# Cat
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**declawed** | **Boolean** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/CatAllOf.md

@@ -0,0 +1,13 @@
+
+
+# CatAllOf
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**declawed** | **Boolean** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Category.md

@@ -0,0 +1,14 @@
+
+
+# Category
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **Long** |  |  [optional]
+**name** | **String** |  | 
+
+
+

samples/client/petstore/java/apache-httpclient/docs/ClassModel.md

@@ -0,0 +1,14 @@
+
+
+# ClassModel
+
+Model for testing model with \"_class\" property
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**propertyClass** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Client.md

@@ -0,0 +1,13 @@
+
+
+# Client
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**client** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Dog.md

@@ -0,0 +1,13 @@
+
+
+# Dog
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**breed** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/DogAllOf.md

@@ -0,0 +1,13 @@
+
+
+# DogAllOf
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**breed** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/EnumArrays.md

@@ -0,0 +1,32 @@
+
+
+# EnumArrays
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**justSymbol** | [**JustSymbolEnum**](#JustSymbolEnum) |  |  [optional]
+**arrayEnum** | [**List<ArrayEnumEnum>**](#List<ArrayEnumEnum>) |  |  [optional]
+
+
+
+## Enum: JustSymbolEnum
+
+Name | Value
+---- | -----
+GREATER_THAN_OR_EQUAL_TO | ">="
+DOLLAR | "$"
+
+
+
+## Enum: List<ArrayEnumEnum>
+
+Name | Value
+---- | -----
+FISH | "fish"
+CRAB | "crab"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/EnumClass.md

@@ -0,0 +1,15 @@
+
+
+# EnumClass
+
+## Enum
+
+
+* `_ABC` (value: `"_abc"`)
+
+* `_EFG` (value: `"-efg"`)
+
+* `_XYZ_` (value: `"(xyz)"`)
+
+
+

samples/client/petstore/java/apache-httpclient/docs/EnumTest.md

@@ -0,0 +1,55 @@
+
+
+# EnumTest
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**enumString** | [**EnumStringEnum**](#EnumStringEnum) |  |  [optional]
+**enumStringRequired** | [**EnumStringRequiredEnum**](#EnumStringRequiredEnum) |  | 
+**enumInteger** | [**EnumIntegerEnum**](#EnumIntegerEnum) |  |  [optional]
+**enumNumber** | [**EnumNumberEnum**](#EnumNumberEnum) |  |  [optional]
+**outerEnum** | **OuterEnum** |  |  [optional]
+
+
+
+## Enum: EnumStringEnum
+
+Name | Value
+---- | -----
+UPPER | "UPPER"
+LOWER | "lower"
+EMPTY | ""
+
+
+
+## Enum: EnumStringRequiredEnum
+
+Name | Value
+---- | -----
+UPPER | "UPPER"
+LOWER | "lower"
+EMPTY | ""
+
+
+
+## Enum: EnumIntegerEnum
+
+Name | Value
+---- | -----
+NUMBER_1 | 1
+NUMBER_MINUS_1 | -1
+
+
+
+## Enum: EnumNumberEnum
+
+Name | Value
+---- | -----
+NUMBER_1_DOT_1 | 1.1
+NUMBER_MINUS_1_DOT_2 | -1.2
+
+
+

samples/client/petstore/java/apache-httpclient/docs/FakeClassnameTags123Api.md

@@ -0,0 +1,82 @@
+# FakeClassnameTags123Api
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**testClassname**](FakeClassnameTags123Api.md#testClassname) | **PATCH** /fake_classname_test | To test class name in snake case
+
+
+
+## testClassname
+
+> Client testClassname(body)
+
+To test class name in snake case
+
+To test class name in snake case
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.FakeClassnameTags123Api;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure API key authorization: api_key_query
+        ApiKeyAuth api_key_query = (ApiKeyAuth) defaultClient.getAuthentication("api_key_query");
+        api_key_query.setApiKey("YOUR API KEY");
+        // Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+        //api_key_query.setApiKeyPrefix("Token");
+
+        FakeClassnameTags123Api apiInstance = new FakeClassnameTags123Api(defaultClient);
+        Client body = new Client(); // Client | client model
+        try {
+            Client result = apiInstance.testClassname(body);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling FakeClassnameTags123Api#testClassname");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Client**](Client.md)| client model |
+
+### Return type
+
+[**Client**](Client.md)
+
+### Authorization
+
+[api_key_query](../README.md#api_key_query)
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+

samples/client/petstore/java/apache-httpclient/docs/FileSchemaTestClass.md

@@ -0,0 +1,14 @@
+
+
+# FileSchemaTestClass
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**file** | [**java.io.File**](java.io.File.md) |  |  [optional]
+**files** | [**List<java.io.File>**](java.io.File.md) |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/FormatTest.md

@@ -0,0 +1,26 @@
+
+
+# FormatTest
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**integer** | **Integer** |  |  [optional]
+**int32** | **Integer** |  |  [optional]
+**int64** | **Long** |  |  [optional]
+**number** | **BigDecimal** |  | 
+**_float** | **Float** |  |  [optional]
+**_double** | **Double** |  |  [optional]
+**string** | **String** |  |  [optional]
+**_byte** | **byte[]** |  | 
+**binary** | **File** |  |  [optional]
+**date** | **LocalDate** |  | 
+**dateTime** | **OffsetDateTime** |  |  [optional]
+**uuid** | **UUID** |  |  [optional]
+**password** | **String** |  | 
+**bigDecimal** | **BigDecimal** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/HasOnlyReadOnly.md

@@ -0,0 +1,14 @@
+
+
+# HasOnlyReadOnly
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**bar** | **String** |  |  [optional] [readonly]
+**foo** | **String** |  |  [optional] [readonly]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/MapTest.md

@@ -0,0 +1,25 @@
+
+
+# MapTest
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**mapMapOfString** | **Map<String, Map<String, String>>** |  |  [optional]
+**mapOfEnumString** | [**Map<String, InnerEnum>**](#Map<String, InnerEnum>) |  |  [optional]
+**directMap** | **Map<String, Boolean>** |  |  [optional]
+**indirectMap** | **Map<String, Boolean>** |  |  [optional]
+
+
+
+## Enum: Map<String, InnerEnum>
+
+Name | Value
+---- | -----
+UPPER | "UPPER"
+LOWER | "lower"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/MixedPropertiesAndAdditionalPropertiesClass.md

@@ -0,0 +1,15 @@
+
+
+# MixedPropertiesAndAdditionalPropertiesClass
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**uuid** | **UUID** |  |  [optional]
+**dateTime** | **OffsetDateTime** |  |  [optional]
+**map** | [**Map<String, Animal>**](Animal.md) |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Model200Response.md

@@ -0,0 +1,15 @@
+
+
+# Model200Response
+
+Model for testing model name starting with number
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **Integer** |  |  [optional]
+**propertyClass** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/ModelApiResponse.md

@@ -0,0 +1,15 @@
+
+
+# ModelApiResponse
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**code** | **Integer** |  |  [optional]
+**type** | **String** |  |  [optional]
+**message** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/ModelReturn.md

@@ -0,0 +1,14 @@
+
+
+# ModelReturn
+
+Model for testing reserved words
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**_return** | **Integer** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Name.md

@@ -0,0 +1,17 @@
+
+
+# Name
+
+Model for testing model name same as property name
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**name** | **Integer** |  | 
+**snakeCase** | **Integer** |  |  [optional] [readonly]
+**property** | **String** |  |  [optional]
+**_123number** | **Integer** |  |  [optional] [readonly]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/NumberOnly.md

@@ -0,0 +1,13 @@
+
+
+# NumberOnly
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**justNumber** | **BigDecimal** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Order.md

@@ -0,0 +1,28 @@
+
+
+# Order
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **Long** |  |  [optional]
+**petId** | **Long** |  |  [optional]
+**quantity** | **Integer** |  |  [optional]
+**shipDate** | **OffsetDateTime** |  |  [optional]
+**status** | [**StatusEnum**](#StatusEnum) | Order Status |  [optional]
+**complete** | **Boolean** |  |  [optional]
+
+
+
+## Enum: StatusEnum
+
+Name | Value
+---- | -----
+PLACED | "placed"
+APPROVED | "approved"
+DELIVERED | "delivered"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/OuterComposite.md

@@ -0,0 +1,15 @@
+
+
+# OuterComposite
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**myNumber** | **BigDecimal** |  |  [optional]
+**myString** | **String** |  |  [optional]
+**myBoolean** | **Boolean** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/OuterEnum.md

@@ -0,0 +1,15 @@
+
+
+# OuterEnum
+
+## Enum
+
+
+* `PLACED` (value: `"placed"`)
+
+* `APPROVED` (value: `"approved"`)
+
+* `DELIVERED` (value: `"delivered"`)
+
+
+

samples/client/petstore/java/apache-httpclient/docs/Pet.md

@@ -0,0 +1,28 @@
+
+
+# Pet
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **Long** |  |  [optional]
+**category** | [**Category**](Category.md) |  |  [optional]
+**name** | **String** |  | 
+**photoUrls** | **Set<String>** |  | 
+**tags** | [**List<Tag>**](Tag.md) |  |  [optional]
+**status** | [**StatusEnum**](#StatusEnum) | pet status in the store |  [optional]
+
+
+
+## Enum: StatusEnum
+
+Name | Value
+---- | -----
+AVAILABLE | "available"
+PENDING | "pending"
+SOLD | "sold"
+
+
+

samples/client/petstore/java/apache-httpclient/docs/PetApi.md

@@ -0,0 +1,665 @@
+# PetApi
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**addPet**](PetApi.md#addPet) | **POST** /pet | Add a new pet to the store
+[**deletePet**](PetApi.md#deletePet) | **DELETE** /pet/{petId} | Deletes a pet
+[**findPetsByStatus**](PetApi.md#findPetsByStatus) | **GET** /pet/findByStatus | Finds Pets by status
+[**findPetsByTags**](PetApi.md#findPetsByTags) | **GET** /pet/findByTags | Finds Pets by tags
+[**getPetById**](PetApi.md#getPetById) | **GET** /pet/{petId} | Find pet by ID
+[**updatePet**](PetApi.md#updatePet) | **PUT** /pet | Update an existing pet
+[**updatePetWithForm**](PetApi.md#updatePetWithForm) | **POST** /pet/{petId} | Updates a pet in the store with form data
+[**uploadFile**](PetApi.md#uploadFile) | **POST** /pet/{petId}/uploadImage | uploads an image
+[**uploadFileWithRequiredFile**](PetApi.md#uploadFileWithRequiredFile) | **POST** /fake/{petId}/uploadImageWithRequiredFile | uploads an image (required)
+
+
+
+## addPet
+
+> addPet(body)
+
+Add a new pet to the store
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Pet body = new Pet(); // Pet | Pet object that needs to be added to the store
+        try {
+            apiInstance.addPet(body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#addPet");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Pet**](Pet.md)| Pet object that needs to be added to the store |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: application/json, application/xml
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **405** | Invalid input |  -  |
+
+
+## deletePet
+
+> deletePet(petId, apiKey)
+
+Deletes a pet
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Long petId = 56L; // Long | Pet id to delete
+        String apiKey = "apiKey_example"; // String | 
+        try {
+            apiInstance.deletePet(petId, apiKey);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#deletePet");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **Long**| Pet id to delete |
+ **apiKey** | **String**|  | [optional]
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid pet value |  -  |
+
+
+## findPetsByStatus
+
+> List<Pet> findPetsByStatus(status)
+
+Finds Pets by status
+
+Multiple status values can be provided with comma separated strings
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        List<String> status = Arrays.asList("available"); // List<String> | Status values that need to be considered for filter
+        try {
+            List<Pet> result = apiInstance.findPetsByStatus(status);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#findPetsByStatus");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **status** | [**List&lt;String&gt;**](String.md)| Status values that need to be considered for filter | [enum: available, pending, sold]
+
+### Return type
+
+[**List&lt;Pet&gt;**](Pet.md)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid status value |  -  |
+
+
+## findPetsByTags
+
+> Set&lt;Pet&gt; findPetsByTags(tags)
+
+Finds Pets by tags
+
+Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Set<String> tags = Arrays.asList(); // Set<String> | Tags to filter by
+        try {
+            Set<Pet> result = apiInstance.findPetsByTags(tags);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#findPetsByTags");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **tags** | [**Set&lt;String&gt;**](String.md)| Tags to filter by |
+
+### Return type
+
+[**Set&lt;Pet&gt;**](Pet.md)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid tag value |  -  |
+
+
+## getPetById
+
+> Pet getPetById(petId)
+
+Find pet by ID
+
+Returns a single pet
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure API key authorization: api_key
+        ApiKeyAuth api_key = (ApiKeyAuth) defaultClient.getAuthentication("api_key");
+        api_key.setApiKey("YOUR API KEY");
+        // Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+        //api_key.setApiKeyPrefix("Token");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Long petId = 56L; // Long | ID of pet to return
+        try {
+            Pet result = apiInstance.getPetById(petId);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#getPetById");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **Long**| ID of pet to return |
+
+### Return type
+
+[**Pet**](Pet.md)
+
+### Authorization
+
+[api_key](../README.md#api_key)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid ID supplied |  -  |
+| **404** | Pet not found |  -  |
+
+
+## updatePet
+
+> updatePet(body)
+
+Update an existing pet
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Pet body = new Pet(); // Pet | Pet object that needs to be added to the store
+        try {
+            apiInstance.updatePet(body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#updatePet");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Pet**](Pet.md)| Pet object that needs to be added to the store |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: application/json, application/xml
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid ID supplied |  -  |
+| **404** | Pet not found |  -  |
+| **405** | Validation exception |  -  |
+
+
+## updatePetWithForm
+
+> updatePetWithForm(petId, name, status)
+
+Updates a pet in the store with form data
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Long petId = 56L; // Long | ID of pet that needs to be updated
+        String name = "name_example"; // String | Updated name of the pet
+        String status = "status_example"; // String | Updated status of the pet
+        try {
+            apiInstance.updatePetWithForm(petId, name, status);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#updatePetWithForm");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **Long**| ID of pet that needs to be updated |
+ **name** | **String**| Updated name of the pet | [optional]
+ **status** | **String**| Updated status of the pet | [optional]
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: application/x-www-form-urlencoded
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **405** | Invalid input |  -  |
+
+
+## uploadFile
+
+> ModelApiResponse uploadFile(petId, additionalMetadata, file)
+
+uploads an image
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Long petId = 56L; // Long | ID of pet to update
+        String additionalMetadata = "additionalMetadata_example"; // String | Additional data to pass to server
+        File file = new File("/path/to/file"); // File | file to upload
+        try {
+            ModelApiResponse result = apiInstance.uploadFile(petId, additionalMetadata, file);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#uploadFile");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **Long**| ID of pet to update |
+ **additionalMetadata** | **String**| Additional data to pass to server | [optional]
+ **file** | **File**| file to upload | [optional]
+
+### Return type
+
+[**ModelApiResponse**](ModelApiResponse.md)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: multipart/form-data
+- **Accept**: application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+
+## uploadFileWithRequiredFile
+
+> ModelApiResponse uploadFileWithRequiredFile(petId, requiredFile, additionalMetadata)
+
+uploads an image (required)
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.PetApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure OAuth2 access token for authorization: petstore_auth
+        OAuth petstore_auth = (OAuth) defaultClient.getAuthentication("petstore_auth");
+        petstore_auth.setAccessToken("YOUR ACCESS TOKEN");
+
+        PetApi apiInstance = new PetApi(defaultClient);
+        Long petId = 56L; // Long | ID of pet to update
+        File requiredFile = new File("/path/to/file"); // File | file to upload
+        String additionalMetadata = "additionalMetadata_example"; // String | Additional data to pass to server
+        try {
+            ModelApiResponse result = apiInstance.uploadFileWithRequiredFile(petId, requiredFile, additionalMetadata);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling PetApi#uploadFileWithRequiredFile");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **petId** | **Long**| ID of pet to update |
+ **requiredFile** | **File**| file to upload |
+ **additionalMetadata** | **String**| Additional data to pass to server | [optional]
+
+### Return type
+
+[**ModelApiResponse**](ModelApiResponse.md)
+
+### Authorization
+
+[petstore_auth](../README.md#petstore_auth)
+
+### HTTP request headers
+
+- **Content-Type**: multipart/form-data
+- **Accept**: application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+

samples/client/petstore/java/apache-httpclient/docs/ReadOnlyFirst.md

@@ -0,0 +1,14 @@
+
+
+# ReadOnlyFirst
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**bar** | **String** |  |  [optional] [readonly]
+**baz** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/SpecialModelName.md

@@ -0,0 +1,13 @@
+
+
+# SpecialModelName
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**$specialPropertyName** | **Long** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/StoreApi.md

@@ -0,0 +1,280 @@
+# StoreApi
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**deleteOrder**](StoreApi.md#deleteOrder) | **DELETE** /store/order/{order_id} | Delete purchase order by ID
+[**getInventory**](StoreApi.md#getInventory) | **GET** /store/inventory | Returns pet inventories by status
+[**getOrderById**](StoreApi.md#getOrderById) | **GET** /store/order/{order_id} | Find purchase order by ID
+[**placeOrder**](StoreApi.md#placeOrder) | **POST** /store/order | Place an order for a pet
+
+
+
+## deleteOrder
+
+> deleteOrder(orderId)
+
+Delete purchase order by ID
+
+For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.StoreApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        StoreApi apiInstance = new StoreApi(defaultClient);
+        String orderId = "orderId_example"; // String | ID of the order that needs to be deleted
+        try {
+            apiInstance.deleteOrder(orderId);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling StoreApi#deleteOrder");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **orderId** | **String**| ID of the order that needs to be deleted |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **400** | Invalid ID supplied |  -  |
+| **404** | Order not found |  -  |
+
+
+## getInventory
+
+> Map<String, Integer> getInventory()
+
+Returns pet inventories by status
+
+Returns a map of status codes to quantities
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.auth.*;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.StoreApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+        
+        // Configure API key authorization: api_key
+        ApiKeyAuth api_key = (ApiKeyAuth) defaultClient.getAuthentication("api_key");
+        api_key.setApiKey("YOUR API KEY");
+        // Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
+        //api_key.setApiKeyPrefix("Token");
+
+        StoreApi apiInstance = new StoreApi(defaultClient);
+        try {
+            Map<String, Integer> result = apiInstance.getInventory();
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling StoreApi#getInventory");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+**Map&lt;String, Integer&gt;**
+
+### Authorization
+
+[api_key](../README.md#api_key)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+
+
+## getOrderById
+
+> Order getOrderById(orderId)
+
+Find purchase order by ID
+
+For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.StoreApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        StoreApi apiInstance = new StoreApi(defaultClient);
+        Long orderId = 56L; // Long | ID of pet that needs to be fetched
+        try {
+            Order result = apiInstance.getOrderById(orderId);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling StoreApi#getOrderById");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **orderId** | **Long**| ID of pet that needs to be fetched |
+
+### Return type
+
+[**Order**](Order.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid ID supplied |  -  |
+| **404** | Order not found |  -  |
+
+
+## placeOrder
+
+> Order placeOrder(body)
+
+Place an order for a pet
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.StoreApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        StoreApi apiInstance = new StoreApi(defaultClient);
+        Order body = new Order(); // Order | order placed for purchasing the pet
+        try {
+            Order result = apiInstance.placeOrder(body);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling StoreApi#placeOrder");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**Order**](Order.md)| order placed for purchasing the pet |
+
+### Return type
+
+[**Order**](Order.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid Order |  -  |
+

samples/client/petstore/java/apache-httpclient/docs/Tag.md

@@ -0,0 +1,14 @@
+
+
+# Tag
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **Long** |  |  [optional]
+**name** | **String** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/TypeHolderDefault.md

@@ -0,0 +1,17 @@
+
+
+# TypeHolderDefault
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**stringItem** | **String** |  | 
+**numberItem** | **BigDecimal** |  | 
+**integerItem** | **Integer** |  | 
+**boolItem** | **Boolean** |  | 
+**arrayItem** | **List<Integer>** |  | 
+
+
+

samples/client/petstore/java/apache-httpclient/docs/TypeHolderExample.md

@@ -0,0 +1,18 @@
+
+
+# TypeHolderExample
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**stringItem** | **String** |  | 
+**numberItem** | **BigDecimal** |  | 
+**floatItem** | **Float** |  | 
+**integerItem** | **Integer** |  | 
+**boolItem** | **Boolean** |  | 
+**arrayItem** | **List<Integer>** |  | 
+
+
+

samples/client/petstore/java/apache-httpclient/docs/User.md

@@ -0,0 +1,20 @@
+
+
+# User
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | **Long** |  |  [optional]
+**username** | **String** |  |  [optional]
+**firstName** | **String** |  |  [optional]
+**lastName** | **String** |  |  [optional]
+**email** | **String** |  |  [optional]
+**password** | **String** |  |  [optional]
+**phone** | **String** |  |  [optional]
+**userStatus** | **Integer** | User Status |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/docs/UserApi.md

@@ -0,0 +1,533 @@
+# UserApi
+
+All URIs are relative to *http://petstore.swagger.io:80/v2*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**createUser**](UserApi.md#createUser) | **POST** /user | Create user
+[**createUsersWithArrayInput**](UserApi.md#createUsersWithArrayInput) | **POST** /user/createWithArray | Creates list of users with given input array
+[**createUsersWithListInput**](UserApi.md#createUsersWithListInput) | **POST** /user/createWithList | Creates list of users with given input array
+[**deleteUser**](UserApi.md#deleteUser) | **DELETE** /user/{username} | Delete user
+[**getUserByName**](UserApi.md#getUserByName) | **GET** /user/{username} | Get user by user name
+[**loginUser**](UserApi.md#loginUser) | **GET** /user/login | Logs user into the system
+[**logoutUser**](UserApi.md#logoutUser) | **GET** /user/logout | Logs out current logged in user session
+[**updateUser**](UserApi.md#updateUser) | **PUT** /user/{username} | Updated user
+
+
+
+## createUser
+
+> createUser(body)
+
+Create user
+
+This can only be done by the logged in user.
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        User body = new User(); // User | Created user object
+        try {
+            apiInstance.createUser(body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#createUser");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**User**](User.md)| Created user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **0** | successful operation |  -  |
+
+
+## createUsersWithArrayInput
+
+> createUsersWithArrayInput(body)
+
+Creates list of users with given input array
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        List<User> body = Arrays.asList(); // List<User> | List of user object
+        try {
+            apiInstance.createUsersWithArrayInput(body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#createUsersWithArrayInput");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**List&lt;User&gt;**](User.md)| List of user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **0** | successful operation |  -  |
+
+
+## createUsersWithListInput
+
+> createUsersWithListInput(body)
+
+Creates list of users with given input array
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        List<User> body = Arrays.asList(); // List<User> | List of user object
+        try {
+            apiInstance.createUsersWithListInput(body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#createUsersWithListInput");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **body** | [**List&lt;User&gt;**](User.md)| List of user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **0** | successful operation |  -  |
+
+
+## deleteUser
+
+> deleteUser(username)
+
+Delete user
+
+This can only be done by the logged in user.
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        String username = "username_example"; // String | The name that needs to be deleted
+        try {
+            apiInstance.deleteUser(username);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#deleteUser");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **String**| The name that needs to be deleted |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **400** | Invalid username supplied |  -  |
+| **404** | User not found |  -  |
+
+
+## getUserByName
+
+> User getUserByName(username)
+
+Get user by user name
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        String username = "username_example"; // String | The name that needs to be fetched. Use user1 for testing.
+        try {
+            User result = apiInstance.getUserByName(username);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#getUserByName");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **String**| The name that needs to be fetched. Use user1 for testing. |
+
+### Return type
+
+[**User**](User.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+| **400** | Invalid username supplied |  -  |
+| **404** | User not found |  -  |
+
+
+## loginUser
+
+> String loginUser(username, password)
+
+Logs user into the system
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        String username = "username_example"; // String | The user name for login
+        String password = "password_example"; // String | The password for login in clear text
+        try {
+            String result = apiInstance.loginUser(username, password);
+            System.out.println(result);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#loginUser");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **String**| The user name for login |
+ **password** | **String**| The password for login in clear text |
+
+### Return type
+
+**String**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: application/xml, application/json
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  * X-Rate-Limit - calls per hour allowed by the user <br>  * X-Expires-After - date in UTC when token expires <br>  |
+| **400** | Invalid username/password supplied |  -  |
+
+
+## logoutUser
+
+> logoutUser()
+
+Logs out current logged in user session
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        try {
+            apiInstance.logoutUser();
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#logoutUser");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+This endpoint does not need any parameter.
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **0** | successful operation |  -  |
+
+
+## updateUser
+
+> updateUser(username, body)
+
+Updated user
+
+This can only be done by the logged in user.
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.UserApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        UserApi apiInstance = new UserApi(defaultClient);
+        String username = "username_example"; // String | name that need to be deleted
+        User body = new User(); // User | Updated user object
+        try {
+            apiInstance.updateUser(username, body);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling UserApi#updateUser");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **username** | **String**| name that need to be deleted |
+ **body** | [**User**](User.md)| Updated user object |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **400** | Invalid user supplied |  -  |
+| **404** | User not found |  -  |
+

samples/client/petstore/java/apache-httpclient/docs/XmlItem.md

@@ -0,0 +1,41 @@
+
+
+# XmlItem
+
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**attributeString** | **String** |  |  [optional]
+**attributeNumber** | **BigDecimal** |  |  [optional]
+**attributeInteger** | **Integer** |  |  [optional]
+**attributeBoolean** | **Boolean** |  |  [optional]
+**wrappedArray** | **List<Integer>** |  |  [optional]
+**nameString** | **String** |  |  [optional]
+**nameNumber** | **BigDecimal** |  |  [optional]
+**nameInteger** | **Integer** |  |  [optional]
+**nameBoolean** | **Boolean** |  |  [optional]
+**nameArray** | **List<Integer>** |  |  [optional]
+**nameWrappedArray** | **List<Integer>** |  |  [optional]
+**prefixString** | **String** |  |  [optional]
+**prefixNumber** | **BigDecimal** |  |  [optional]
+**prefixInteger** | **Integer** |  |  [optional]
+**prefixBoolean** | **Boolean** |  |  [optional]
+**prefixArray** | **List<Integer>** |  |  [optional]
+**prefixWrappedArray** | **List<Integer>** |  |  [optional]
+**namespaceString** | **String** |  |  [optional]
+**namespaceNumber** | **BigDecimal** |  |  [optional]
+**namespaceInteger** | **Integer** |  |  [optional]
+**namespaceBoolean** | **Boolean** |  |  [optional]
+**namespaceArray** | **List<Integer>** |  |  [optional]
+**namespaceWrappedArray** | **List<Integer>** |  |  [optional]
+**prefixNsString** | **String** |  |  [optional]
+**prefixNsNumber** | **BigDecimal** |  |  [optional]
+**prefixNsInteger** | **Integer** |  |  [optional]
+**prefixNsBoolean** | **Boolean** |  |  [optional]
+**prefixNsArray** | **List<Integer>** |  |  [optional]
+**prefixNsWrappedArray** | **List<Integer>** |  |  [optional]
+
+
+

samples/client/petstore/java/apache-httpclient/git_push.sh

@@ -0,0 +1,57 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-pestore-perl "minor update" "gitlab.com"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+git_host=$4
+
+if [ "$git_host" = "" ]; then
+    git_host="github.com"
+    echo "[INFO] No command line input provided. Set \$git_host to $git_host"
+fi
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository.
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=`git remote`
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://${git_host}/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:${GIT_TOKEN}@${git_host}/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://${git_host}/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'

samples/client/petstore/java/apache-httpclient/gradle.properties

@@ -0,0 +1,2 @@
+# Uncomment to build for Android
+#target = android

samples/client/petstore/java/apache-httpclient/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

samples/client/petstore/java/apache-httpclient/gradlew

@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"

samples/client/petstore/java/apache-httpclient/gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

samples/client/petstore/java/apache-httpclient/pom.xml

@@ -0,0 +1,298 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>org.openapitools</groupId>
+    <artifactId>petstore-apache-httpclient</artifactId>
+    <packaging>jar</packaging>
+    <name>petstore-apache-httpclient</name>
+    <version>1.0.0</version>
+    <url>https://github.com/openapitools/openapi-generator</url>
+    <description>OpenAPI Java</description>
+    <scm>
+        <connection>scm:git:git@github.com:openapitools/openapi-generator.git</connection>
+        <developerConnection>scm:git:git@github.com:openapitools/openapi-generator.git</developerConnection>
+        <url>https://github.com/openapitools/openapi-generator</url>
+    </scm>
+
+    <licenses>
+        <license>
+            <name>Unlicense</name>
+            <url>https://www.apache.org/licenses/LICENSE-2.0.html</url>
+            <distribution>repo</distribution>
+        </license>
+    </licenses>
+
+    <developers>
+        <developer>
+            <name>OpenAPI-Generator Contributors</name>
+            <email>team@openapitools.org</email>
+            <organization>OpenAPITools.org</organization>
+            <organizationUrl>http://openapitools.org</organizationUrl>
+        </developer>
+    </developers>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <fork>true</fork>
+                    <meminitial>128m</meminitial>
+                    <maxmem>512m</maxmem>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                        <arg>-J-Xss4m</arg><!-- Compiling the generated JSON.java file may require larger stack size. -->
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+                <version>3.0.0-M1</version>
+                <executions>
+                    <execution>
+                        <id>enforce-maven</id>
+                        <goals>
+                            <goal>enforce</goal>
+                        </goals>
+                        <configuration>
+                            <rules>
+                                <requireMavenVersion>
+                                    <version>2.2.0</version>
+                                </requireMavenVersion>
+                            </rules>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.12</version>
+                <configuration>
+                    <systemProperties>
+                        <property>
+                            <name>loggerPath</name>
+                            <value>conf/log4j.properties</value>
+                        </property>
+                    </systemProperties>
+                    <argLine>-Xms512m -Xmx1500m</argLine>
+                    <parallel>methods</parallel>
+                    <forkMode>pertest</forkMode>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/lib</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <!-- attach test jar -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>2.2</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>jar</goal>
+                            <goal>test-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>build-helper-maven-plugin</artifactId>
+                <version>1.10</version>
+                <executions>
+                    <execution>
+                        <id>add_sources</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>add-source</goal>
+                        </goals>
+                        <configuration>
+                            <sources>
+                                <source>src/main/java</source>
+                            </sources>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>add_test_sources</id>
+                        <phase>generate-test-sources</phase>
+                        <goals>
+                            <goal>add-test-source</goal>
+                        </goals>
+                        <configuration>
+                            <sources>
+                                <source>src/test/java</source>
+                            </sources>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.6.1</version>
+                <configuration>
+                        <source>1.8</source>
+                        <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>3.1.1</version>
+                <configuration>
+                    <doclint>none</doclint>
+                        <source>1.8</source>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>attach-javadocs</id>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+                <version>2.2.1</version>
+                <executions>
+                    <execution>
+                        <id>attach-sources</id>
+                        <goals>
+                            <goal>jar-no-fork</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>sign-artifacts</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-gpg-plugin</artifactId>
+                        <version>1.5</version>
+                        <executions>
+                            <execution>
+                                <id>sign-artifacts</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>sign</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.swagger</groupId>
+            <artifactId>swagger-annotations</artifactId>
+            <version>${swagger-annotations-version}</version>
+        </dependency>
+
+        <!-- @Nullable annotation -->
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+            <version>3.0.2</version>
+        </dependency>
+
+
+        <!-- HTTP client: jersey-client -->
+        <dependency>
+            <groupId>com.sun.jersey</groupId>
+            <artifactId>jersey-client</artifactId>
+            <version>${jersey-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.sun.jersey.contribs</groupId>
+            <artifactId>jersey-multipart</artifactId>
+            <version>${jersey-version}</version>
+        </dependency>
+
+        <!-- JSON processing: jackson -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-core</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.jaxrs</groupId>
+            <artifactId>jackson-jaxrs-json-provider</artifactId>
+            <version>${jackson-version}</version>
+        </dependency>
+            <dependency>
+                <groupId>com.fasterxml.jackson.datatype</groupId>
+                <artifactId>jackson-datatype-jsr310</artifactId>
+                <version>${jackson-version}</version>
+            </dependency>
+            <dependency>
+                <groupId>com.github.joschi.jackson</groupId>
+                <artifactId>jackson-datatype-threetenbp</artifactId>
+                <version>${jackson-threetenbp-version}</version>
+            </dependency>
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <version>${javax-annotation-version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- test dependencies -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit-version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <swagger-annotations-version>1.5.21</swagger-annotations-version>
+        <jersey-version>1.19.4</jersey-version>
+        <jackson-version>2.12.1</jackson-version>
+        <jackson-threetenbp-version>2.9.10</jackson-threetenbp-version>
+        <javax-annotation-version>1.3.2</javax-annotation-version>
+        <maven-plugin-version>1.0.0</maven-plugin-version>
+        <junit-version>4.13.1</junit-version>
+    </properties>
+</project>

samples/client/petstore/java/apache-httpclient/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "petstore-apache-httpclient"

samples/client/petstore/java/apache-httpclient/src/main/AndroidManifest.xml

@@ -0,0 +1,3 @@
+<manifest package="org.openapitools.client" xmlns:android="http://schemas.android.com/apk/res/android">
+    <application />
+</manifest>

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/ApiClient.java

@@ -0,0 +1,848 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client;
+
+import org.threeten.bp.*;
+
+import com.fasterxml.jackson.annotation.*;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.fasterxml.jackson.datatype.threetenbp.ThreeTenModule;
+import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
+
+import com.sun.jersey.api.client.Client;
+import com.sun.jersey.api.client.ClientResponse;
+import com.sun.jersey.api.client.GenericType;
+import com.sun.jersey.api.client.config.DefaultClientConfig;
+import com.sun.jersey.api.client.filter.GZIPContentEncodingFilter;
+import com.sun.jersey.api.client.filter.LoggingFilter;
+import com.sun.jersey.api.client.WebResource.Builder;
+
+import com.sun.jersey.multipart.FormDataMultiPart;
+import com.sun.jersey.multipart.file.FileDataBodyPart;
+
+import javax.ws.rs.core.Cookie;
+import javax.ws.rs.core.Response.Status.Family;
+import javax.ws.rs.core.MediaType;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.TimeZone;
+
+import java.net.URLEncoder;
+
+import java.io.File;
+import java.io.UnsupportedEncodingException;
+
+import java.text.DateFormat;
+
+import org.openapitools.client.auth.Authentication;
+import org.openapitools.client.auth.HttpBasicAuth;
+import org.openapitools.client.auth.ApiKeyAuth;
+import org.openapitools.client.auth.OAuth;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ApiClient extends JavaTimeFormatter {
+  private Map<String, String> defaultHeaderMap = new HashMap<String, String>();
+  private Map<String, String> defaultCookieMap = new HashMap<String, String>();
+  private String basePath = "http://petstore.swagger.io:80/v2";
+  protected List<ServerConfiguration> servers = new ArrayList<ServerConfiguration>(Arrays.asList(
+    new ServerConfiguration(
+      "http://petstore.swagger.io:80/v2",
+      "No description provided",
+      new HashMap<String, ServerVariable>()
+    )
+  ));
+  protected Integer serverIndex = 0;
+  protected Map<String, String> serverVariables = null;
+  private boolean debugging = false;
+  private int connectionTimeout = 0;
+
+  private Client httpClient;
+  private ObjectMapper objectMapper;
+
+  private Map<String, Authentication> authentications;
+
+  private int statusCode;
+  private Map<String, List<String>> responseHeaders;
+
+  private DateFormat dateFormat;
+
+  public ApiClient() {
+    objectMapper = new ObjectMapper();
+    objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
+    objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    objectMapper.configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false);
+    objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+    objectMapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
+    objectMapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
+    objectMapper.registerModule(new JavaTimeModule());
+    ThreeTenModule module = new ThreeTenModule();
+    module.addDeserializer(Instant.class, CustomInstantDeserializer.INSTANT);
+    module.addDeserializer(OffsetDateTime.class, CustomInstantDeserializer.OFFSET_DATE_TIME);
+    module.addDeserializer(ZonedDateTime.class, CustomInstantDeserializer.ZONED_DATE_TIME);
+    objectMapper.registerModule(module);
+    objectMapper.setDateFormat(ApiClient.buildDefaultDateFormat());
+
+    dateFormat = ApiClient.buildDefaultDateFormat();
+
+    // Set default User-Agent.
+    setUserAgent("OpenAPI-Generator/1.0.0/java");
+
+    // Setup authentications (key: authentication name, value: authentication).
+    authentications = new HashMap<String, Authentication>();
+    authentications.put("api_key", new ApiKeyAuth("header", "api_key"));
+    authentications.put("api_key_query", new ApiKeyAuth("query", "api_key_query"));
+    authentications.put("http_basic_test", new HttpBasicAuth());
+    authentications.put("petstore_auth", new OAuth());
+    // Prevent the authentications from being modified.
+    authentications = Collections.unmodifiableMap(authentications);
+
+    rebuildHttpClient();
+  }
+
+  public static DateFormat buildDefaultDateFormat() {
+    return new RFC3339DateFormat();
+  }
+
+  /**
+   * Build the Client used to make HTTP requests with the latest settings,
+   * i.e. objectMapper and debugging.
+   * TODO: better to use the Builder Pattern?
+   * @return API client
+   */
+  public ApiClient rebuildHttpClient() {
+    // Add the JSON serialization support to Jersey
+    JacksonJsonProvider jsonProvider = new JacksonJsonProvider(objectMapper);
+    DefaultClientConfig conf = new DefaultClientConfig();
+    conf.getSingletons().add(jsonProvider);
+    Client client = Client.create(conf);
+    client.addFilter(new GZIPContentEncodingFilter(false));
+    if (debugging) {
+      client.addFilter(new LoggingFilter());
+    }
+    this.httpClient = client;
+    return this;
+  }
+
+  /**
+   * Returns the current object mapper used for JSON serialization/deserialization.
+   * <p>
+   * Note: If you make changes to the object mapper, remember to set it back via
+   * <code>setObjectMapper</code> in order to trigger HTTP client rebuilding.
+   * </p>
+   * @return Object mapper
+   */
+  public ObjectMapper getObjectMapper() {
+    return objectMapper;
+  }
+
+  public ApiClient setObjectMapper(ObjectMapper objectMapper) {
+    this.objectMapper = objectMapper;
+    // Need to rebuild the Client as it depends on object mapper.
+    rebuildHttpClient();
+    return this;
+  }
+
+  public Client getHttpClient() {
+    return httpClient;
+  }
+
+  public ApiClient setHttpClient(Client httpClient) {
+    this.httpClient = httpClient;
+    return this;
+  }
+
+  public String getBasePath() {
+    return basePath;
+  }
+
+  public ApiClient setBasePath(String basePath) {
+    this.basePath = basePath;
+    return this;
+  }
+
+  public List<ServerConfiguration> getServers() {
+    return servers;
+  }
+
+  public ApiClient setServers(List<ServerConfiguration> servers) {
+    this.servers = servers;
+    return this;
+  }
+
+  public Integer getServerIndex() {
+    return serverIndex;
+  }
+
+  public ApiClient setServerIndex(Integer serverIndex) {
+    this.serverIndex = serverIndex;
+    return this;
+  }
+
+  public Map<String, String> getServerVariables() {
+    return serverVariables;
+  }
+
+  public ApiClient setServerVariables(Map<String, String> serverVariables) {
+    this.serverVariables = serverVariables;
+    return this;
+  }
+
+  /**
+   * Gets the status code of the previous request
+   * @return Status code
+   */
+  public int getStatusCode() {
+    return statusCode;
+  }
+
+  /**
+   * Gets the response headers of the previous request
+   * @return Response headers
+   */
+  public Map<String, List<String>> getResponseHeaders() {
+    return responseHeaders;
+  }
+
+  /**
+   * Get authentications (key: authentication name, value: authentication).
+   * @return Map of authentication
+   */
+  public Map<String, Authentication> getAuthentications() {
+    return authentications;
+  }
+
+  /**
+   * Get authentication for the given name.
+   *
+   * @param authName The authentication name
+   * @return The authentication, null if not found
+   */
+  public Authentication getAuthentication(String authName) {
+    return authentications.get(authName);
+  }
+
+
+  /**
+   * Helper method to set username for the first HTTP basic authentication.
+   * @param username Username
+   */
+  public void setUsername(String username) {
+    for (Authentication auth : authentications.values()) {
+      if (auth instanceof HttpBasicAuth) {
+        ((HttpBasicAuth) auth).setUsername(username);
+        return;
+      }
+    }
+    throw new RuntimeException("No HTTP basic authentication configured!");
+  }
+
+  /**
+   * Helper method to set password for the first HTTP basic authentication.
+   * @param password Password
+   */
+  public void setPassword(String password) {
+    for (Authentication auth : authentications.values()) {
+      if (auth instanceof HttpBasicAuth) {
+        ((HttpBasicAuth) auth).setPassword(password);
+        return;
+      }
+    }
+    throw new RuntimeException("No HTTP basic authentication configured!");
+  }
+
+
+  /**
+   * Helper method to set API key value for the first API key authentication.
+   * @param apiKey the API key
+   */
+  public void setApiKey(String apiKey) {
+    for (Authentication auth : authentications.values()) {
+      if (auth instanceof ApiKeyAuth) {
+        ((ApiKeyAuth) auth).setApiKey(apiKey);
+        return;
+      }
+    }
+    throw new RuntimeException("No API key authentication configured!");
+  }
+
+  /**
+   * Helper method to set API key prefix for the first API key authentication.
+   * @param apiKeyPrefix API key prefix
+   */
+  public void setApiKeyPrefix(String apiKeyPrefix) {
+    for (Authentication auth : authentications.values()) {
+      if (auth instanceof ApiKeyAuth) {
+        ((ApiKeyAuth) auth).setApiKeyPrefix(apiKeyPrefix);
+        return;
+      }
+    }
+    throw new RuntimeException("No API key authentication configured!");
+  }
+
+
+  /**
+   * Helper method to set access token for the first OAuth2 authentication.
+   * @param accessToken Access token
+   */
+  public void setAccessToken(String accessToken) {
+    for (Authentication auth : authentications.values()) {
+      if (auth instanceof OAuth) {
+        ((OAuth) auth).setAccessToken(accessToken);
+        return;
+      }
+    }
+    throw new RuntimeException("No OAuth2 authentication configured!");
+  }
+
+
+  /**
+   * Set the User-Agent header's value (by adding to the default header map).
+   * @param userAgent User agent
+   * @return API client
+   */
+  public ApiClient setUserAgent(String userAgent) {
+    addDefaultHeader("User-Agent", userAgent);
+    return this;
+  }
+
+  /**
+   * Add a default header.
+   *
+   * @param key The header's key
+   * @param value The header's value
+   * @return API client
+   */
+  public ApiClient addDefaultHeader(String key, String value) {
+    defaultHeaderMap.put(key, value);
+    return this;
+  }
+
+  /**
+   * Add a default cookie.
+   *
+   * @param key The cookie's key
+   * @param value The cookie's value
+   * @return API client
+   */
+  public ApiClient addDefaultCookie(String key, String value) {
+    defaultCookieMap.put(key, value);
+    return this;
+  }
+
+  /**
+   * Check that whether debugging is enabled for this API client.
+   * @return True if debugging is on
+   */
+  public boolean isDebugging() {
+    return debugging;
+  }
+
+  /**
+   * Enable/disable debugging for this API client.
+   *
+   * @param debugging To enable (true) or disable (false) debugging
+   * @return API client
+   */
+  public ApiClient setDebugging(boolean debugging) {
+    this.debugging = debugging;
+    // Need to rebuild the Client as it depends on the value of debugging.
+    rebuildHttpClient();
+    return this;
+  }
+
+  /**
+   * Connect timeout (in milliseconds).
+   * @return Connection timeout
+   */
+  public int getConnectTimeout() {
+    return connectionTimeout;
+  }
+
+  /**
+   * Set the connect timeout (in milliseconds).
+   * A value of 0 means no timeout, otherwise values must be between 1 and
+   * {@link Integer#MAX_VALUE}.
+   * @param connectionTimeout Connection timeout in milliseconds
+   * @return API client
+   */
+   public ApiClient setConnectTimeout(int connectionTimeout) {
+     this.connectionTimeout = connectionTimeout;
+     httpClient.setConnectTimeout(connectionTimeout);
+     return this;
+   }
+
+  /**
+   * Get the date format used to parse/format date parameters.
+   * @return Date format
+   */
+  public DateFormat getDateFormat() {
+    return dateFormat;
+  }
+
+  /**
+   * Set the date format used to parse/format date parameters.
+   * @param dateFormat Date format
+   * @return API client
+   */
+  public ApiClient setDateFormat(DateFormat dateFormat) {
+    this.dateFormat = dateFormat;
+    // Also set the date format for model (de)serialization with Date properties.
+    this.objectMapper.setDateFormat((DateFormat) dateFormat.clone());
+    // Need to rebuild the Client as objectMapper changes.
+    rebuildHttpClient();
+    return this;
+  }
+
+  /**
+   * Parse the given string into Date object.
+   * @param str String
+   * @return Date
+   */
+  public Date parseDate(String str) {
+    try {
+      return dateFormat.parse(str);
+    } catch (java.text.ParseException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  /**
+   * Format the given Date object into string.
+   * @param date Date
+   * @return Date in string format
+   */
+  public String formatDate(Date date) {
+    return dateFormat.format(date);
+  }
+
+  /**
+   * Format the given parameter object into string.
+   * @param param Object
+   * @return Object in string format
+   */
+  public String parameterToString(Object param) {
+    if (param == null) {
+      return "";
+    } else if (param instanceof Date) {
+      return formatDate((Date) param);
+    } else if (param instanceof OffsetDateTime) {
+      return formatOffsetDateTime((OffsetDateTime) param);
+    } else if (param instanceof Collection) {
+      StringBuilder b = new StringBuilder();
+      for(Object o : (Collection<?>)param) {
+        if(b.length() > 0) {
+          b.append(',');
+        }
+        b.append(String.valueOf(o));
+      }
+      return b.toString();
+    } else {
+      return String.valueOf(param);
+    }
+  }
+
+  /**
+   * Formats the specified query parameter to a list containing a single {@code Pair} object.
+   *
+   * Note that {@code value} must not be a collection.
+   *
+   * @param name The name of the parameter.
+   * @param value The value of the parameter.
+   * @return A list containing a single {@code Pair} object.
+   */
+  public List<Pair> parameterToPair(String name, Object value) {
+    List<Pair> params = new ArrayList<Pair>();
+
+    // preconditions
+    if (name == null || name.isEmpty() || value == null || value instanceof Collection) return params;
+
+    params.add(new Pair(name, parameterToString(value)));
+    return params;
+  }
+
+  /**
+   * Formats the specified collection query parameters to a list of {@code Pair} objects.
+   *
+   * Note that the values of each of the returned Pair objects are percent-encoded.
+   *
+   * @param collectionFormat The collection format of the parameter.
+   * @param name The name of the parameter.
+   * @param value The value of the parameter.
+   * @return A list of {@code Pair} objects.
+   */
+  public List<Pair> parameterToPairs(String collectionFormat, String name, Collection value) {
+    List<Pair> params = new ArrayList<Pair>();
+
+    // preconditions
+    if (name == null || name.isEmpty() || value == null) {
+      return params;
+    }
+
+    // create the params based on the collection format
+    if ("multi".equals(collectionFormat)) {
+      for (Object item : value) {
+        params.add(new Pair(name, escapeString(parameterToString(item))));
+      }
+      return params;
+    }
+
+    // collectionFormat is assumed to be "csv" by default
+    String delimiter = ",";
+
+    // escape all delimiters except commas, which are URI reserved
+    // characters
+    if ("ssv".equals(collectionFormat)) {
+      delimiter = escapeString(" ");
+    } else if ("tsv".equals(collectionFormat)) {
+      delimiter = escapeString("\t");
+    } else if ("pipes".equals(collectionFormat)) {
+      delimiter = escapeString("|");
+    }
+
+    StringBuilder sb = new StringBuilder() ;
+    for (Object item : value) {
+      sb.append(delimiter);
+      sb.append(escapeString(parameterToString(item)));
+    }
+
+    params.add(new Pair(name, sb.substring(delimiter.length())));
+
+    return params;
+  }
+
+  /**
+   * Check if the given MIME is a JSON MIME.
+   * JSON MIME examples:
+   *   application/json
+   *   application/json; charset=UTF8
+   *   APPLICATION/JSON
+   *   application/vnd.company+json
+   * @param mime MIME
+   * @return True if MIME type is boolean
+   */
+  public boolean isJsonMime(String mime) {
+    String jsonMime = "(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$";
+    return mime != null && (mime.matches(jsonMime) || mime.equals("*/*"));
+  }
+
+  /**
+   * Select the Accept header's value from the given accepts array:
+   *   if JSON exists in the given array, use it;
+   *   otherwise use all of them (joining into a string)
+   *
+   * @param accepts The accepts array to select from
+   * @return The Accept header to use. If the given array is empty,
+   *   null will be returned (not to set the Accept header explicitly).
+   */
+  public String selectHeaderAccept(String[] accepts) {
+    if (accepts.length == 0) {
+      return null;
+    }
+    for (String accept : accepts) {
+      if (isJsonMime(accept)) {
+        return accept;
+      }
+    }
+    return StringUtil.join(accepts, ",");
+  }
+
+  /**
+   * Select the Content-Type header's value from the given array:
+   *   if JSON exists in the given array, use it;
+   *   otherwise use the first one of the array.
+   *
+   * @param contentTypes The Content-Type array to select from
+   * @return The Content-Type header to use. If the given array is empty,
+   *   or matches "any", JSON will be used.
+   */
+  public String selectHeaderContentType(String[] contentTypes) {
+    if (contentTypes.length == 0 || contentTypes[0].equals("*/*")) {
+      return "application/json";
+    }
+    for (String contentType : contentTypes) {
+      if (isJsonMime(contentType)) {
+        return contentType;
+      }
+    }
+    return contentTypes[0];
+  }
+
+  /**
+   * Escape the given string to be used as URL query value.
+   * @param str String
+   * @return Escaped string
+   */
+  public String escapeString(String str) {
+    try {
+      return URLEncoder.encode(str, "utf8").replaceAll("\\+", "%20");
+    } catch (UnsupportedEncodingException e) {
+      return str;
+    }
+  }
+
+  /**
+   * Serialize the given Java object into string according the given
+   * Content-Type (only JSON is supported for now).
+   * @param obj Object
+   * @param contentType Content type
+   * @param formParams Form parameters
+   * @return Object
+   * @throws ApiException API exception
+   */
+  public Object serialize(Object obj, String contentType, Map<String, Object> formParams) throws ApiException {
+    if (contentType.startsWith("multipart/form-data")) {
+      FormDataMultiPart mp = new FormDataMultiPart();
+      for (Entry<String, Object> param: formParams.entrySet()) {
+        if( param.getValue() instanceof List && !( ( List ) param.getValue() ).isEmpty()
+                  && ( ( List ) param.getValue() ).get( 0 ) instanceof File ) {
+            @SuppressWarnings( "unchecked" )
+            List<File> files = ( List<File> ) param.getValue();
+            for( File file : files ) {
+              mp.bodyPart( new FileDataBodyPart( param.getKey(), file, MediaType.APPLICATION_OCTET_STREAM_TYPE ) );
+            }
+        } else if (param.getValue() instanceof File) {
+          File file = (File) param.getValue();
+          mp.bodyPart(new FileDataBodyPart(param.getKey(), file, MediaType.APPLICATION_OCTET_STREAM_TYPE));
+        } else {
+          mp.field(param.getKey(), parameterToString(param.getValue()), MediaType.MULTIPART_FORM_DATA_TYPE);
+        }
+      }
+      return mp;
+    } else if (contentType.startsWith("application/x-www-form-urlencoded")) {
+      return this.getXWWWFormUrlencodedParams(formParams);
+    } else {
+      // We let Jersey attempt to serialize the body
+      return obj;
+    }
+  }
+
+  /**
+   * Build full URL by concatenating base path, the given sub path and query parameters.
+   *
+   * @param path The sub path
+   * @param queryParams The query parameters
+   * @param collectionQueryParams The collection query parameters
+   * @return The full URL
+   */
+  private String buildUrl(String path, List<Pair> queryParams, List<Pair> collectionQueryParams) {
+    String baseURL;
+    if (serverIndex != null) {
+      if (serverIndex < 0 || serverIndex >= servers.size()) {
+        throw new ArrayIndexOutOfBoundsException(String.format(
+          "Invalid index %d when selecting the host settings. Must be less than %d", serverIndex, servers.size()
+        ));
+      }
+      baseURL = servers.get(serverIndex).URL(serverVariables);
+    } else {
+      baseURL = basePath;
+    }
+
+    final StringBuilder url = new StringBuilder();
+    url.append(baseURL).append(path);
+
+    if (queryParams != null && !queryParams.isEmpty()) {
+      // support (constant) query string in `path`, e.g. "/posts?draft=1"
+      String prefix = path.contains("?") ? "&" : "?";
+      for (Pair param : queryParams) {
+        if (param.getValue() != null) {
+          if (prefix != null) {
+            url.append(prefix);
+            prefix = null;
+          } else {
+            url.append("&");
+          }
+          String value = parameterToString(param.getValue());
+          url.append(escapeString(param.getName())).append("=").append(escapeString(value));
+        }
+      }
+    }
+
+    if (collectionQueryParams != null && !collectionQueryParams.isEmpty()) {
+      String prefix = url.toString().contains("?") ? "&" : "?";
+      for (Pair param : collectionQueryParams) {
+        if (param.getValue() != null) {
+          if (prefix != null) {
+            url.append(prefix);
+            prefix = null;
+          } else {
+            url.append("&");
+          }
+          String value = parameterToString(param.getValue());
+          // collection query parameter value already escaped as part of parameterToPairs
+          url.append(escapeString(param.getName())).append("=").append(value);
+        }
+      }
+    }
+
+    return url.toString();
+  }
+
+  private ClientResponse getAPIResponse(String path, String method, List<Pair> queryParams, List<Pair> collectionQueryParams, Object body, Map<String, String> headerParams, Map<String, String> cookieParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames) throws ApiException {
+    if (body != null && !formParams.isEmpty()) {
+      throw new ApiException(500, "Cannot have body and form params");
+    }
+
+    updateParamsForAuth(authNames, queryParams, headerParams, cookieParams);
+
+    final String url = buildUrl(path, queryParams, collectionQueryParams);
+    Builder builder;
+    if (accept == null) {
+      builder = httpClient.resource(url).getRequestBuilder();
+    } else {
+      builder = httpClient.resource(url).accept(accept);
+    }
+
+    for (Entry<String, String> keyValue : headerParams.entrySet()) {
+      builder = builder.header(keyValue.getKey(), keyValue.getValue());
+    }
+    for (Map.Entry<String,String> keyValue : defaultHeaderMap.entrySet()) {
+      if (!headerParams.containsKey(keyValue.getKey())) {
+        builder = builder.header(keyValue.getKey(), keyValue.getValue());
+      }
+    }
+
+    for (Entry<String, String> keyValue : cookieParams.entrySet()) {
+      builder = builder.cookie(new Cookie(keyValue.getKey(), keyValue.getValue()));
+    }
+    for (Map.Entry<String,String> keyValue : defaultCookieMap.entrySet()) {
+      if (!cookieParams.containsKey(keyValue.getKey())) {
+        builder = builder.cookie(new Cookie(keyValue.getKey(), keyValue.getValue()));
+      }
+    }
+
+    ClientResponse response = null;
+
+    if ("GET".equals(method)) {
+      response = (ClientResponse) builder.get(ClientResponse.class);
+    } else if ("POST".equals(method)) {
+      response = builder.type(contentType).post(ClientResponse.class, serialize(body, contentType, formParams));
+    } else if ("PUT".equals(method)) {
+      response = builder.type(contentType).put(ClientResponse.class, serialize(body, contentType, formParams));
+    } else if ("DELETE".equals(method)) {
+      response = builder.type(contentType).delete(ClientResponse.class, serialize(body, contentType, formParams));
+    } else if ("PATCH".equals(method)) {
+      response = builder.type(contentType).header("X-HTTP-Method-Override", "PATCH").post(ClientResponse.class, serialize(body, contentType, formParams));
+    } else if ("HEAD".equals(method)) {
+      response = builder.head();
+    } else {
+      throw new ApiException(500, "unknown method type " + method);
+    }
+    return response;
+  }
+
+  /**
+   * Invoke API by sending HTTP request with the given options.
+   *
+   * @param <T> Type
+   * @param path The sub-path of the HTTP URL
+   * @param method The request method, one of "GET", "POST", "PUT", and "DELETE"
+   * @param queryParams The query parameters
+   * @param collectionQueryParams The collection query parameters
+   * @param body The request body object - if it is not binary, otherwise null
+   * @param headerParams The header parameters
+   * @param cookieParams The cookie parameters
+   * @param formParams The form parameters
+   * @param accept The request's Accept header
+   * @param contentType The request's Content-Type header
+   * @param authNames The authentications to apply
+   * @param returnType Return type
+   * @return The response body in type of string
+   * @throws ApiException API exception
+   */
+   public <T> T invokeAPI(String path, String method, List<Pair> queryParams, List<Pair> collectionQueryParams, Object body, Map<String, String> headerParams, Map<String, String> cookieParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames, GenericType<T> returnType) throws ApiException {
+
+    ClientResponse response = getAPIResponse(path, method, queryParams, collectionQueryParams, body, headerParams, cookieParams, formParams, accept, contentType, authNames);
+
+    statusCode = response.getStatusInfo().getStatusCode();
+    responseHeaders = response.getHeaders();
+
+    if(response.getStatusInfo().getStatusCode() == ClientResponse.Status.NO_CONTENT.getStatusCode()) {
+      return null;
+    } else if (response.getStatusInfo().getFamily() == Family.SUCCESSFUL) {
+      if (returnType == null)
+        return null;
+      else
+        return response.getEntity(returnType);
+    } else {
+      String message = "error";
+      String respBody = null;
+      if (response.hasEntity()) {
+        try {
+          respBody = response.getEntity(String.class);
+          message = respBody;
+        } catch (RuntimeException e) {
+          // e.printStackTrace();
+        }
+      }
+      throw new ApiException(
+        response.getStatusInfo().getStatusCode(),
+        message,
+        response.getHeaders(),
+        respBody);
+    }
+  }
+
+  /**
+   * Update query and header parameters based on authentication settings.
+   *
+   * @param authNames The authentications to apply
+   * @param queryParams Query parameters
+   * @param headerParams Header parameters
+   * @param cookieParams Cookie parameters
+   */
+  private void updateParamsForAuth(String[] authNames, List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams) {
+    for (String authName : authNames) {
+      Authentication auth = authentications.get(authName);
+      if (auth == null) throw new RuntimeException("Authentication undefined: " + authName);
+      auth.applyToParams(queryParams, headerParams, cookieParams);
+    }
+  }
+
+  /**
+   * Encode the given form parameters as request body.
+   * @param formParams Form parameters
+   * @return HTTP form encoded parameters
+   */
+  private String getXWWWFormUrlencodedParams(Map<String, Object> formParams) {
+    StringBuilder formParamBuilder = new StringBuilder();
+
+    for (Entry<String, Object> param : formParams.entrySet()) {
+      String valueStr = parameterToString(param.getValue());
+      try {
+        formParamBuilder.append(URLEncoder.encode(param.getKey(), "utf8"))
+            .append("=")
+            .append(URLEncoder.encode(valueStr, "utf8"));
+        formParamBuilder.append("&");
+      } catch (UnsupportedEncodingException e) {
+        // move on to next
+      }
+    }
+
+    String encodedFormParams = formParamBuilder.toString();
+    if (encodedFormParams.endsWith("&")) {
+      encodedFormParams = encodedFormParams.substring(0, encodedFormParams.length() - 1);
+    }
+
+    return encodedFormParams;
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/ApiException.java

@@ -0,0 +1,91 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client;
+
+import java.util.Map;
+import java.util.List;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ApiException extends Exception {
+    private int code = 0;
+    private Map<String, List<String>> responseHeaders = null;
+    private String responseBody = null;
+
+    public ApiException() {}
+
+    public ApiException(Throwable throwable) {
+        super(throwable);
+    }
+
+    public ApiException(String message) {
+        super(message);
+    }
+
+    public ApiException(String message, Throwable throwable, int code, Map<String, List<String>> responseHeaders, String responseBody) {
+        super(message, throwable);
+        this.code = code;
+        this.responseHeaders = responseHeaders;
+        this.responseBody = responseBody;
+    }
+
+    public ApiException(String message, int code, Map<String, List<String>> responseHeaders, String responseBody) {
+        this(message, (Throwable) null, code, responseHeaders, responseBody);
+    }
+
+    public ApiException(String message, Throwable throwable, int code, Map<String, List<String>> responseHeaders) {
+        this(message, throwable, code, responseHeaders, null);
+    }
+
+    public ApiException(int code, Map<String, List<String>> responseHeaders, String responseBody) {
+        this((String) null, (Throwable) null, code, responseHeaders, responseBody);
+    }
+
+    public ApiException(int code, String message) {
+        super(message);
+        this.code = code;
+    }
+
+    public ApiException(int code, String message, Map<String, List<String>> responseHeaders, String responseBody) {
+        this(code, message);
+        this.responseHeaders = responseHeaders;
+        this.responseBody = responseBody;
+    }
+
+    /**
+     * Get the HTTP status code.
+     *
+     * @return HTTP status code
+     */
+    public int getCode() {
+        return code;
+    }
+
+    /**
+     * Get the HTTP response headers.
+     *
+     * @return A map of list of string
+     */
+    public Map<String, List<String>> getResponseHeaders() {
+        return responseHeaders;
+    }
+
+    /**
+     * Get the HTTP response body.
+     *
+     * @return Response body in the form of string
+     */
+    public String getResponseBody() {
+        return responseBody;
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/Configuration.java

@@ -0,0 +1,39 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Configuration {
+    private static ApiClient defaultApiClient = new ApiClient();
+
+    /**
+     * Get the default API client, which would be used when creating API
+     * instances without providing an API client.
+     *
+     * @return Default API client
+     */
+    public static ApiClient getDefaultApiClient() {
+        return defaultApiClient;
+    }
+
+    /**
+     * Set the default API client, which would be used when creating API
+     * instances without providing an API client.
+     *
+     * @param apiClient API client
+     */
+    public static void setDefaultApiClient(ApiClient apiClient) {
+        defaultApiClient = apiClient;
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/CustomInstantDeserializer.java

@@ -0,0 +1,232 @@
+package org.openapitools.client;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonTokenId;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.datatype.threetenbp.DecimalUtils;
+import com.fasterxml.jackson.datatype.threetenbp.deser.ThreeTenDateTimeDeserializerBase;
+import com.fasterxml.jackson.datatype.threetenbp.function.BiFunction;
+import com.fasterxml.jackson.datatype.threetenbp.function.Function;
+import org.threeten.bp.DateTimeException;
+import org.threeten.bp.DateTimeUtils;
+import org.threeten.bp.Instant;
+import org.threeten.bp.OffsetDateTime;
+import org.threeten.bp.ZoneId;
+import org.threeten.bp.ZonedDateTime;
+import org.threeten.bp.format.DateTimeFormatter;
+import org.threeten.bp.temporal.Temporal;
+import org.threeten.bp.temporal.TemporalAccessor;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+
+/**
+ * Deserializer for ThreeTen temporal {@link Instant}s, {@link OffsetDateTime}, and {@link ZonedDateTime}s.
+ * Adapted from the jackson threetenbp InstantDeserializer to add support for deserializing rfc822 format.
+ *
+ * @author Nick Williams
+ */
+public class CustomInstantDeserializer<T extends Temporal>
+    extends ThreeTenDateTimeDeserializerBase<T> {
+  private static final long serialVersionUID = 1L;
+
+  public static final CustomInstantDeserializer<Instant> INSTANT = new CustomInstantDeserializer<Instant>(
+      Instant.class, DateTimeFormatter.ISO_INSTANT,
+      new Function<TemporalAccessor, Instant>() {
+        @Override
+        public Instant apply(TemporalAccessor temporalAccessor) {
+          return Instant.from(temporalAccessor);
+        }
+      },
+      new Function<FromIntegerArguments, Instant>() {
+        @Override
+        public Instant apply(FromIntegerArguments a) {
+          return Instant.ofEpochMilli(a.value);
+        }
+      },
+      new Function<FromDecimalArguments, Instant>() {
+        @Override
+        public Instant apply(FromDecimalArguments a) {
+          return Instant.ofEpochSecond(a.integer, a.fraction);
+        }
+      },
+      null
+  );
+
+  public static final CustomInstantDeserializer<OffsetDateTime> OFFSET_DATE_TIME = new CustomInstantDeserializer<OffsetDateTime>(
+      OffsetDateTime.class, DateTimeFormatter.ISO_OFFSET_DATE_TIME,
+      new Function<TemporalAccessor, OffsetDateTime>() {
+        @Override
+        public OffsetDateTime apply(TemporalAccessor temporalAccessor) {
+          return OffsetDateTime.from(temporalAccessor);
+        }
+      },
+      new Function<FromIntegerArguments, OffsetDateTime>() {
+        @Override
+        public OffsetDateTime apply(FromIntegerArguments a) {
+          return OffsetDateTime.ofInstant(Instant.ofEpochMilli(a.value), a.zoneId);
+        }
+      },
+      new Function<FromDecimalArguments, OffsetDateTime>() {
+        @Override
+        public OffsetDateTime apply(FromDecimalArguments a) {
+          return OffsetDateTime.ofInstant(Instant.ofEpochSecond(a.integer, a.fraction), a.zoneId);
+        }
+      },
+      new BiFunction<OffsetDateTime, ZoneId, OffsetDateTime>() {
+        @Override
+        public OffsetDateTime apply(OffsetDateTime d, ZoneId z) {
+          return d.withOffsetSameInstant(z.getRules().getOffset(d.toLocalDateTime()));
+        }
+      }
+  );
+
+  public static final CustomInstantDeserializer<ZonedDateTime> ZONED_DATE_TIME = new CustomInstantDeserializer<ZonedDateTime>(
+      ZonedDateTime.class, DateTimeFormatter.ISO_ZONED_DATE_TIME,
+      new Function<TemporalAccessor, ZonedDateTime>() {
+        @Override
+        public ZonedDateTime apply(TemporalAccessor temporalAccessor) {
+          return ZonedDateTime.from(temporalAccessor);
+        }
+      },
+      new Function<FromIntegerArguments, ZonedDateTime>() {
+        @Override
+        public ZonedDateTime apply(FromIntegerArguments a) {
+          return ZonedDateTime.ofInstant(Instant.ofEpochMilli(a.value), a.zoneId);
+        }
+      },
+      new Function<FromDecimalArguments, ZonedDateTime>() {
+        @Override
+        public ZonedDateTime apply(FromDecimalArguments a) {
+          return ZonedDateTime.ofInstant(Instant.ofEpochSecond(a.integer, a.fraction), a.zoneId);
+        }
+      },
+      new BiFunction<ZonedDateTime, ZoneId, ZonedDateTime>() {
+        @Override
+        public ZonedDateTime apply(ZonedDateTime zonedDateTime, ZoneId zoneId) {
+          return zonedDateTime.withZoneSameInstant(zoneId);
+        }
+      }
+  );
+
+  protected final Function<FromIntegerArguments, T> fromMilliseconds;
+
+  protected final Function<FromDecimalArguments, T> fromNanoseconds;
+
+  protected final Function<TemporalAccessor, T> parsedToValue;
+
+  protected final BiFunction<T, ZoneId, T> adjust;
+
+  protected CustomInstantDeserializer(Class<T> supportedType,
+                    DateTimeFormatter parser,
+                    Function<TemporalAccessor, T> parsedToValue,
+                    Function<FromIntegerArguments, T> fromMilliseconds,
+                    Function<FromDecimalArguments, T> fromNanoseconds,
+                    BiFunction<T, ZoneId, T> adjust) {
+    super(supportedType, parser);
+    this.parsedToValue = parsedToValue;
+    this.fromMilliseconds = fromMilliseconds;
+    this.fromNanoseconds = fromNanoseconds;
+    this.adjust = adjust == null ? new BiFunction<T, ZoneId, T>() {
+      @Override
+      public T apply(T t, ZoneId zoneId) {
+        return t;
+      }
+    } : adjust;
+  }
+
+  @SuppressWarnings("unchecked")
+  protected CustomInstantDeserializer(CustomInstantDeserializer<T> base, DateTimeFormatter f) {
+    super((Class<T>) base.handledType(), f);
+    parsedToValue = base.parsedToValue;
+    fromMilliseconds = base.fromMilliseconds;
+    fromNanoseconds = base.fromNanoseconds;
+    adjust = base.adjust;
+  }
+
+  @Override
+  protected JsonDeserializer<T> withDateFormat(DateTimeFormatter dtf) {
+    if (dtf == _formatter) {
+      return this;
+    }
+    return new CustomInstantDeserializer<T>(this, dtf);
+  }
+
+  @Override
+  public T deserialize(JsonParser parser, DeserializationContext context) throws IOException {
+    //NOTE: Timestamps contain no timezone info, and are always in configured TZ. Only
+    //string values have to be adjusted to the configured TZ.
+    switch (parser.getCurrentTokenId()) {
+      case JsonTokenId.ID_NUMBER_FLOAT: {
+        BigDecimal value = parser.getDecimalValue();
+        long seconds = value.longValue();
+        int nanoseconds = DecimalUtils.extractNanosecondDecimal(value, seconds);
+        return fromNanoseconds.apply(new FromDecimalArguments(
+            seconds, nanoseconds, getZone(context)));
+      }
+
+      case JsonTokenId.ID_NUMBER_INT: {
+        long timestamp = parser.getLongValue();
+        if (context.isEnabled(DeserializationFeature.READ_DATE_TIMESTAMPS_AS_NANOSECONDS)) {
+          return this.fromNanoseconds.apply(new FromDecimalArguments(
+              timestamp, 0, this.getZone(context)
+          ));
+        }
+        return this.fromMilliseconds.apply(new FromIntegerArguments(
+            timestamp, this.getZone(context)
+        ));
+      }
+
+      case JsonTokenId.ID_STRING: {
+        String string = parser.getText().trim();
+        if (string.length() == 0) {
+          return null;
+        }
+        if (string.endsWith("+0000")) {
+          string = string.substring(0, string.length() - 5) + "Z";
+        }
+        T value;
+        try {
+          TemporalAccessor acc = _formatter.parse(string);
+          value = parsedToValue.apply(acc);
+          if (context.isEnabled(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE)) {
+            return adjust.apply(value, this.getZone(context));
+          }
+        } catch (DateTimeException e) {
+          throw _peelDTE(e);
+        }
+        return value;
+      }
+    }
+    throw context.mappingException("Expected type float, integer, or string.");
+  }
+
+  private ZoneId getZone(DeserializationContext context) {
+    // Instants are always in UTC, so don't waste compute cycles
+    return (_valueClass == Instant.class) ? null : DateTimeUtils.toZoneId(context.getTimeZone());
+  }
+
+  private static class FromIntegerArguments {
+    public final long value;
+    public final ZoneId zoneId;
+
+    private FromIntegerArguments(long value, ZoneId zoneId) {
+      this.value = value;
+      this.zoneId = zoneId;
+    }
+  }
+
+  private static class FromDecimalArguments {
+    public final long integer;
+    public final int fraction;
+    public final ZoneId zoneId;
+
+    private FromDecimalArguments(long integer, int fraction, ZoneId zoneId) {
+      this.integer = integer;
+      this.fraction = fraction;
+      this.zoneId = zoneId;
+    }
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/JavaTimeFormatter.java

@@ -0,0 +1,64 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client;
+
+import org.threeten.bp.OffsetDateTime;
+import org.threeten.bp.format.DateTimeFormatter;
+import org.threeten.bp.format.DateTimeParseException;
+
+/**
+ * Class that add parsing/formatting support for Java 8+ {@code OffsetDateTime} class.
+ * It's generated for java clients when {@code AbstractJavaCodegen#dateLibrary} specified as {@code java8}.
+ */
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class JavaTimeFormatter {
+
+    private DateTimeFormatter offsetDateTimeFormatter = DateTimeFormatter.ISO_OFFSET_DATE_TIME;
+
+    /**
+     * Get the date format used to parse/format {@code OffsetDateTime} parameters.
+     * @return DateTimeFormatter
+     */
+    public DateTimeFormatter getOffsetDateTimeFormatter() {
+        return offsetDateTimeFormatter;
+    }
+
+    /**
+     * Set the date format used to parse/format {@code OffsetDateTime} parameters.
+     * @param offsetDateTimeFormatter {@code DateTimeFormatter}
+     */
+    public void setOffsetDateTimeFormatter(DateTimeFormatter offsetDateTimeFormatter) {
+        this.offsetDateTimeFormatter = offsetDateTimeFormatter;
+    }
+
+    /**
+     * Parse the given string into {@code OffsetDateTime} object.
+     * @param str String
+     * @return {@code OffsetDateTime}
+     */
+    public OffsetDateTime parseOffsetDateTime(String str) {
+        try {
+            return OffsetDateTime.parse(str, offsetDateTimeFormatter);
+        } catch (DateTimeParseException e) {
+            throw new RuntimeException(e);
+        }
+    }
+    /**
+     * Format the given {@code OffsetDateTime} object into string.
+     * @param offsetDateTime {@code OffsetDateTime}
+     * @return {@code OffsetDateTime} in string format
+     */
+    public String formatOffsetDateTime(OffsetDateTime offsetDateTime) {
+        return offsetDateTimeFormatter.format(offsetDateTime);
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/Pair.java

@@ -0,0 +1,61 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class Pair {
+    private String name = "";
+    private String value = "";
+
+    public Pair (String name, String value) {
+        setName(name);
+        setValue(value);
+    }
+
+    private void setName(String name) {
+        if (!isValidString(name)) {
+            return;
+        }
+
+        this.name = name;
+    }
+
+    private void setValue(String value) {
+        if (!isValidString(value)) {
+            return;
+        }
+
+        this.value = value;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    public String getValue() {
+        return this.value;
+    }
+
+    private boolean isValidString(String arg) {
+        if (arg == null) {
+            return false;
+        }
+
+        if (arg.trim().isEmpty()) {
+            return false;
+        }
+
+        return true;
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/RFC3339DateFormat.java

@@ -0,0 +1,55 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client;
+
+import com.fasterxml.jackson.databind.util.StdDateFormat;
+
+import java.text.DateFormat;
+import java.text.FieldPosition;
+import java.text.ParsePosition;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.TimeZone;
+
+public class RFC3339DateFormat extends DateFormat {
+  private static final long serialVersionUID = 1L;
+  private static final TimeZone TIMEZONE_Z = TimeZone.getTimeZone("UTC");
+
+  private final StdDateFormat fmt = new StdDateFormat()
+          .withTimeZone(TIMEZONE_Z)
+          .withColonInTimeZone(true);
+
+  public RFC3339DateFormat() {
+    this.calendar = new GregorianCalendar();
+  }
+
+  @Override
+  public Date parse(String source) {
+    return parse(source, new ParsePosition(0));
+  }
+
+  @Override
+  public Date parse(String source, ParsePosition pos) {
+    return fmt.parse(source, pos);
+  }
+
+  @Override
+  public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
+    return fmt.format(date, toAppendTo, fieldPosition);
+  }
+
+  @Override
+  public Object clone() {
+    return this;
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/ServerConfiguration.java

@@ -0,0 +1,58 @@
+package org.openapitools.client;
+
+import java.util.Map;
+
+/**
+ * Representing a Server configuration.
+ */
+public class ServerConfiguration {
+    public String URL;
+    public String description;
+    public Map<String, ServerVariable> variables;
+
+    /**
+     * @param URL A URL to the target host.
+     * @param description A describtion of the host designated by the URL.
+     * @param variables A map between a variable name and its value. The value is used for substitution in the server's URL template.
+     */
+    public ServerConfiguration(String URL, String description, Map<String, ServerVariable> variables) {
+        this.URL = URL;
+        this.description = description;
+        this.variables = variables;
+    }
+
+    /**
+     * Format URL template using given variables.
+     *
+     * @param variables A map between a variable name and its value.
+     * @return Formatted URL.
+     */
+    public String URL(Map<String, String> variables) {
+        String url = this.URL;
+
+        // go through variables and replace placeholders
+        for (Map.Entry<String, ServerVariable> variable: this.variables.entrySet()) {
+            String name = variable.getKey();
+            ServerVariable serverVariable = variable.getValue();
+            String value = serverVariable.defaultValue;
+
+            if (variables != null && variables.containsKey(name)) {
+                value = variables.get(name);
+                if (serverVariable.enumValues.size() > 0 && !serverVariable.enumValues.contains(value)) {
+                    throw new RuntimeException("The variable " + name + " in the server URL has invalid value " + value + ".");
+                }
+            }
+            url = url.replaceAll("\\{" + name + "\\}", value);
+        }
+        return url;
+    }
+
+    /**
+     * Format URL template using default server variables.
+     *
+     * @return Formatted URL.
+     */
+    public String URL() {
+        return URL(null);
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/ServerVariable.java

@@ -0,0 +1,23 @@
+package org.openapitools.client;
+
+import java.util.HashSet;
+
+/**
+ * Representing a Server Variable for server URL template substitution.
+ */
+public class ServerVariable {
+    public String description;
+    public String defaultValue;
+    public HashSet<String> enumValues = null;
+
+    /**
+     * @param description A description for the server variable.
+     * @param defaultValue The default value to use for substitution.
+     * @param enumValues An enumeration of string values to be used if the substitution options are from a limited set.
+     */
+    public ServerVariable(String description, String defaultValue, HashSet<String> enumValues) {
+        this.description = description;
+        this.defaultValue = defaultValue;
+        this.enumValues = enumValues;
+    }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/StringUtil.java

@@ -0,0 +1,83 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client;
+
+import java.util.Collection;
+import java.util.Iterator;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class StringUtil {
+  /**
+   * Check if the given array contains the given value (with case-insensitive comparison).
+   *
+   * @param array The array
+   * @param value The value to search
+   * @return true if the array contains the value
+   */
+  public static boolean containsIgnoreCase(String[] array, String value) {
+    for (String str : array) {
+      if (value == null && str == null) {
+        return true;
+      }
+      if (value != null && value.equalsIgnoreCase(str)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Join an array of strings with the given separator.
+   * <p>
+   * Note: This might be replaced by utility method from commons-lang or guava someday
+   * if one of those libraries is added as dependency.
+   * </p>
+   *
+   * @param array     The array of strings
+   * @param separator The separator
+   * @return the resulting string
+   */
+  public static String join(String[] array, String separator) {
+    int len = array.length;
+    if (len == 0) {
+      return "";
+    }
+
+    StringBuilder out = new StringBuilder();
+    out.append(array[0]);
+    for (int i = 1; i < len; i++) {
+      out.append(separator).append(array[i]);
+    }
+    return out.toString();
+  }
+
+  /**
+   * Join a list of strings with the given separator.
+   *
+   * @param list      The list of strings
+   * @param separator The separator
+   * @return the resulting string
+   */
+  public static String join(Collection<String> list, String separator) {
+    Iterator<String> iterator = list.iterator();
+    StringBuilder out = new StringBuilder();
+    if (iterator.hasNext()) {
+      out.append(iterator.next());
+    }
+    while (iterator.hasNext()) {
+      out.append(separator).append(iterator.next());
+    }
+    return out.toString();
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -0,0 +1,95 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import org.openapitools.client.model.Client;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class AnotherFakeApi {
+  private ApiClient apiClient;
+
+  public AnotherFakeApi() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public AnotherFakeApi(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * To test special tags
+   * To test special tags and operation ID starting with number
+   * @param body client model (required)
+   * @return Client
+   * @throws ApiException if fails to make API call
+   */
+  public Client call123testSpecialTags(Client body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling call123testSpecialTags");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/another-fake/dummy";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<Client> localVarReturnType = new GenericType<Client>() {};
+    return apiClient.invokeAPI(localVarPath, "PATCH", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -0,0 +1,785 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import java.math.BigDecimal;
+import org.openapitools.client.model.Client;
+import java.io.File;
+import org.openapitools.client.model.FileSchemaTestClass;
+import org.threeten.bp.LocalDate;
+import org.threeten.bp.OffsetDateTime;
+import org.openapitools.client.model.OuterComposite;
+import org.openapitools.client.model.User;
+import org.openapitools.client.model.XmlItem;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class FakeApi {
+  private ApiClient apiClient;
+
+  public FakeApi() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public FakeApi(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * creates an XmlItem
+   * this route creates an XmlItem
+   * @param xmlItem XmlItem Body (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void createXmlItem(XmlItem xmlItem) throws ApiException {
+    Object localVarPostBody = xmlItem;
+    
+    // verify the required parameter 'xmlItem' is set
+    if (xmlItem == null) {
+      throw new ApiException(400, "Missing the required parameter 'xmlItem' when calling createXmlItem");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/create_xml_item";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/xml", "application/xml; charset=utf-8", "application/xml; charset=utf-16", "text/xml", "text/xml; charset=utf-8", "text/xml; charset=utf-16"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * 
+   * Test serialization of outer boolean types
+   * @param body Input boolean as post body (optional)
+   * @return Boolean
+   * @throws ApiException if fails to make API call
+   */
+  public Boolean fakeOuterBooleanSerialize(Boolean body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // create path and map variables
+    String localVarPath = "/fake/outer/boolean";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "*/*"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<Boolean> localVarReturnType = new GenericType<Boolean>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * 
+   * Test serialization of object with outer number type
+   * @param body Input composite as post body (optional)
+   * @return OuterComposite
+   * @throws ApiException if fails to make API call
+   */
+  public OuterComposite fakeOuterCompositeSerialize(OuterComposite body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // create path and map variables
+    String localVarPath = "/fake/outer/composite";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "*/*"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<OuterComposite> localVarReturnType = new GenericType<OuterComposite>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * 
+   * Test serialization of outer number types
+   * @param body Input number as post body (optional)
+   * @return BigDecimal
+   * @throws ApiException if fails to make API call
+   */
+  public BigDecimal fakeOuterNumberSerialize(BigDecimal body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // create path and map variables
+    String localVarPath = "/fake/outer/number";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "*/*"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<BigDecimal> localVarReturnType = new GenericType<BigDecimal>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * 
+   * Test serialization of outer string types
+   * @param body Input string as post body (optional)
+   * @return String
+   * @throws ApiException if fails to make API call
+   */
+  public String fakeOuterStringSerialize(String body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // create path and map variables
+    String localVarPath = "/fake/outer/string";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "*/*"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<String> localVarReturnType = new GenericType<String>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * 
+   * For this test, the body for this request much reference a schema named &#x60;File&#x60;.
+   * @param body  (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testBodyWithFileSchema(FileSchemaTestClass body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithFileSchema");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/body-with-file-schema";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "PUT", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * 
+   * 
+   * @param query  (required)
+   * @param body  (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testBodyWithQueryParams(String query, User body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'query' is set
+    if (query == null) {
+      throw new ApiException(400, "Missing the required parameter 'query' when calling testBodyWithQueryParams");
+    }
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling testBodyWithQueryParams");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/body-with-query-params";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarQueryParams.addAll(apiClient.parameterToPair("query", query));
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "PUT", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * To test \&quot;client\&quot; model
+   * To test \&quot;client\&quot; model
+   * @param body client model (required)
+   * @return Client
+   * @throws ApiException if fails to make API call
+   */
+  public Client testClientModel(Client body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling testClientModel");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<Client> localVarReturnType = new GenericType<Client>() {};
+    return apiClient.invokeAPI(localVarPath, "PATCH", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * 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
+   * @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)
+   * @throws ApiException if fails to make API call
+   */
+  public void testEndpointParameters(BigDecimal number, Double _double, String patternWithoutDelimiter, byte[] _byte, Integer integer, Integer int32, Long int64, Float _float, String string, File binary, LocalDate date, OffsetDateTime dateTime, String password, String paramCallback) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'number' is set
+    if (number == null) {
+      throw new ApiException(400, "Missing the required parameter 'number' when calling testEndpointParameters");
+    }
+    
+    // verify the required parameter '_double' is set
+    if (_double == null) {
+      throw new ApiException(400, "Missing the required parameter '_double' when calling testEndpointParameters");
+    }
+    
+    // verify the required parameter 'patternWithoutDelimiter' is set
+    if (patternWithoutDelimiter == null) {
+      throw new ApiException(400, "Missing the required parameter 'patternWithoutDelimiter' when calling testEndpointParameters");
+    }
+    
+    // verify the required parameter '_byte' is set
+    if (_byte == null) {
+      throw new ApiException(400, "Missing the required parameter '_byte' when calling testEndpointParameters");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    if (integer != null)
+      localVarFormParams.put("integer", integer);
+if (int32 != null)
+      localVarFormParams.put("int32", int32);
+if (int64 != null)
+      localVarFormParams.put("int64", int64);
+if (number != null)
+      localVarFormParams.put("number", number);
+if (_float != null)
+      localVarFormParams.put("float", _float);
+if (_double != null)
+      localVarFormParams.put("double", _double);
+if (string != null)
+      localVarFormParams.put("string", string);
+if (patternWithoutDelimiter != null)
+      localVarFormParams.put("pattern_without_delimiter", patternWithoutDelimiter);
+if (_byte != null)
+      localVarFormParams.put("byte", _byte);
+if (binary != null)
+      localVarFormParams.put("binary", binary);
+if (date != null)
+      localVarFormParams.put("date", date);
+if (dateTime != null)
+      localVarFormParams.put("dateTime", dateTime);
+if (password != null)
+      localVarFormParams.put("password", password);
+if (paramCallback != null)
+      localVarFormParams.put("callback", paramCallback);
+
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/x-www-form-urlencoded"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "http_basic_test" };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * To test enum parameters
+   * 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)
+   * @throws ApiException if fails to make API call
+   */
+  public void testEnumParameters(List<String> enumHeaderStringArray, String enumHeaderString, List<String> enumQueryStringArray, String enumQueryString, Integer enumQueryInteger, Double enumQueryDouble, List<String> enumFormStringArray, String enumFormString) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // create path and map variables
+    String localVarPath = "/fake";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "enum_query_string_array", enumQueryStringArray));
+    localVarQueryParams.addAll(apiClient.parameterToPair("enum_query_string", enumQueryString));
+    localVarQueryParams.addAll(apiClient.parameterToPair("enum_query_integer", enumQueryInteger));
+    localVarQueryParams.addAll(apiClient.parameterToPair("enum_query_double", enumQueryDouble));
+
+    if (enumHeaderStringArray != null)
+      localVarHeaderParams.put("enum_header_string_array", apiClient.parameterToString(enumHeaderStringArray));
+if (enumHeaderString != null)
+      localVarHeaderParams.put("enum_header_string", apiClient.parameterToString(enumHeaderString));
+
+    
+    if (enumFormStringArray != null)
+      localVarFormParams.put("enum_form_string_array", enumFormStringArray);
+if (enumFormString != null)
+      localVarFormParams.put("enum_form_string", enumFormString);
+
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/x-www-form-urlencoded"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Fake endpoint to test group parameters (optional)
+   * 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)
+   * @throws ApiException if fails to make API call
+   */
+  public void testGroupParameters(Integer requiredStringGroup, Boolean requiredBooleanGroup, Long requiredInt64Group, Integer stringGroup, Boolean booleanGroup, Long int64Group) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'requiredStringGroup' is set
+    if (requiredStringGroup == null) {
+      throw new ApiException(400, "Missing the required parameter 'requiredStringGroup' when calling testGroupParameters");
+    }
+    
+    // verify the required parameter 'requiredBooleanGroup' is set
+    if (requiredBooleanGroup == null) {
+      throw new ApiException(400, "Missing the required parameter 'requiredBooleanGroup' when calling testGroupParameters");
+    }
+    
+    // verify the required parameter 'requiredInt64Group' is set
+    if (requiredInt64Group == null) {
+      throw new ApiException(400, "Missing the required parameter 'requiredInt64Group' when calling testGroupParameters");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarQueryParams.addAll(apiClient.parameterToPair("required_string_group", requiredStringGroup));
+    localVarQueryParams.addAll(apiClient.parameterToPair("required_int64_group", requiredInt64Group));
+    localVarQueryParams.addAll(apiClient.parameterToPair("string_group", stringGroup));
+    localVarQueryParams.addAll(apiClient.parameterToPair("int64_group", int64Group));
+
+    if (requiredBooleanGroup != null)
+      localVarHeaderParams.put("required_boolean_group", apiClient.parameterToString(requiredBooleanGroup));
+if (booleanGroup != null)
+      localVarHeaderParams.put("boolean_group", apiClient.parameterToString(booleanGroup));
+
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "DELETE", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * test inline additionalProperties
+   * 
+   * @param param request body (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testInlineAdditionalProperties(Map<String, String> param) throws ApiException {
+    Object localVarPostBody = param;
+    
+    // verify the required parameter 'param' is set
+    if (param == null) {
+      throw new ApiException(400, "Missing the required parameter 'param' when calling testInlineAdditionalProperties");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/inline-additionalProperties";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * test json serialization of form data
+   * 
+   * @param param field1 (required)
+   * @param param2 field2 (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testJsonFormData(String param, String param2) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'param' is set
+    if (param == null) {
+      throw new ApiException(400, "Missing the required parameter 'param' when calling testJsonFormData");
+    }
+    
+    // verify the required parameter 'param2' is set
+    if (param2 == null) {
+      throw new ApiException(400, "Missing the required parameter 'param2' when calling testJsonFormData");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/jsonFormData";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    if (param != null)
+      localVarFormParams.put("param", param);
+if (param2 != null)
+      localVarFormParams.put("param2", param2);
+
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/x-www-form-urlencoded"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * 
+   * To test the collection format in query parameters
+   * @param pipe  (required)
+   * @param ioutil  (required)
+   * @param http  (required)
+   * @param url  (required)
+   * @param context  (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testQueryParameterCollectionFormat(List<String> pipe, List<String> ioutil, List<String> http, List<String> url, List<String> context) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'pipe' is set
+    if (pipe == null) {
+      throw new ApiException(400, "Missing the required parameter 'pipe' when calling testQueryParameterCollectionFormat");
+    }
+    
+    // verify the required parameter 'ioutil' is set
+    if (ioutil == null) {
+      throw new ApiException(400, "Missing the required parameter 'ioutil' when calling testQueryParameterCollectionFormat");
+    }
+    
+    // verify the required parameter 'http' is set
+    if (http == null) {
+      throw new ApiException(400, "Missing the required parameter 'http' when calling testQueryParameterCollectionFormat");
+    }
+    
+    // verify the required parameter 'url' is set
+    if (url == null) {
+      throw new ApiException(400, "Missing the required parameter 'url' when calling testQueryParameterCollectionFormat");
+    }
+    
+    // verify the required parameter 'context' is set
+    if (context == null) {
+      throw new ApiException(400, "Missing the required parameter 'context' when calling testQueryParameterCollectionFormat");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/test-query-paramters";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "pipe", pipe));
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "ioutil", ioutil));
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("ssv", "http", http));
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "url", url));
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("multi", "context", context));
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "PUT", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -0,0 +1,95 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import org.openapitools.client.model.Client;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class FakeClassnameTags123Api {
+  private ApiClient apiClient;
+
+  public FakeClassnameTags123Api() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public FakeClassnameTags123Api(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * To test class name in snake case
+   * To test class name in snake case
+   * @param body client model (required)
+   * @return Client
+   * @throws ApiException if fails to make API call
+   */
+  public Client testClassname(Client body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling testClassname");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake_classname_test";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "api_key_query" };
+
+    GenericType<Client> localVarReturnType = new GenericType<Client>() {};
+    return apiClient.invokeAPI(localVarPath, "PATCH", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/PetApi.java

@@ -0,0 +1,481 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import java.io.File;
+import org.openapitools.client.model.ModelApiResponse;
+import org.openapitools.client.model.Pet;
+import java.util.Set;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class PetApi {
+  private ApiClient apiClient;
+
+  public PetApi() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public PetApi(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * Add a new pet to the store
+   * 
+   * @param body Pet object that needs to be added to the store (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void addPet(Pet body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling addPet");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json", "application/xml"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Deletes a pet
+   * 
+   * @param petId Pet id to delete (required)
+   * @param apiKey  (optional)
+   * @throws ApiException if fails to make API call
+   */
+  public void deletePet(Long petId, String apiKey) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'petId' is set
+    if (petId == null) {
+      throw new ApiException(400, "Missing the required parameter 'petId' when calling deletePet");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/{petId}"
+      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    if (apiKey != null)
+      localVarHeaderParams.put("api_key", apiClient.parameterToString(apiKey));
+
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+
+    apiClient.invokeAPI(localVarPath, "DELETE", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Finds Pets by status
+   * Multiple status values can be provided with comma separated strings
+   * @param status Status values that need to be considered for filter (required)
+   * @return List&lt;Pet&gt;
+   * @throws ApiException if fails to make API call
+   */
+  public List<Pet> findPetsByStatus(List<String> status) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'status' is set
+    if (status == null) {
+      throw new ApiException(400, "Missing the required parameter 'status' when calling findPetsByStatus");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/findByStatus";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "status", status));
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+    GenericType<List<Pet>> localVarReturnType = new GenericType<List<Pet>>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Finds Pets by tags
+   * Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+   * @param tags Tags to filter by (required)
+   * @return Set&lt;Pet&gt;
+   * @throws ApiException if fails to make API call
+   * @deprecated
+   */
+  @Deprecated
+  public Set<Pet> findPetsByTags(Set<String> tags) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'tags' is set
+    if (tags == null) {
+      throw new ApiException(400, "Missing the required parameter 'tags' when calling findPetsByTags");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/findByTags";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarCollectionQueryParams.addAll(apiClient.parameterToPairs("csv", "tags", tags));
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+    GenericType<Set<Pet>> localVarReturnType = new GenericType<Set<Pet>>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Find pet by ID
+   * Returns a single pet
+   * @param petId ID of pet to return (required)
+   * @return Pet
+   * @throws ApiException if fails to make API call
+   */
+  public Pet getPetById(Long petId) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'petId' is set
+    if (petId == null) {
+      throw new ApiException(400, "Missing the required parameter 'petId' when calling getPetById");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/{petId}"
+      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "api_key" };
+
+    GenericType<Pet> localVarReturnType = new GenericType<Pet>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Update an existing pet
+   * 
+   * @param body Pet object that needs to be added to the store (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void updatePet(Pet body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling updatePet");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json", "application/xml"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+
+    apiClient.invokeAPI(localVarPath, "PUT", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Updates a pet in the store with form data
+   * 
+   * @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)
+   * @throws ApiException if fails to make API call
+   */
+  public void updatePetWithForm(Long petId, String name, String status) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'petId' is set
+    if (petId == null) {
+      throw new ApiException(400, "Missing the required parameter 'petId' when calling updatePetWithForm");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/{petId}"
+      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    if (name != null)
+      localVarFormParams.put("name", name);
+if (status != null)
+      localVarFormParams.put("status", status);
+
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/x-www-form-urlencoded"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * uploads an image
+   * 
+   * @param petId ID of pet to update (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @param file file to upload (optional)
+   * @return ModelApiResponse
+   * @throws ApiException if fails to make API call
+   */
+  public ModelApiResponse uploadFile(Long petId, String additionalMetadata, File file) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'petId' is set
+    if (petId == null) {
+      throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFile");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/pet/{petId}/uploadImage"
+      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    if (additionalMetadata != null)
+      localVarFormParams.put("additionalMetadata", additionalMetadata);
+if (file != null)
+      localVarFormParams.put("file", file);
+
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "multipart/form-data"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+    GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * uploads an image (required)
+   * 
+   * @param petId ID of pet to update (required)
+   * @param requiredFile file to upload (required)
+   * @param additionalMetadata Additional data to pass to server (optional)
+   * @return ModelApiResponse
+   * @throws ApiException if fails to make API call
+   */
+  public ModelApiResponse uploadFileWithRequiredFile(Long petId, File requiredFile, String additionalMetadata) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'petId' is set
+    if (petId == null) {
+      throw new ApiException(400, "Missing the required parameter 'petId' when calling uploadFileWithRequiredFile");
+    }
+    
+    // verify the required parameter 'requiredFile' is set
+    if (requiredFile == null) {
+      throw new ApiException(400, "Missing the required parameter 'requiredFile' when calling uploadFileWithRequiredFile");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/{petId}/uploadImageWithRequiredFile"
+      .replaceAll("\\{" + "petId" + "\\}", apiClient.escapeString(petId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    if (additionalMetadata != null)
+      localVarFormParams.put("additionalMetadata", additionalMetadata);
+if (requiredFile != null)
+      localVarFormParams.put("requiredFile", requiredFile);
+
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "multipart/form-data"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "petstore_auth" };
+
+    GenericType<ModelApiResponse> localVarReturnType = new GenericType<ModelApiResponse>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -0,0 +1,222 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import org.openapitools.client.model.Order;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class StoreApi {
+  private ApiClient apiClient;
+
+  public StoreApi() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public StoreApi(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * Delete purchase order by ID
+   * For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
+   * @param orderId ID of the order that needs to be deleted (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void deleteOrder(String orderId) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'orderId' is set
+    if (orderId == null) {
+      throw new ApiException(400, "Missing the required parameter 'orderId' when calling deleteOrder");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/store/order/{order_id}"
+      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "DELETE", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Returns pet inventories by status
+   * Returns a map of status codes to quantities
+   * @return Map&lt;String, Integer&gt;
+   * @throws ApiException if fails to make API call
+   */
+  public Map<String, Integer> getInventory() throws ApiException {
+    Object localVarPostBody = null;
+    
+    // create path and map variables
+    String localVarPath = "/store/inventory";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] { "api_key" };
+
+    GenericType<Map<String, Integer>> localVarReturnType = new GenericType<Map<String, Integer>>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Find purchase order by ID
+   * 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 Order
+   * @throws ApiException if fails to make API call
+   */
+  public Order getOrderById(Long orderId) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'orderId' is set
+    if (orderId == null) {
+      throw new ApiException(400, "Missing the required parameter 'orderId' when calling getOrderById");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/store/order/{order_id}"
+      .replaceAll("\\{" + "order_id" + "\\}", apiClient.escapeString(orderId.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<Order> localVarReturnType = new GenericType<Order>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Place an order for a pet
+   * 
+   * @param body order placed for purchasing the pet (required)
+   * @return Order
+   * @throws ApiException if fails to make API call
+   */
+  public Order placeOrder(Order body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling placeOrder");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/store/order";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<Order> localVarReturnType = new GenericType<Order>() {};
+    return apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/UserApi.java

@@ -0,0 +1,408 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package org.openapitools.client.api;
+
+import com.sun.jersey.api.client.GenericType;
+
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.model.*;
+import org.openapitools.client.Pair;
+
+import org.openapitools.client.model.User;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class UserApi {
+  private ApiClient apiClient;
+
+  public UserApi() {
+    this(Configuration.getDefaultApiClient());
+  }
+
+  public UserApi(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  public ApiClient getApiClient() {
+    return apiClient;
+  }
+
+  public void setApiClient(ApiClient apiClient) {
+    this.apiClient = apiClient;
+  }
+
+  /**
+   * Create user
+   * This can only be done by the logged in user.
+   * @param body Created user object (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void createUser(User body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling createUser");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Creates list of users with given input array
+   * 
+   * @param body List of user object (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void createUsersWithArrayInput(List<User> body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithArrayInput");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/createWithArray";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Creates list of users with given input array
+   * 
+   * @param body List of user object (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void createUsersWithListInput(List<User> body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling createUsersWithListInput");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/createWithList";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Delete user
+   * This can only be done by the logged in user.
+   * @param username The name that needs to be deleted (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void deleteUser(String username) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'username' is set
+    if (username == null) {
+      throw new ApiException(400, "Missing the required parameter 'username' when calling deleteUser");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/{username}"
+      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "DELETE", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Get user by user name
+   * 
+   * @param username The name that needs to be fetched. Use user1 for testing. (required)
+   * @return User
+   * @throws ApiException if fails to make API call
+   */
+  public User getUserByName(String username) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'username' is set
+    if (username == null) {
+      throw new ApiException(400, "Missing the required parameter 'username' when calling getUserByName");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/{username}"
+      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<User> localVarReturnType = new GenericType<User>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Logs user into the system
+   * 
+   * @param username The user name for login (required)
+   * @param password The password for login in clear text (required)
+   * @return String
+   * @throws ApiException if fails to make API call
+   */
+  public String loginUser(String username, String password) throws ApiException {
+    Object localVarPostBody = null;
+    
+    // verify the required parameter 'username' is set
+    if (username == null) {
+      throw new ApiException(400, "Missing the required parameter 'username' when calling loginUser");
+    }
+    
+    // verify the required parameter 'password' is set
+    if (password == null) {
+      throw new ApiException(400, "Missing the required parameter 'password' when calling loginUser");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/login";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    localVarQueryParams.addAll(apiClient.parameterToPair("username", username));
+    localVarQueryParams.addAll(apiClient.parameterToPair("password", password));
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      "application/xml", "application/json"
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    GenericType<String> localVarReturnType = new GenericType<String>() {};
+    return apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
+      }
+  /**
+   * Logs out current logged in user session
+   * 
+   * @throws ApiException if fails to make API call
+   */
+  public void logoutUser() throws ApiException {
+    Object localVarPostBody = null;
+    
+    // create path and map variables
+    String localVarPath = "/user/logout";
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "GET", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+  /**
+   * Updated user
+   * 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)
+   * @throws ApiException if fails to make API call
+   */
+  public void updateUser(String username, User body) throws ApiException {
+    Object localVarPostBody = body;
+    
+    // verify the required parameter 'username' is set
+    if (username == null) {
+      throw new ApiException(400, "Missing the required parameter 'username' when calling updateUser");
+    }
+    
+    // verify the required parameter 'body' is set
+    if (body == null) {
+      throw new ApiException(400, "Missing the required parameter 'body' when calling updateUser");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/user/{username}"
+      .replaceAll("\\{" + "username" + "\\}", apiClient.escapeString(username.toString()));
+
+    // query params
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+
+    
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+
+    apiClient.invokeAPI(localVarPath, "PUT", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAccept, localVarContentType, localVarAuthNames, null);
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/auth/ApiKeyAuth.java

@@ -0,0 +1,77 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.auth;
+
+import org.openapitools.client.Pair;
+
+import java.util.Map;
+import java.util.List;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class ApiKeyAuth implements Authentication {
+  private final String location;
+  private final String paramName;
+
+  private String apiKey;
+  private String apiKeyPrefix;
+
+  public ApiKeyAuth(String location, String paramName) {
+    this.location = location;
+    this.paramName = paramName;
+  }
+
+  public String getLocation() {
+    return location;
+  }
+
+  public String getParamName() {
+    return paramName;
+  }
+
+  public String getApiKey() {
+    return apiKey;
+  }
+
+  public void setApiKey(String apiKey) {
+    this.apiKey = apiKey;
+  }
+
+  public String getApiKeyPrefix() {
+    return apiKeyPrefix;
+  }
+
+  public void setApiKeyPrefix(String apiKeyPrefix) {
+    this.apiKeyPrefix = apiKeyPrefix;
+  }
+
+  @Override
+  public void applyToParams(List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams) {
+    if (apiKey == null) {
+      return;
+    }
+    String value;
+    if (apiKeyPrefix != null) {
+      value = apiKeyPrefix + " " + apiKey;
+    } else {
+      value = apiKey;
+    }
+    if ("query".equals(location)) {
+      queryParams.add(new Pair(paramName, value));
+    } else if ("header".equals(location)) {
+      headerParams.put(paramName, value);
+    } else if ("cookie".equals(location)) {
+      cookieParams.put(paramName, value);
+    }
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/auth/Authentication.java

@@ -0,0 +1,30 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.auth;
+
+import org.openapitools.client.Pair;
+
+import java.util.Map;
+import java.util.List;
+
+public interface Authentication {
+    /**
+     * Apply authentication settings to header and query params.
+     *
+     * @param queryParams List of query parameters
+     * @param headerParams Map of header parameters
+     * @param cookieParams Map of cookie parameters
+     */
+    void applyToParams(List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams);
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java

@@ -0,0 +1,54 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.auth;
+
+import org.openapitools.client.Pair;
+
+import java.util.Base64;
+import java.nio.charset.StandardCharsets;
+
+import java.util.Map;
+import java.util.List;
+
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class HttpBasicAuth implements Authentication {
+  private String username;
+  private String password;
+
+  public String getUsername() {
+    return username;
+  }
+
+  public void setUsername(String username) {
+    this.username = username;
+  }
+
+  public String getPassword() {
+    return password;
+  }
+
+  public void setPassword(String password) {
+    this.password = password;
+  }
+
+  @Override
+  public void applyToParams(List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams) {
+    if (username == null && password == null) {
+      return;
+    }
+    String str = (username == null ? "" : username) + ":" + (password == null ? "" : password);
+    headerParams.put("Authorization", "Basic " + Base64.getEncoder().encodeToString(str.getBytes(StandardCharsets.UTF_8)));
+  }
+}

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java

@@ -0,0 +1,60 @@
+/*
+ * OpenAPI Petstore
+ * This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: \" \\
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.openapitools.client.auth;
+
+import org.openapitools.client.Pair;
+
+import java.util.Map;
+import java.util.List;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class HttpBearerAuth implements Authentication {
+  private final String scheme;
+  private String bearerToken;
+
+  public HttpBearerAuth(String scheme) {
+    this.scheme = scheme;
+  }
+
+  /**
+   * Gets the token, which together with the scheme, will be sent as the value of the Authorization header.
+   *
+   * @return The bearer token
+   */
+  public String getBearerToken() {
+    return bearerToken;
+  }
+
+  /**
+   * Sets the token, which together with the scheme, will be sent as the value of the Authorization header.
+   *
+   * @param bearerToken The bearer token to send in the Authorization header
+   */
+  public void setBearerToken(String bearerToken) {
+    this.bearerToken = bearerToken;
+  }
+
+  @Override
+  public void applyToParams(List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams) {
+    if(bearerToken == null) {
+      return;
+    }
+
+    headerParams.put("Authorization", (scheme != null ? upperCaseBearer(scheme) + " " : "") + bearerToken);
+  }
+
+  private static String upperCaseBearer(String scheme) {
+    return ("bearer".equalsIgnoreCase(scheme)) ? "Bearer" : scheme;
+  }
+}