[JAVA] fix: oneOf generates incorrect model for primitive types (#16834)

* generate samples

* try fix

* add new sample for fixed case

* also improve native library

Other libraries don't need fixes.

* add oneOf_twoPrimitives.yaml

* generate samples

* resolve comment

.github/workflows/samples-java-client-jdk11.yaml

@@ -10,6 +10,7 @@ on:
       - samples/openapi3/client/petstore/java/jersey2-java8-swagger1/**
       - samples/openapi3/client/petstore/java/jersey2-java8-swagger2/**
       - samples/openapi3/client/petstore/java/native**
+      - samples/client/others/java/okhttp-gson-oneOf/**
       - samples/client/others/java/resttemplate-useAbstractionForFiles/**
       - samples/client/others/java/webclient-useAbstractionForFiles/**
   pull_request:
@@ -21,6 +22,7 @@ on:
       - samples/openapi3/client/petstore/java/jersey2-java8-swagger1/**
       - samples/openapi3/client/petstore/java/jersey2-java8-swagger2/**
       - samples/openapi3/client/petstore/java/native**
+      - samples/client/others/java/okhttp-gson-oneOf/**
       - samples/client/others/java/resttemplate-useAbstractionForFiles/**
       - samples/client/others/java/webclient-useAbstractionForFiles/**
 jobs:
@@ -65,6 +67,7 @@ jobs:
           - samples/client/petstore/java/okhttp-gson-swagger2/
           - samples/client/petstore/java/resttemplate-swagger2/
           - samples/openapi3/client/petstore/java/jersey2-java8-swagger2/
+          - samples/client/others/java/okhttp-gson-oneOf/
           - samples/client/others/java/resttemplate-useAbstractionForFiles/
           - samples/client/others/java/webclient-useAbstractionForFiles/
     steps:

bin/configs/java-okhttp-gson-oneOf.yaml

@@ -0,0 +1,7 @@
+generatorName: java
+outputDir: samples/client/others/java/okhttp-gson-oneOf
+library: okhttp-gson
+inputSpec: modules/openapi-generator/src/test/resources/3_0/oneOf_twoPrimitives.yaml
+templateDir: modules/openapi-generator/src/main/resources/Java
+additionalProperties:
+  hideGenerationTimestamp: "true"

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

@@ -7248,7 +7248,7 @@ public class DefaultCodegen implements CodegenConfig {
                     codegenParameter.description = codegenModelDescription;
                     imports.add(codegenParameter.baseType);
 
-                    if (codegenProperty.complexType != null) {
+                    if (codegenProperty.complexType != null && codegenProperty.getComposedSchemas() == null) {
                         imports.add(codegenProperty.complexType);
                     }
                 }

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

@@ -231,6 +231,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     StringJoiner joiner = new StringJoiner("&");
 
     {{#composedSchemas.oneOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     if (getActualInstance() instanceof {{{dataType}}}) {
         {{#isArray}}
         {{#items.isPrimitiveType}}
@@ -352,6 +353,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isArray}}
         return joiner.toString();
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/composedSchemas.oneOf}}
     return null;
   }

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

@@ -264,6 +264,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     StringJoiner joiner = new StringJoiner("&");
 
     {{#composedSchemas.oneOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     if (getActualInstance() instanceof {{{dataType}}}) {
         {{#isArray}}
         {{#items.isPrimitiveType}}
@@ -385,6 +386,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isArray}}
         return joiner.toString();
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/composedSchemas.oneOf}}
     return null;
   }

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

@@ -48,7 +48,9 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
             {{#composedSchemas}}
             {{#anyOf}}
             {{^isArray}}
+            {{^vendorExtensions.x-duplicated-data-type}}
             final TypeAdapter<{{{dataType}}}> adapter{{{dataType}}} = gson.getDelegateAdapter(this, TypeToken.get({{{dataType}}}.class));
+            {{/vendorExtensions.x-duplicated-data-type}}
             {{/isArray}}
             {{#isArray}}
 
@@ -68,6 +70,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
                     {{#composedSchemas}}
                     {{#anyOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
                     // check if the actual instance is of the type `{{{dataType}}}`
                     if (value.getActualInstance() instanceof {{#isArray}}List<?>{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}) {
                     {{#isPrimitiveType}}
@@ -91,6 +94,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                     {{/isPrimitiveType}}
                     {{/isArray}}
                     }
+                    {{/vendorExtensions.x-duplicated-data-type}}
                     {{/anyOf}}
                     {{/composedSchemas}}
                     throw new IOException("Failed to serialize as the type doesn't match anyOf schemae: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}");
@@ -106,6 +110,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
                     {{#composedSchemas}}
                     {{#anyOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
                     {{^hasVars}}
                     // deserialize {{{dataType}}}
                     try {
@@ -184,6 +189,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                         log.log(Level.FINER, "Input data does not match schema '{{{.}}}'", e);
                     }
                     {{/hasVars}}
+                    {{/vendorExtensions.x-duplicated-data-type}}
                     {{/anyOf}}
                     {{/composedSchemas}}
 
@@ -210,7 +216,9 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     static {
         {{#composedSchemas}}
         {{#anyOf}}
+        {{^vendorExtensions.x-duplicated-data-type}}
         schemas.put("{{{dataType}}}", {{{baseType}}}.class);
+        {{/vendorExtensions.x-duplicated-data-type}}
         {{/anyOf}}
         {{/composedSchemas}}
     }
@@ -238,6 +246,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isNullable}}
         {{#composedSchemas}}
         {{#anyOf}}
+        {{^vendorExtensions.x-duplicated-data-type}}
         if (instance instanceof {{#isArray}}List<?>{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}) {
         {{#isArray}}
             List<?> list = (List<?>) instance;
@@ -252,6 +261,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isArray}}
         }
 
+        {{/vendorExtensions.x-duplicated-data-type}}
         {{/anyOf}}
         {{/composedSchemas}}
         throw new RuntimeException("Invalid instance type. Must be {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}");
@@ -270,6 +280,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
     {{#composedSchemas}}
     {{#anyOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     /**
      * Get the actual instance of `{{{dataType}}}`. If the actual instance is not `{{{dataType}}}`,
      * the ClassCastException will be thrown.
@@ -280,6 +291,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     public {{{dataType}}} get{{#isArray}}{{complexType}}List{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}() throws ClassCastException {
         return ({{{dataType}}})super.getActualInstance();
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/anyOf}}
     {{/composedSchemas}}
 
@@ -294,6 +306,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     ArrayList<String> errorMessages = new ArrayList<>();
     {{#composedSchemas}}
     {{#anyOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     // validate the json string with {{{dataType}}}
     try {
     {{^hasVars}}
@@ -350,6 +363,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
       errorMessages.add(String.format("Deserialization for {{{dataType}}} failed with `%s`.", e.getMessage()));
       // continue to the next one
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/anyOf}}
     {{/composedSchemas}}
     throw new IOException(String.format("The JSON string is invalid for {{classname}} with anyOf schemas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. no class match the result, expected at least 1. Detailed failure message for anyOf schemas: %s. JSON: %s", errorMessages, jsonElement.toString()));

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

@@ -48,7 +48,9 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
             {{#composedSchemas}}
             {{#oneOf}}
             {{^isArray}}
+            {{^vendorExtensions.x-duplicated-data-type}}
             final TypeAdapter<{{{dataType}}}> adapter{{{dataType}}} = gson.getDelegateAdapter(this, TypeToken.get({{{dataType}}}.class));
+            {{/vendorExtensions.x-duplicated-data-type}}
             {{/isArray}}
             {{#isArray}}
 
@@ -68,6 +70,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
                     {{#composedSchemas}}
                     {{#oneOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
                     // check if the actual instance is of the type `{{{dataType}}}`
                     if (value.getActualInstance() instanceof {{#isArray}}List<?>{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}) {
                     {{#isPrimitiveType}}
@@ -91,6 +94,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                     {{/isPrimitiveType}}
                     {{/isArray}}
                     }
+                    {{/vendorExtensions.x-duplicated-data-type}}
                     {{/oneOf}}
                     {{/composedSchemas}}
                     throw new IOException("Failed to serialize as the type doesn't match oneOf schemas: {{#oneOf}}{{{.}}}{{^-last}}, {{/-last}}{{/oneOf}}");
@@ -131,6 +135,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
                     {{#composedSchemas}}
                     {{#oneOf}}
+                    {{^vendorExtensions.x-duplicated-data-type}}
                     {{^hasVars}}
                     // deserialize {{{dataType}}}
                     try {
@@ -206,6 +211,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                         log.log(Level.FINER, "Input data does not match schema '{{{.}}}'", e);
                     }
                     {{/hasVars}}
+                    {{/vendorExtensions.x-duplicated-data-type}}
                     {{/oneOf}}
                     {{/composedSchemas}}
 
@@ -238,7 +244,9 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     static {
         {{#composedSchemas}}
         {{#oneOf}}
+        {{^vendorExtensions.x-duplicated-data-type}}
         schemas.put("{{{dataType}}}", {{{baseType}}}.class);
+        {{/vendorExtensions.x-duplicated-data-type}}
         {{/oneOf}}
         {{/composedSchemas}}
     }
@@ -266,6 +274,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isNullable}}
         {{#composedSchemas}}
         {{#oneOf}}
+        {{^vendorExtensions.x-duplicated-data-type}}
         if (instance instanceof {{#isArray}}List<?>{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}) {
         {{#isArray}}
             List<?> list = (List<?>) instance;
@@ -280,6 +289,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
         {{/isArray}}
         }
 
+        {{/vendorExtensions.x-duplicated-data-type}}
         {{/oneOf}}
         {{/composedSchemas}}
         throw new RuntimeException("Invalid instance type. Must be {{#oneOf}}{{{.}}}{{^-last}}, {{/-last}}{{/oneOf}}");
@@ -298,6 +308,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
     {{#composedSchemas}}
     {{#oneOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     /**
      * Get the actual instance of `{{{dataType}}}`. If the actual instance is not `{{{dataType}}}`,
      * the ClassCastException will be thrown.
@@ -308,6 +319,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     public {{{dataType}}} get{{#isArray}}{{complexType}}List{{/isArray}}{{^isArray}}{{{dataType}}}{{/isArray}}() throws ClassCastException {
         return ({{{dataType}}})super.getActualInstance();
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/oneOf}}
     {{/composedSchemas}}
 
@@ -323,6 +335,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     ArrayList<String> errorMessages = new ArrayList<>();
     {{#composedSchemas}}
     {{#oneOf}}
+    {{^vendorExtensions.x-duplicated-data-type}}
     // validate the json string with {{{dataType}}}
     try {
     {{^hasVars}}
@@ -379,6 +392,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
       errorMessages.add(String.format("Deserialization for {{{dataType}}} failed with `%s`.", e.getMessage()));
       // continue to the next one
     }
+    {{/vendorExtensions.x-duplicated-data-type}}
     {{/oneOf}}
     {{/composedSchemas}}
     if (validCount != 1) {

modules/openapi-generator/src/test/resources/3_0/oneOf_twoPrimitives.yaml

@@ -0,0 +1,20 @@
+openapi: 3.0.3
+info:
+  title: oneOf two primitives
+  description: oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+  version: 1.0.0
+paths:
+  /myExample:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              oneOf:
+                - type: string
+                  format: ipv4
+                - type: string
+                  format: ipv6
+      responses:
+        200:
+          description: OK

samples/client/others/java/okhttp-gson-oneOf/.github/workflows/maven.yml

@@ -0,0 +1,30 @@
+# This workflow will build a Java project with Maven, and cache/restore any dependencies to improve the workflow execution time
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
+#
+# This file is auto-generated by OpenAPI Generator (https://openapi-generator.tech)
+
+name: Java CI with Maven
+
+on:
+  push:
+    branches: [ main, master ]
+  pull_request:
+    branches: [ main, master ]
+
+jobs:
+  build:
+    name: Build oneOf two primitives
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ '8' ]
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK
+      uses: actions/setup-java@v2
+      with:
+        java-version: ${{ matrix.java }}
+        distribution: 'temurin'
+        cache: maven
+    - name: Build with Maven
+      run: mvn -B package --no-transfer-progress --file pom.xml

samples/client/others/java/okhttp-gson-oneOf/.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/others/java/okhttp-gson-oneOf/.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/others/java/okhttp-gson-oneOf/.openapi-generator/FILES

@@ -0,0 +1,38 @@
+.github/workflows/maven.yml
+.gitignore
+.travis.yml
+README.md
+api/openapi.yaml
+build.gradle
+build.sbt
+docs/DefaultApi.md
+docs/MyExamplePostRequest.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/ApiCallback.java
+src/main/java/org/openapitools/client/ApiClient.java
+src/main/java/org/openapitools/client/ApiException.java
+src/main/java/org/openapitools/client/ApiResponse.java
+src/main/java/org/openapitools/client/Configuration.java
+src/main/java/org/openapitools/client/GzipRequestInterceptor.java
+src/main/java/org/openapitools/client/JSON.java
+src/main/java/org/openapitools/client/Pair.java
+src/main/java/org/openapitools/client/ProgressRequestBody.java
+src/main/java/org/openapitools/client/ProgressResponseBody.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/DefaultApi.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/model/AbstractOpenApiSchema.java
+src/main/java/org/openapitools/client/model/MyExamplePostRequest.java

samples/client/others/java/okhttp-gson-oneOf/.openapi-generator/VERSION

@@ -0,0 +1 @@
+7.1.0-SNAPSHOT

samples/client/others/java/okhttp-gson-oneOf/.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/others/java/okhttp-gson-oneOf/README.md

@@ -0,0 +1,136 @@
+# openapi-java-client
+
+oneOf two primitives
+- API version: 1.0.0
+
+oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+
+
+*Automatically generated by the [OpenAPI Generator](https://openapi-generator.tech)*
+
+
+## Requirements
+
+Building the API client library requires:
+1. Java 1.8+
+2. Maven (3.8.3+)/Gradle (7.2+)
+
+## 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>openapi-java-client</artifactId>
+  <version>1.0.0</version>
+  <scope>compile</scope>
+</dependency>
+```
+
+### Gradle users
+
+Add this dependency to your project's build file:
+
+```groovy
+  repositories {
+    mavenCentral()     // Needed if the 'openapi-java-client' jar has been published to maven central.
+    mavenLocal()       // Needed if the 'openapi-java-client' jar has been published to the local maven repo.
+  }
+
+  dependencies {
+     implementation "org.openapitools:openapi-java-client:1.0.0"
+  }
+```
+
+### Others
+
+At first generate the JAR by executing:
+
+```shell
+mvn clean package
+```
+
+Then manually install the following JARs:
+
+* `target/openapi-java-client-1.0.0.jar`
+* `target/lib/*.jar`
+
+## Getting Started
+
+Please follow the [installation](#installation) instruction and execute the following Java code:
+
+```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.DefaultApi;
+
+public class Example {
+  public static void main(String[] args) {
+    ApiClient defaultClient = Configuration.getDefaultApiClient();
+    defaultClient.setBasePath("http://localhost");
+
+    DefaultApi apiInstance = new DefaultApi(defaultClient);
+    MyExamplePostRequest myExamplePostRequest = new MyExamplePostRequest(); // MyExamplePostRequest | 
+    try {
+      apiInstance.myExamplePost(myExamplePostRequest);
+    } catch (ApiException e) {
+      System.err.println("Exception when calling DefaultApi#myExamplePost");
+      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://localhost*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*DefaultApi* | [**myExamplePost**](docs/DefaultApi.md#myExamplePost) | **POST** /myExample | 
+
+
+## Documentation for Models
+
+ - [MyExamplePostRequest](docs/MyExamplePostRequest.md)
+
+
+<a id="documentation-for-authorization"></a>
+## Documentation for Authorization
+
+Endpoints do not require authorization.
+
+
+## Recommendation
+
+It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issues.
+
+## Author
+
+
+

samples/client/others/java/okhttp-gson-oneOf/api/openapi.yaml

@@ -0,0 +1,29 @@
+openapi: 3.0.3
+info:
+  description: "oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450"
+  title: oneOf two primitives
+  version: 1.0.0
+servers:
+- url: /
+paths:
+  /myExample:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/_myExample_post_request'
+      responses:
+        "200":
+          description: OK
+      x-content-type: application/json
+      x-accepts: application/json
+components:
+  schemas:
+    _myExample_post_request:
+      oneOf:
+      - format: ipv4
+        type: string
+      - format: ipv6
+        type: string
+

samples/client/others/java/okhttp-gson-oneOf/build.gradle

@@ -0,0 +1,168 @@
+apply plugin: 'idea'
+apply plugin: 'eclipse'
+apply plugin: 'java'
+apply plugin: 'com.diffplug.spotless'
+
+group = 'org.openapitools'
+version = '1.0.0'
+
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:2.3.+'
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:2.1'
+        classpath 'com.diffplug.spotless:spotless-plugin-gradle:6.11.0'
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+sourceSets {
+    main.java.srcDirs = ['src/main/java']
+}
+
+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}-${version}.aar"
+                    output.outputFile = new File(outputFile.parent, fileName)
+                }
+            }
+        }
+
+        dependencies {
+            provided "jakarta.annotation:jakarta.annotation-api:$jakarta_annotation_version"
+        }
+    }
+
+    afterEvaluate {
+        android.libraryVariants.all { variant ->
+            def task = project.tasks.create "jar${variant.name.capitalize()}", Jar
+            task.description = "Create jar artifact for ${variant.name}"
+            task.dependsOn variant.javaCompile
+            task.from variant.javaCompile.destinationDirectory
+            task.destinationDirectory = project.file("${project.buildDir}/outputs/jar")
+            task.archiveFileName = "${project.name}-${variant.baseName}-${version}.jar"
+            artifacts.add('archives', task)
+        }
+    }
+
+    task sourcesJar(type: Jar) {
+        from android.sourceSets.main.java.srcDirs
+        classifier = 'sources'
+    }
+
+    artifacts {
+        archives sourcesJar
+    }
+
+} else {
+
+    apply plugin: 'java'
+    apply plugin: 'maven-publish'
+
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+
+    publishing {
+        publications {
+            maven(MavenPublication) {
+               artifactId = 'openapi-java-client'
+               from components.java
+            }
+        }
+    }
+
+    task execute(type:JavaExec) {
+       main = System.getProperty('mainClass')
+       classpath = sourceSets.main.runtimeClasspath
+    }
+}
+
+ext {
+    jakarta_annotation_version = "1.3.5"
+}
+
+dependencies {
+    implementation 'io.swagger:swagger-annotations:1.6.8'
+    implementation "com.google.code.findbugs:jsr305:3.0.2"
+    implementation 'com.squareup.okhttp3:okhttp:4.10.0'
+    implementation 'com.squareup.okhttp3:logging-interceptor:4.10.0'
+    implementation 'com.google.code.gson:gson:2.9.1'
+    implementation 'io.gsonfire:gson-fire:1.8.5'
+    implementation 'javax.ws.rs:jsr311-api:1.1.1'
+    implementation 'javax.ws.rs:javax.ws.rs-api:2.1.1'
+    implementation 'org.openapitools:jackson-databind-nullable:0.2.6'
+    implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.12.0'
+    implementation "jakarta.annotation:jakarta.annotation-api:$jakarta_annotation_version"
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.9.1'
+    testImplementation 'org.mockito:mockito-core:3.12.4'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.9.1'
+}
+
+javadoc {
+    options.tags = [ "http.response.details:a:Http Response Details" ]
+}
+
+// Use spotless plugin to automatically format code, remove unused import, etc
+// To apply changes directly to the file, run `gradlew spotlessApply`
+// Ref: https://github.com/diffplug/spotless/tree/main/plugin-gradle
+spotless {
+    // comment out below to run spotless as part of the `check` task
+    enforceCheck false
+
+    format 'misc', {
+        // define the files (e.g. '*.gradle', '*.md') to apply `misc` to
+        target '.gitignore'
+
+        // define the steps to apply to those files
+        trimTrailingWhitespace()
+        indentWithSpaces() // Takes an integer argument if you don't like 4
+        endWithNewline()
+    }
+    java {
+        // don't need to set target, it is inferred from java
+
+        // apply a specific flavor of google-java-format
+        googleJavaFormat('1.8').aosp().reflowLongStrings()
+
+        removeUnusedImports()
+        importOrder()
+    }
+}
+
+test {
+    // Enable JUnit 5 (Gradle 4.6+).
+    useJUnitPlatform()
+
+    // Always run tests, even when nothing changed.
+    dependsOn 'cleanTest'
+
+    // Show test results.
+    testLogging {
+        events "passed", "skipped", "failed"
+    }
+
+}

samples/client/others/java/okhttp-gson-oneOf/build.sbt

@@ -0,0 +1,28 @@
+lazy val root = (project in file(".")).
+  settings(
+    organization := "org.openapitools",
+    name := "openapi-java-client",
+    version := "1.0.0",
+    scalaVersion := "2.11.4",
+    scalacOptions ++= Seq("-feature"),
+    javacOptions in compile ++= Seq("-Xlint:deprecation"),
+    publishArtifact in (Compile, packageDoc) := false,
+    resolvers += Resolver.mavenLocal,
+    libraryDependencies ++= Seq(
+      "io.swagger" % "swagger-annotations" % "1.6.5",
+      "com.squareup.okhttp3" % "okhttp" % "4.10.0",
+      "com.squareup.okhttp3" % "logging-interceptor" % "4.10.0",
+      "com.google.code.gson" % "gson" % "2.9.1",
+      "org.apache.commons" % "commons-lang3" % "3.12.0",
+      "javax.ws.rs" % "jsr311-api" % "1.1.1",
+      "javax.ws.rs" % "javax.ws.rs-api" % "2.1.1",
+      "org.openapitools" % "jackson-databind-nullable" % "0.2.6",
+      "io.gsonfire" % "gson-fire" % "1.8.5" % "compile",
+      "jakarta.annotation" % "jakarta.annotation-api" % "1.3.5" % "compile",
+      "com.google.code.findbugs" % "jsr305" % "3.0.2" % "compile",
+      "jakarta.annotation" % "jakarta.annotation-api" % "1.3.5" % "compile",
+      "org.junit.jupiter" % "junit-jupiter-api" % "5.9.1" % "test",
+      "com.novocode" % "junit-interface" % "0.10" % "test",
+      "org.mockito" % "mockito-core" % "3.12.4" % "test"
+    )
+  )

samples/client/others/java/okhttp-gson-oneOf/docs/DefaultApi.md

@@ -0,0 +1,68 @@
+# DefaultApi
+
+All URIs are relative to *http://localhost*
+
+| Method | HTTP request | Description |
+|------------- | ------------- | -------------|
+| [**myExamplePost**](DefaultApi.md#myExamplePost) | **POST** /myExample |  |
+
+
+<a id="myExamplePost"></a>
+# **myExamplePost**
+> myExamplePost(myExamplePostRequest)
+
+
+
+### 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.DefaultApi;
+
+public class Example {
+  public static void main(String[] args) {
+    ApiClient defaultClient = Configuration.getDefaultApiClient();
+    defaultClient.setBasePath("http://localhost");
+
+    DefaultApi apiInstance = new DefaultApi(defaultClient);
+    MyExamplePostRequest myExamplePostRequest = new MyExamplePostRequest(); // MyExamplePostRequest | 
+    try {
+      apiInstance.myExamplePost(myExamplePostRequest);
+    } catch (ApiException e) {
+      System.err.println("Exception when calling DefaultApi#myExamplePost");
+      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 |
+|------------- | ------------- | ------------- | -------------|
+| **myExamplePostRequest** | [**MyExamplePostRequest**](MyExamplePostRequest.md)|  | [optional] |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/json
+ - **Accept**: Not defined
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | OK |  -  |
+

samples/client/others/java/okhttp-gson-oneOf/docs/MyExamplePostRequest.md

@@ -0,0 +1,12 @@
+
+
+# MyExamplePostRequest
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+
+
+

samples/client/others/java/okhttp-gson-oneOf/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-petstore-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/others/java/okhttp-gson-oneOf/gradle.properties

@@ -0,0 +1,6 @@
+# This file is automatically generated by OpenAPI Generator (https://github.com/openAPITools/openapi-generator).
+# To include other gradle properties as part of the code generation process, please use the `gradleProperties` option.
+#
+# Gradle properties reference: https://docs.gradle.org/current/userguide/build_environment.html#sec:gradle_configuration_properties
+# For example, uncomment below to build for Android
+#target = android

samples/client/others/java/okhttp-gson-oneOf/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

samples/client/others/java/okhttp-gson-oneOf/gradlew

@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original 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 POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='-Dfile.encoding=UTF-8 "-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | 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" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

samples/client/others/java/okhttp-gson-oneOf/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=-Dfile.encoding=UTF-8 "-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/others/java/okhttp-gson-oneOf/pom.xml

@@ -0,0 +1,344 @@
+<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>openapi-java-client</artifactId>
+    <packaging>jar</packaging>
+    <name>openapi-java-client</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>http://unlicense.org</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>3.1.0</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>2.22.2</version>
+                <configuration>
+                    <systemProperties>
+                        <property>
+                            <name>loggerPath</name>
+                            <value>conf/log4j.properties</value>
+                        </property>
+                    </systemProperties>
+                    <argLine>-Xms512m -Xmx1500m</argLine>
+                    <parallel>methods</parallel>
+                    <threadCount>10</threadCount>
+                </configuration>
+                <dependencies>
+                    <!--Custom provider and engine for Junit 5 to surefire-->
+                    <dependency>
+                        <groupId>org.junit.jupiter</groupId>
+                        <artifactId>junit-jupiter-engine</artifactId>
+                        <version>${junit-version}</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
+            <plugin>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>3.3.0</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${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>3.3.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>test-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>build-helper-maven-plugin</artifactId>
+                <version>3.3.0</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-javadoc-plugin</artifactId>
+                <version>3.4.1</version>
+                <executions>
+                    <execution>
+                        <id>attach-javadocs</id>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <doclint>none</doclint>
+                    <tags>
+                        <tag>
+                            <name>http.response.details</name>
+                            <placement>a</placement>
+                            <head>Http Response Details:</head>
+                        </tag>
+                    </tags>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-source-plugin</artifactId>
+                <version>3.2.1</version>
+                <executions>
+                    <execution>
+                        <id>attach-sources</id>
+                        <goals>
+                            <goal>jar-no-fork</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <!-- Use spotless plugin to automatically format code, remove unused import, etc
+                 To apply changes directly to the file, run `mvn spotless:apply`
+                 Ref: https://github.com/diffplug/spotless/tree/main/plugin-maven
+            -->
+            <plugin>
+              <groupId>com.diffplug.spotless</groupId>
+              <artifactId>spotless-maven-plugin</artifactId>
+              <version>${spotless.version}</version>
+              <configuration>
+                <formats>
+                  <!-- you can define as many formats as you want, each is independent -->
+                  <format>
+                    <!-- define the files to apply to -->
+                    <includes>
+                      <include>.gitignore</include>
+                    </includes>
+                    <!-- define the steps to apply to those files -->
+                    <trimTrailingWhitespace/>
+                    <endWithNewline/>
+                    <indent>
+                      <spaces>true</spaces> <!-- or <tabs>true</tabs> -->
+                      <spacesPerTab>4</spacesPerTab> <!-- optional, default is 4 -->
+                    </indent>
+                  </format>
+                </formats>
+                <!-- define a language-specific format -->
+                <java>
+                  <!-- no need to specify files, inferred automatically, but you can if you want -->
+
+                  <!-- apply a specific flavor of google-java-format and reflow long strings -->
+                  <googleJavaFormat>
+                    <version>1.8</version>
+                    <style>AOSP</style>
+                    <reflowLongStrings>true</reflowLongStrings>
+                  </googleJavaFormat>
+
+                  <removeUnusedImports/>
+                  <importOrder/>
+
+                </java>
+              </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>sign-artifacts</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-gpg-plugin</artifactId>
+                        <version>3.0.1</version>
+                        <executions>
+                            <execution>
+                                <id>sign-artifacts</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>sign</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <dependencies>
+        <!-- @Nullable annotation -->
+        <dependency>
+            <groupId>com.google.code.findbugs</groupId>
+            <artifactId>jsr305</artifactId>
+            <version>3.0.2</version>
+        </dependency>
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>okhttp</artifactId>
+            <version>${okhttp-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.squareup.okhttp3</groupId>
+            <artifactId>logging-interceptor</artifactId>
+            <version>${okhttp-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>${gson-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.gsonfire</groupId>
+            <artifactId>gson-fire</artifactId>
+            <version>${gson-fire-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>jakarta.annotation</groupId>
+            <artifactId>jakarta.annotation-api</artifactId>
+            <version>${jakarta-annotation-version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openapitools</groupId>
+            <artifactId>jackson-databind-nullable</artifactId>
+            <version>${jackson-databind-nullable-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>jsr311-api</artifactId>
+            <version>${jsr311-api-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>javax.ws.rs-api</artifactId>
+            <version>${javax.ws.rs-api-version}</version>
+        </dependency>
+        <!-- test dependencies -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>${junit-version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit-platform-runner.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <properties>
+        <java.version>1.8</java.version>
+        <maven.compiler.source>${java.version}</maven.compiler.source>
+        <maven.compiler.target>${java.version}</maven.compiler.target>
+        <gson-fire-version>1.8.5</gson-fire-version>
+        <okhttp-version>4.11.0</okhttp-version>
+        <gson-version>2.10.1</gson-version>
+        <commons-lang3-version>3.13.0</commons-lang3-version>
+        <jackson-databind-nullable-version>0.2.6</jackson-databind-nullable-version>
+        <jakarta-annotation-version>1.3.5</jakarta-annotation-version>
+        <junit-version>5.10.0</junit-version>
+        <junit-platform-runner.version>1.10.0</junit-platform-runner.version>
+        <javax.ws.rs-api-version>2.1.1</javax.ws.rs-api-version>
+        <jsr311-api-version>1.1.1</jsr311-api-version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <spotless.version>2.27.2</spotless.version>
+    </properties>
+</project>

samples/client/others/java/okhttp-gson-oneOf/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "openapi-java-client"

samples/client/others/java/okhttp-gson-oneOf/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/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiCallback.java

@@ -0,0 +1,62 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.io.IOException;
+
+import java.util.Map;
+import java.util.List;
+
+/**
+ * Callback for asynchronous API call.
+ *
+ * @param <T> The return type
+ */
+public interface ApiCallback<T> {
+    /**
+     * This is called when the API call fails.
+     *
+     * @param e The exception causing the failure
+     * @param statusCode Status code of the response if available, otherwise it would be 0
+     * @param responseHeaders Headers of the response if available, otherwise it would be null
+     */
+    void onFailure(ApiException e, int statusCode, Map<String, List<String>> responseHeaders);
+
+    /**
+     * This is called when the API call succeeded.
+     *
+     * @param result The result deserialized from response
+     * @param statusCode Status code of the response
+     * @param responseHeaders Headers of the response
+     */
+    void onSuccess(T result, int statusCode, Map<String, List<String>> responseHeaders);
+
+    /**
+     * This is called when the API upload processing.
+     *
+     * @param bytesWritten bytes Written
+     * @param contentLength content length of request body
+     * @param done write end
+     */
+    void onUploadProgress(long bytesWritten, long contentLength, boolean done);
+
+    /**
+     * This is called when the API download processing.
+     *
+     * @param bytesRead bytes Read
+     * @param contentLength content length of the response
+     * @param done Read end
+     */
+    void onDownloadProgress(long bytesRead, long contentLength, boolean done);
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiException.java

@@ -0,0 +1,165 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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;
+
+
+/**
+ * <p>ApiException class.</p>
+ */
+@SuppressWarnings("serial")
+@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;
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     */
+    public ApiException() {}
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param throwable a {@link java.lang.Throwable} object
+     */
+    public ApiException(Throwable throwable) {
+        super(throwable);
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param message the error message
+     */
+    public ApiException(String message) {
+        super(message);
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param message the error message
+     * @param throwable a {@link java.lang.Throwable} object
+     * @param code HTTP status code
+     * @param responseHeaders a {@link java.util.Map} of HTTP response headers
+     * @param responseBody the response body
+     */
+    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;
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param message the error message
+     * @param code HTTP status code
+     * @param responseHeaders a {@link java.util.Map} of HTTP response headers
+     * @param responseBody the response body
+     */
+    public ApiException(String message, int code, Map<String, List<String>> responseHeaders, String responseBody) {
+        this(message, (Throwable) null, code, responseHeaders, responseBody);
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param message the error message
+     * @param throwable a {@link java.lang.Throwable} object
+     * @param code HTTP status code
+     * @param responseHeaders a {@link java.util.Map} of HTTP response headers
+     */
+    public ApiException(String message, Throwable throwable, int code, Map<String, List<String>> responseHeaders) {
+        this(message, throwable, code, responseHeaders, null);
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param code HTTP status code
+     * @param responseHeaders a {@link java.util.Map} of HTTP response headers
+     * @param responseBody the response body
+     */
+    public ApiException(int code, Map<String, List<String>> responseHeaders, String responseBody) {
+        this("Response Code: " + code + " Response Body: " + responseBody, (Throwable) null, code, responseHeaders, responseBody);
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param code HTTP status code
+     * @param message a {@link java.lang.String} object
+     */
+    public ApiException(int code, String message) {
+        super(message);
+        this.code = code;
+    }
+
+    /**
+     * <p>Constructor for ApiException.</p>
+     *
+     * @param code HTTP status code
+     * @param message the error message
+     * @param responseHeaders a {@link java.util.Map} of HTTP response headers
+     * @param responseBody the response body
+     */
+    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;
+    }
+
+    /**
+     * Get the exception message including HTTP response data.
+     *
+     * @return The exception message
+     */
+    public String getMessage() {
+        return String.format("Message: %s%nHTTP response code: %s%nHTTP response body: %s%nHTTP response headers: %s",
+                super.getMessage(), this.getCode(), this.getResponseBody(), this.getResponseHeaders());
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiResponse.java

@@ -0,0 +1,76 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.List;
+import java.util.Map;
+
+/**
+ * API response returned by API call.
+ */
+public class ApiResponse<T> {
+    final private int statusCode;
+    final private Map<String, List<String>> headers;
+    final private T data;
+
+    /**
+     * <p>Constructor for ApiResponse.</p>
+     *
+     * @param statusCode The status code of HTTP response
+     * @param headers The headers of HTTP response
+     */
+    public ApiResponse(int statusCode, Map<String, List<String>> headers) {
+        this(statusCode, headers, null);
+    }
+
+    /**
+     * <p>Constructor for ApiResponse.</p>
+     *
+     * @param statusCode The status code of HTTP response
+     * @param headers The headers of HTTP response
+     * @param data The object deserialized from response bod
+     */
+    public ApiResponse(int statusCode, Map<String, List<String>> headers, T data) {
+        this.statusCode = statusCode;
+        this.headers = headers;
+        this.data = data;
+    }
+
+    /**
+     * <p>Get the <code>status code</code>.</p>
+     *
+     * @return the status code
+     */
+    public int getStatusCode() {
+        return statusCode;
+    }
+
+    /**
+     * <p>Get the <code>headers</code>.</p>
+     *
+     * @return a {@link java.util.Map} of headers 
+     */
+    public Map<String, List<String>> getHeaders() {
+        return headers;
+    }
+
+    /**
+     * <p>Get the <code>data</code>.</p>
+     *
+     * @return the data
+     */
+    public T getData() {
+        return data;
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/Configuration.java

@@ -0,0 +1,41 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 {
+    public static final String VERSION = "1.0.0";
+
+    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/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/GzipRequestInterceptor.java

@@ -0,0 +1,85 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 okhttp3.*;
+import okio.Buffer;
+import okio.BufferedSink;
+import okio.GzipSink;
+import okio.Okio;
+
+import java.io.IOException;
+
+/**
+ * Encodes request bodies using gzip.
+ *
+ * Taken from https://github.com/square/okhttp/issues/350
+ */
+class GzipRequestInterceptor implements Interceptor {
+    @Override
+    public Response intercept(Chain chain) throws IOException {
+        Request originalRequest = chain.request();
+        if (originalRequest.body() == null || originalRequest.header("Content-Encoding") != null) {
+            return chain.proceed(originalRequest);
+        }
+
+        Request compressedRequest = originalRequest.newBuilder()
+                                                   .header("Content-Encoding", "gzip")
+                                                   .method(originalRequest.method(), forceContentLength(gzip(originalRequest.body())))
+                                                   .build();
+        return chain.proceed(compressedRequest);
+    }
+
+    private RequestBody forceContentLength(final RequestBody requestBody) throws IOException {
+        final Buffer buffer = new Buffer();
+        requestBody.writeTo(buffer);
+        return new RequestBody() {
+            @Override
+            public MediaType contentType() {
+                return requestBody.contentType();
+            }
+
+            @Override
+            public long contentLength() {
+                return buffer.size();
+            }
+
+            @Override
+            public void writeTo(BufferedSink sink) throws IOException {
+                sink.write(buffer.snapshot());
+            }
+        };
+    }
+
+    private RequestBody gzip(final RequestBody body) {
+        return new RequestBody() {
+            @Override
+            public MediaType contentType() {
+                return body.contentType();
+            }
+
+            @Override
+            public long contentLength() {
+                return -1; // We don't know the compressed length in advance!
+            }
+
+            @Override
+            public void writeTo(BufferedSink sink) throws IOException {
+                BufferedSink gzipSink = Okio.buffer(new GzipSink(sink));
+                body.writeTo(gzipSink);
+                gzipSink.close();
+            }
+        };
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/JSON.java

@@ -0,0 +1,401 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonParseException;
+import com.google.gson.TypeAdapter;
+import com.google.gson.internal.bind.util.ISO8601Utils;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import com.google.gson.JsonElement;
+import io.gsonfire.GsonFireBuilder;
+import io.gsonfire.TypeSelector;
+
+import okio.ByteString;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.lang.reflect.Type;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.ParsePosition;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.Date;
+import java.util.Locale;
+import java.util.Map;
+import java.util.HashMap;
+
+/*
+ * A JSON utility class
+ *
+ * NOTE: in the future, this class may be converted to static, which may break
+ *       backward-compatibility
+ */
+public class JSON {
+    private static Gson gson;
+    private static boolean isLenientOnJson = false;
+    private static DateTypeAdapter dateTypeAdapter = new DateTypeAdapter();
+    private static SqlDateTypeAdapter sqlDateTypeAdapter = new SqlDateTypeAdapter();
+    private static OffsetDateTimeTypeAdapter offsetDateTimeTypeAdapter = new OffsetDateTimeTypeAdapter();
+    private static LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
+    private static ByteArrayAdapter byteArrayAdapter = new ByteArrayAdapter();
+
+    @SuppressWarnings("unchecked")
+    public static GsonBuilder createGson() {
+        GsonFireBuilder fireBuilder = new GsonFireBuilder()
+        ;
+        GsonBuilder builder = fireBuilder.createGsonBuilder();
+        return builder;
+    }
+
+    private static String getDiscriminatorValue(JsonElement readElement, String discriminatorField) {
+        JsonElement element = readElement.getAsJsonObject().get(discriminatorField);
+        if (null == element) {
+            throw new IllegalArgumentException("missing discriminator field: <" + discriminatorField + ">");
+        }
+        return element.getAsString();
+    }
+
+    /**
+     * Returns the Java class that implements the OpenAPI schema for the specified discriminator value.
+     *
+     * @param classByDiscriminatorValue The map of discriminator values to Java classes.
+     * @param discriminatorValue The value of the OpenAPI discriminator in the input data.
+     * @return The Java class that implements the OpenAPI schema
+     */
+    private static Class getClassByDiscriminator(Map classByDiscriminatorValue, String discriminatorValue) {
+        Class clazz = (Class) classByDiscriminatorValue.get(discriminatorValue);
+        if (null == clazz) {
+            throw new IllegalArgumentException("cannot determine model class of name: <" + discriminatorValue + ">");
+        }
+        return clazz;
+    }
+
+    {
+        GsonBuilder gsonBuilder = createGson();
+        gsonBuilder.registerTypeAdapter(Date.class, dateTypeAdapter);
+        gsonBuilder.registerTypeAdapter(java.sql.Date.class, sqlDateTypeAdapter);
+        gsonBuilder.registerTypeAdapter(OffsetDateTime.class, offsetDateTimeTypeAdapter);
+        gsonBuilder.registerTypeAdapter(LocalDate.class, localDateTypeAdapter);
+        gsonBuilder.registerTypeAdapter(byte[].class, byteArrayAdapter);
+        gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.MyExamplePostRequest.CustomTypeAdapterFactory());
+        gson = gsonBuilder.create();
+    }
+
+    /**
+     * Get Gson.
+     *
+     * @return Gson
+     */
+    public static Gson getGson() {
+        return gson;
+    }
+
+    /**
+     * Set Gson.
+     *
+     * @param gson Gson
+     */
+    public static void setGson(Gson gson) {
+        JSON.gson = gson;
+    }
+
+    public static void setLenientOnJson(boolean lenientOnJson) {
+        isLenientOnJson = lenientOnJson;
+    }
+
+    /**
+     * Serialize the given Java object into JSON string.
+     *
+     * @param obj Object
+     * @return String representation of the JSON
+     */
+    public static String serialize(Object obj) {
+        return gson.toJson(obj);
+    }
+
+    /**
+     * Deserialize the given JSON string to Java object.
+     *
+     * @param <T>        Type
+     * @param body       The JSON string
+     * @param returnType The type to deserialize into
+     * @return The deserialized Java object
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T deserialize(String body, Type returnType) {
+        try {
+            if (isLenientOnJson) {
+                JsonReader jsonReader = new JsonReader(new StringReader(body));
+                // see https://google-gson.googlecode.com/svn/trunk/gson/docs/javadocs/com/google/gson/stream/JsonReader.html#setLenient(boolean)
+                jsonReader.setLenient(true);
+                return gson.fromJson(jsonReader, returnType);
+            } else {
+                return gson.fromJson(body, returnType);
+            }
+        } catch (JsonParseException e) {
+            // Fallback processing when failed to parse JSON form response body:
+            // return the response body string directly for the String return type;
+            if (returnType.equals(String.class)) {
+                return (T) body;
+            } else {
+                throw (e);
+            }
+        }
+    }
+
+    /**
+     * Gson TypeAdapter for Byte Array type
+     */
+    public static class ByteArrayAdapter extends TypeAdapter<byte[]> {
+
+        @Override
+        public void write(JsonWriter out, byte[] value) throws IOException {
+            if (value == null) {
+                out.nullValue();
+            } else {
+                out.value(ByteString.of(value).base64());
+            }
+        }
+
+        @Override
+        public byte[] read(JsonReader in) throws IOException {
+            switch (in.peek()) {
+                case NULL:
+                    in.nextNull();
+                    return null;
+                default:
+                    String bytesAsBase64 = in.nextString();
+                    ByteString byteString = ByteString.decodeBase64(bytesAsBase64);
+                    return byteString.toByteArray();
+            }
+        }
+    }
+
+    /**
+     * Gson TypeAdapter for JSR310 OffsetDateTime type
+     */
+    public static class OffsetDateTimeTypeAdapter extends TypeAdapter<OffsetDateTime> {
+
+        private DateTimeFormatter formatter;
+
+        public OffsetDateTimeTypeAdapter() {
+            this(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
+        }
+
+        public OffsetDateTimeTypeAdapter(DateTimeFormatter formatter) {
+            this.formatter = formatter;
+        }
+
+        public void setFormat(DateTimeFormatter dateFormat) {
+            this.formatter = dateFormat;
+        }
+
+        @Override
+        public void write(JsonWriter out, OffsetDateTime date) throws IOException {
+            if (date == null) {
+                out.nullValue();
+            } else {
+                out.value(formatter.format(date));
+            }
+        }
+
+        @Override
+        public OffsetDateTime read(JsonReader in) throws IOException {
+            switch (in.peek()) {
+                case NULL:
+                    in.nextNull();
+                    return null;
+                default:
+                    String date = in.nextString();
+                    if (date.endsWith("+0000")) {
+                        date = date.substring(0, date.length()-5) + "Z";
+                    }
+                    return OffsetDateTime.parse(date, formatter);
+            }
+        }
+    }
+
+    /**
+     * Gson TypeAdapter for JSR310 LocalDate type
+     */
+    public static class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {
+
+        private DateTimeFormatter formatter;
+
+        public LocalDateTypeAdapter() {
+            this(DateTimeFormatter.ISO_LOCAL_DATE);
+        }
+
+        public LocalDateTypeAdapter(DateTimeFormatter formatter) {
+            this.formatter = formatter;
+        }
+
+        public void setFormat(DateTimeFormatter dateFormat) {
+            this.formatter = dateFormat;
+        }
+
+        @Override
+        public void write(JsonWriter out, LocalDate date) throws IOException {
+            if (date == null) {
+                out.nullValue();
+            } else {
+                out.value(formatter.format(date));
+            }
+        }
+
+        @Override
+        public LocalDate read(JsonReader in) throws IOException {
+            switch (in.peek()) {
+                case NULL:
+                    in.nextNull();
+                    return null;
+                default:
+                    String date = in.nextString();
+                    return LocalDate.parse(date, formatter);
+            }
+        }
+    }
+
+    public static void setOffsetDateTimeFormat(DateTimeFormatter dateFormat) {
+        offsetDateTimeTypeAdapter.setFormat(dateFormat);
+    }
+
+    public static void setLocalDateFormat(DateTimeFormatter dateFormat) {
+        localDateTypeAdapter.setFormat(dateFormat);
+    }
+
+    /**
+     * Gson TypeAdapter for java.sql.Date type
+     * If the dateFormat is null, a simple "yyyy-MM-dd" format will be used
+     * (more efficient than SimpleDateFormat).
+     */
+    public static class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {
+
+        private DateFormat dateFormat;
+
+        public SqlDateTypeAdapter() {}
+
+        public SqlDateTypeAdapter(DateFormat dateFormat) {
+            this.dateFormat = dateFormat;
+        }
+
+        public void setFormat(DateFormat dateFormat) {
+            this.dateFormat = dateFormat;
+        }
+
+        @Override
+        public void write(JsonWriter out, java.sql.Date date) throws IOException {
+            if (date == null) {
+                out.nullValue();
+            } else {
+                String value;
+                if (dateFormat != null) {
+                    value = dateFormat.format(date);
+                } else {
+                    value = date.toString();
+                }
+                out.value(value);
+            }
+        }
+
+        @Override
+        public java.sql.Date read(JsonReader in) throws IOException {
+            switch (in.peek()) {
+                case NULL:
+                    in.nextNull();
+                    return null;
+                default:
+                    String date = in.nextString();
+                    try {
+                        if (dateFormat != null) {
+                            return new java.sql.Date(dateFormat.parse(date).getTime());
+                        }
+                        return new java.sql.Date(ISO8601Utils.parse(date, new ParsePosition(0)).getTime());
+                    } catch (ParseException e) {
+                        throw new JsonParseException(e);
+                    }
+            }
+        }
+    }
+
+    /**
+     * Gson TypeAdapter for java.util.Date type
+     * If the dateFormat is null, ISO8601Utils will be used.
+     */
+    public static class DateTypeAdapter extends TypeAdapter<Date> {
+
+        private DateFormat dateFormat;
+
+        public DateTypeAdapter() {}
+
+        public DateTypeAdapter(DateFormat dateFormat) {
+            this.dateFormat = dateFormat;
+        }
+
+        public void setFormat(DateFormat dateFormat) {
+            this.dateFormat = dateFormat;
+        }
+
+        @Override
+        public void write(JsonWriter out, Date date) throws IOException {
+            if (date == null) {
+                out.nullValue();
+            } else {
+                String value;
+                if (dateFormat != null) {
+                    value = dateFormat.format(date);
+                } else {
+                    value = ISO8601Utils.format(date, true);
+                }
+                out.value(value);
+            }
+        }
+
+        @Override
+        public Date read(JsonReader in) throws IOException {
+            try {
+                switch (in.peek()) {
+                    case NULL:
+                        in.nextNull();
+                        return null;
+                    default:
+                        String date = in.nextString();
+                        try {
+                            if (dateFormat != null) {
+                                return dateFormat.parse(date);
+                            }
+                            return ISO8601Utils.parse(date, new ParsePosition(0));
+                        } catch (ParseException e) {
+                            throw new JsonParseException(e);
+                        }
+                }
+            } catch (IllegalArgumentException e) {
+                throw new JsonParseException(e);
+            }
+        }
+    }
+
+    public static void setDateFormat(DateFormat dateFormat) {
+        dateTypeAdapter.setFormat(dateFormat);
+    }
+
+    public static void setSqlDateFormat(DateFormat dateFormat) {
+        sqlDateTypeAdapter.setFormat(dateFormat);
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/Pair.java

@@ -0,0 +1,57 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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;
+        }
+
+        return true;
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ProgressRequestBody.java

@@ -0,0 +1,73 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 okhttp3.MediaType;
+import okhttp3.RequestBody;
+
+import java.io.IOException;
+
+import okio.Buffer;
+import okio.BufferedSink;
+import okio.ForwardingSink;
+import okio.Okio;
+import okio.Sink;
+
+public class ProgressRequestBody extends RequestBody {
+
+    private final RequestBody requestBody;
+
+    private final ApiCallback callback;
+
+    public ProgressRequestBody(RequestBody requestBody, ApiCallback callback) {
+        this.requestBody = requestBody;
+        this.callback = callback;
+    }
+
+    @Override
+    public MediaType contentType() {
+        return requestBody.contentType();
+    }
+
+    @Override
+    public long contentLength() throws IOException {
+        return requestBody.contentLength();
+    }
+
+    @Override
+    public void writeTo(BufferedSink sink) throws IOException {
+        BufferedSink bufferedSink = Okio.buffer(sink(sink));
+        requestBody.writeTo(bufferedSink);
+        bufferedSink.flush();
+    }
+
+    private Sink sink(Sink sink) {
+        return new ForwardingSink(sink) {
+
+            long bytesWritten = 0L;
+            long contentLength = 0L;
+
+            @Override
+            public void write(Buffer source, long byteCount) throws IOException {
+                super.write(source, byteCount);
+                if (contentLength == 0) {
+                    contentLength = contentLength();
+                }
+
+                bytesWritten += byteCount;
+                callback.onUploadProgress(bytesWritten, contentLength, bytesWritten == contentLength);
+            }
+        };
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ProgressResponseBody.java

@@ -0,0 +1,70 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 okhttp3.MediaType;
+import okhttp3.ResponseBody;
+
+import java.io.IOException;
+
+import okio.Buffer;
+import okio.BufferedSource;
+import okio.ForwardingSource;
+import okio.Okio;
+import okio.Source;
+
+public class ProgressResponseBody extends ResponseBody {
+
+    private final ResponseBody responseBody;
+    private final ApiCallback callback;
+    private BufferedSource bufferedSource;
+
+    public ProgressResponseBody(ResponseBody responseBody, ApiCallback callback) {
+        this.responseBody = responseBody;
+        this.callback = callback;
+    }
+
+    @Override
+    public MediaType contentType() {
+        return responseBody.contentType();
+    }
+
+    @Override
+    public long contentLength() {
+        return responseBody.contentLength();
+    }
+
+    @Override
+    public BufferedSource source() {
+        if (bufferedSource == null) {
+            bufferedSource = Okio.buffer(source(responseBody.source()));
+        }
+        return bufferedSource;
+    }
+
+    private Source source(Source source) {
+        return new ForwardingSource(source) {
+            long totalBytesRead = 0L;
+
+            @Override
+            public long read(Buffer sink, long byteCount) throws IOException {
+                long bytesRead = super.read(sink, byteCount);
+                // read() returns the number of bytes read, or -1 if this source is exhausted.
+                totalBytesRead += bytesRead != -1 ? bytesRead : 0;
+                callback.onDownloadProgress(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
+                return bytesRead;
+            }
+        };
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/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 description 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 IllegalArgumentException("The variable " + name + " in the server URL has invalid value " + value + ".");
+                }
+            }
+            url = url.replace("{" + name + "}", value);
+        }
+        return url;
+    }
+
+    /**
+     * Format URL template using default server variables.
+     *
+     * @return Formatted URL.
+     */
+    public String URL() {
+        return URL(null);
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/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/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/StringUtil.java

@@ -0,0 +1,83 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/api/DefaultApi.java

@@ -0,0 +1,188 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 org.openapitools.client.ApiCallback;
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.ApiResponse;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.Pair;
+import org.openapitools.client.ProgressRequestBody;
+import org.openapitools.client.ProgressResponseBody;
+
+import com.google.gson.reflect.TypeToken;
+
+import java.io.IOException;
+
+
+import org.openapitools.client.model.MyExamplePostRequest;
+
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class DefaultApi {
+    private ApiClient localVarApiClient;
+    private int localHostIndex;
+    private String localCustomBaseUrl;
+
+    public DefaultApi() {
+        this(Configuration.getDefaultApiClient());
+    }
+
+    public DefaultApi(ApiClient apiClient) {
+        this.localVarApiClient = apiClient;
+    }
+
+    public ApiClient getApiClient() {
+        return localVarApiClient;
+    }
+
+    public void setApiClient(ApiClient apiClient) {
+        this.localVarApiClient = apiClient;
+    }
+
+    public int getHostIndex() {
+        return localHostIndex;
+    }
+
+    public void setHostIndex(int hostIndex) {
+        this.localHostIndex = hostIndex;
+    }
+
+    public String getCustomBaseUrl() {
+        return localCustomBaseUrl;
+    }
+
+    public void setCustomBaseUrl(String customBaseUrl) {
+        this.localCustomBaseUrl = customBaseUrl;
+    }
+
+    /**
+     * Build call for myExamplePost
+     * @param myExamplePostRequest  (optional)
+     * @param _callback Callback for upload/download progress
+     * @return Call to execute
+     * @throws ApiException If fail to serialize the request body object
+     * @http.response.details
+     <table summary="Response Details" border="1">
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td> OK </td><td>  -  </td></tr>
+     </table>
+     */
+    public okhttp3.Call myExamplePostCall(MyExamplePostRequest myExamplePostRequest, final ApiCallback _callback) throws ApiException {
+        String basePath = null;
+        // Operation Servers
+        String[] localBasePaths = new String[] {  };
+
+        // Determine Base Path to Use
+        if (localCustomBaseUrl != null){
+            basePath = localCustomBaseUrl;
+        } else if ( localBasePaths.length > 0 ) {
+            basePath = localBasePaths[localHostIndex];
+        } else {
+            basePath = null;
+        }
+
+        Object localVarPostBody = myExamplePostRequest;
+
+        // create path and map variables
+        String localVarPath = "/myExample";
+
+        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 = localVarApiClient.selectHeaderAccept(localVarAccepts);
+        if (localVarAccept != null) {
+            localVarHeaderParams.put("Accept", localVarAccept);
+        }
+
+        final String[] localVarContentTypes = {
+            "application/json"
+        };
+        final String localVarContentType = localVarApiClient.selectHeaderContentType(localVarContentTypes);
+        if (localVarContentType != null) {
+            localVarHeaderParams.put("Content-Type", localVarContentType);
+        }
+
+        String[] localVarAuthNames = new String[] {  };
+        return localVarApiClient.buildCall(basePath, localVarPath, "POST", localVarQueryParams, localVarCollectionQueryParams, localVarPostBody, localVarHeaderParams, localVarCookieParams, localVarFormParams, localVarAuthNames, _callback);
+    }
+
+    @SuppressWarnings("rawtypes")
+    private okhttp3.Call myExamplePostValidateBeforeCall(MyExamplePostRequest myExamplePostRequest, final ApiCallback _callback) throws ApiException {
+        return myExamplePostCall(myExamplePostRequest, _callback);
+
+    }
+
+    /**
+     * 
+     * 
+     * @param myExamplePostRequest  (optional)
+     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+     * @http.response.details
+     <table summary="Response Details" border="1">
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td> OK </td><td>  -  </td></tr>
+     </table>
+     */
+    public void myExamplePost(MyExamplePostRequest myExamplePostRequest) throws ApiException {
+        myExamplePostWithHttpInfo(myExamplePostRequest);
+    }
+
+    /**
+     * 
+     * 
+     * @param myExamplePostRequest  (optional)
+     * @return ApiResponse&lt;Void&gt;
+     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
+     * @http.response.details
+     <table summary="Response Details" border="1">
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td> OK </td><td>  -  </td></tr>
+     </table>
+     */
+    public ApiResponse<Void> myExamplePostWithHttpInfo(MyExamplePostRequest myExamplePostRequest) throws ApiException {
+        okhttp3.Call localVarCall = myExamplePostValidateBeforeCall(myExamplePostRequest, null);
+        return localVarApiClient.execute(localVarCall);
+    }
+
+    /**
+     *  (asynchronously)
+     * 
+     * @param myExamplePostRequest  (optional)
+     * @param _callback The callback to be executed when the API call finishes
+     * @return The request call
+     * @throws ApiException If fail to process the API call, e.g. serializing the request body object
+     * @http.response.details
+     <table summary="Response Details" border="1">
+        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
+        <tr><td> 200 </td><td> OK </td><td>  -  </td></tr>
+     </table>
+     */
+    public okhttp3.Call myExamplePostAsync(MyExamplePostRequest myExamplePostRequest, final ApiCallback<Void> _callback) throws ApiException {
+
+        okhttp3.Call localVarCall = myExamplePostValidateBeforeCall(myExamplePostRequest, _callback);
+        localVarApiClient.executeAsync(localVarCall, _callback);
+        return localVarCall;
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/auth/ApiKeyAuth.java

@@ -0,0 +1,80 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.ApiException;
+import org.openapitools.client.Pair;
+
+import java.net.URI;
+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,
+                           String payload, String method, URI uri) throws ApiException {
+    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/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/auth/Authentication.java

@@ -0,0 +1,36 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 org.openapitools.client.ApiException;
+
+import java.net.URI;
+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
+     * @param payload HTTP request body
+     * @param method HTTP method
+     * @param uri URI
+     * @throws ApiException if failed to update the parameters
+     */
+    void applyToParams(List<Pair> queryParams, Map<String, String> headerParams, Map<String, String> cookieParams, String payload, String method, URI uri) throws ApiException;
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/auth/HttpBasicAuth.java

@@ -0,0 +1,57 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 org.openapitools.client.ApiException;
+
+import okhttp3.Credentials;
+
+import java.net.URI;
+import java.util.Map;
+import java.util.List;
+
+import java.io.UnsupportedEncodingException;
+
+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,
+                              String payload, String method, URI uri) throws ApiException {
+        if (username == null && password == null) {
+            return;
+        }
+        headerParams.put("Authorization", Credentials.basic(
+            username == null ? "" : username,
+            password == null ? "" : password));
+    }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/auth/HttpBearerAuth.java

@@ -0,0 +1,63 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.ApiException;
+import org.openapitools.client.Pair;
+
+import java.net.URI;
+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,
+                            String payload, String method, URI uri) throws ApiException {
+    if (bearerToken == null) {
+      return;
+    }
+
+    headerParams.put("Authorization", (scheme != null ? upperCaseBearer(scheme) + " " : "") + bearerToken);
+  }
+
+  private static String upperCaseBearer(String scheme) {
+    return ("bearer".equalsIgnoreCase(scheme)) ? "Bearer" : scheme;
+  }
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/AbstractOpenApiSchema.java

@@ -0,0 +1,148 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.model;
+
+import org.openapitools.client.ApiException;
+import java.util.Objects;
+import java.lang.reflect.Type;
+import java.util.Map;
+
+//import com.fasterxml.jackson.annotation.JsonValue;
+
+/**
+ * Abstract class for oneOf,anyOf schemas defined in OpenAPI spec
+ */
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public abstract class AbstractOpenApiSchema {
+
+    // store the actual instance of the schema/object
+    private Object instance;
+
+    // is nullable
+    private Boolean isNullable;
+
+    // schema type (e.g. oneOf, anyOf)
+    private final String schemaType;
+
+    public AbstractOpenApiSchema(String schemaType, Boolean isNullable) {
+        this.schemaType = schemaType;
+        this.isNullable = isNullable;
+    }
+
+    /**
+     * Get the list of oneOf/anyOf composed schemas allowed to be stored in this object
+     *
+     * @return an instance of the actual schema/object
+     */
+    public abstract Map<String, Class<?>> getSchemas();
+
+    /**
+     * Get the actual instance
+     *
+     * @return an instance of the actual schema/object
+     */
+    //@JsonValue
+    public Object getActualInstance() {return instance;}
+
+    /**
+     * Set the actual instance
+     *
+     * @param instance the actual instance of the schema/object
+     */
+    public void setActualInstance(Object instance) {this.instance = instance;}
+
+    /**
+     * Get the instant recursively when the schemas defined in oneOf/anyof happen to be oneOf/anyOf schema as well
+     *
+     * @return an instance of the actual schema/object
+     */
+    public Object getActualInstanceRecursively() {
+        return getActualInstanceRecursively(this);
+    }
+
+    private Object getActualInstanceRecursively(AbstractOpenApiSchema object) {
+        if (object.getActualInstance() == null) {
+            return null;
+        } else if (object.getActualInstance() instanceof AbstractOpenApiSchema) {
+            return getActualInstanceRecursively((AbstractOpenApiSchema)object.getActualInstance());
+        } else {
+            return object.getActualInstance();
+        }
+    }
+
+    /**
+     * Get the schema type (e.g. anyOf, oneOf)
+     *
+     * @return the schema type
+     */
+    public String getSchemaType() {
+        return schemaType;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("class ").append(getClass()).append(" {\n");
+        sb.append("    instance: ").append(toIndentedString(instance)).append("\n");
+        sb.append("    isNullable: ").append(toIndentedString(isNullable)).append("\n");
+        sb.append("    schemaType: ").append(toIndentedString(schemaType)).append("\n");
+        sb.append("}");
+        return sb.toString();
+    }
+
+    /**
+     * Convert the given object to string with each line indented by 4 spaces
+     * (except the first line).
+     */
+    private String toIndentedString(Object o) {
+        if (o == null) {
+            return "null";
+        }
+        return o.toString().replace("\n", "\n    ");
+    }
+
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        AbstractOpenApiSchema a = (AbstractOpenApiSchema) o;
+        return Objects.equals(this.instance, a.instance) &&
+            Objects.equals(this.isNullable, a.isNullable) &&
+            Objects.equals(this.schemaType, a.schemaType);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(instance, isNullable, schemaType);
+    }
+
+    /**
+     * Is nullable
+     *
+     * @return true if it's nullable
+     */
+    public Boolean isNullable() {
+        if (Boolean.TRUE.equals(isNullable)) {
+            return Boolean.TRUE;
+        } else {
+            return Boolean.FALSE;
+        }
+    }
+
+
+
+}

samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/model/MyExamplePostRequest.java

@@ -0,0 +1,225 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.model;
+
+import java.util.Objects;
+
+
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonParseException;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.annotations.JsonAdapter;
+import com.google.gson.annotations.SerializedName;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonParseException;
+
+import org.openapitools.client.JSON;
+
+@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen")
+public class MyExamplePostRequest extends AbstractOpenApiSchema {
+    private static final Logger log = Logger.getLogger(MyExamplePostRequest.class.getName());
+
+    public static class CustomTypeAdapterFactory implements TypeAdapterFactory {
+        @SuppressWarnings("unchecked")
+        @Override
+        public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+            if (!MyExamplePostRequest.class.isAssignableFrom(type.getRawType())) {
+                return null; // this class only serializes 'MyExamplePostRequest' and its subtypes
+            }
+            final TypeAdapter<JsonElement> elementAdapter = gson.getAdapter(JsonElement.class);
+            final TypeAdapter<String> adapterString = gson.getDelegateAdapter(this, TypeToken.get(String.class));
+
+            return (TypeAdapter<T>) new TypeAdapter<MyExamplePostRequest>() {
+                @Override
+                public void write(JsonWriter out, MyExamplePostRequest value) throws IOException {
+                    if (value == null || value.getActualInstance() == null) {
+                        elementAdapter.write(out, null);
+                        return;
+                    }
+
+                    // check if the actual instance is of the type `String`
+                    if (value.getActualInstance() instanceof String) {
+                      JsonPrimitive primitive = adapterString.toJsonTree((String)value.getActualInstance()).getAsJsonPrimitive();
+                      elementAdapter.write(out, primitive);
+                      return;
+                    }
+                    throw new IOException("Failed to serialize as the type doesn't match oneOf schemas: String");
+                }
+
+                @Override
+                public MyExamplePostRequest read(JsonReader in) throws IOException {
+                    Object deserialized = null;
+                    JsonElement jsonElement = elementAdapter.read(in);
+
+                    int match = 0;
+                    ArrayList<String> errorMessages = new ArrayList<>();
+                    TypeAdapter actualAdapter = elementAdapter;
+
+                    // deserialize String
+                    try {
+                      // validate the JSON object to see if any exception is thrown
+                      if(!jsonElement.getAsJsonPrimitive().isString()) {
+                        throw new IllegalArgumentException(String.format("Expected json element to be of type String in the JSON string but got `%s`", jsonElement.toString()));
+                      }
+                      actualAdapter = adapterString;
+                      match++;
+                      log.log(Level.FINER, "Input data matches schema 'String'");
+                    } catch (Exception e) {
+                      // deserialization failed, continue
+                      errorMessages.add(String.format("Deserialization for String failed with `%s`.", e.getMessage()));
+                      log.log(Level.FINER, "Input data does not match schema 'String'", e);
+                    }
+
+                    if (match == 1) {
+                        MyExamplePostRequest ret = new MyExamplePostRequest();
+                        ret.setActualInstance(actualAdapter.fromJsonTree(jsonElement));
+                        return ret;
+                    }
+
+                    throw new IOException(String.format("Failed deserialization for MyExamplePostRequest: %d classes match result, expected 1. Detailed failure message for oneOf schemas: %s. JSON: %s", match, errorMessages, jsonElement.toString()));
+                }
+            }.nullSafe();
+        }
+    }
+
+    // store a list of schema names defined in oneOf
+    public static final Map<String, Class<?>> schemas = new HashMap<String, Class<?>>();
+
+    public MyExamplePostRequest() {
+        super("oneOf", Boolean.FALSE);
+    }
+
+    public MyExamplePostRequest(String o) {
+        super("oneOf", Boolean.FALSE);
+        setActualInstance(o);
+    }
+
+    static {
+        schemas.put("String", String.class);
+    }
+
+    @Override
+    public Map<String, Class<?>> getSchemas() {
+        return MyExamplePostRequest.schemas;
+    }
+
+    /**
+     * Set the instance that matches the oneOf child schema, check
+     * the instance parameter is valid against the oneOf child schemas:
+     * String
+     *
+     * It could be an instance of the 'oneOf' schemas.
+     */
+    @Override
+    public void setActualInstance(Object instance) {
+        if (instance instanceof String) {
+            super.setActualInstance(instance);
+            return;
+        }
+
+        throw new RuntimeException("Invalid instance type. Must be String");
+    }
+
+    /**
+     * Get the actual instance, which can be the following:
+     * String
+     *
+     * @return The actual instance (String)
+     */
+    @Override
+    public Object getActualInstance() {
+        return super.getActualInstance();
+    }
+
+    /**
+     * Get the actual instance of `String`. If the actual instance is not `String`,
+     * the ClassCastException will be thrown.
+     *
+     * @return The actual instance of `String`
+     * @throws ClassCastException if the instance is not `String`
+     */
+    public String getString() throws ClassCastException {
+        return (String)super.getActualInstance();
+    }
+
+ /**
+  * Validates the JSON Element and throws an exception if issues found
+  *
+  * @param jsonElement JSON Element
+  * @throws IOException if the JSON Element is invalid with respect to MyExamplePostRequest
+  */
+  public static void validateJsonElement(JsonElement jsonElement) throws IOException {
+    // validate oneOf schemas one by one
+    int validCount = 0;
+    ArrayList<String> errorMessages = new ArrayList<>();
+    // validate the json string with String
+    try {
+      if(!jsonElement.getAsJsonPrimitive().isString()) {
+        throw new IllegalArgumentException(String.format("Expected json element to be of type String in the JSON string but got `%s`", jsonElement.toString()));
+      }
+      validCount++;
+    } catch (Exception e) {
+      errorMessages.add(String.format("Deserialization for String failed with `%s`.", e.getMessage()));
+      // continue to the next one
+    }
+    if (validCount != 1) {
+      throw new IOException(String.format("The JSON string is invalid for MyExamplePostRequest with oneOf schemas: String. %d class(es) match the result, expected 1. Detailed failure message for oneOf schemas: %s. JSON: %s", validCount, errorMessages, jsonElement.toString()));
+    }
+  }
+
+ /**
+  * Create an instance of MyExamplePostRequest given an JSON string
+  *
+  * @param jsonString JSON string
+  * @return An instance of MyExamplePostRequest
+  * @throws IOException if the JSON string is invalid with respect to MyExamplePostRequest
+  */
+  public static MyExamplePostRequest fromJson(String jsonString) throws IOException {
+    return JSON.getGson().fromJson(jsonString, MyExamplePostRequest.class);
+  }
+
+ /**
+  * Convert an instance of MyExamplePostRequest to an JSON string
+  *
+  * @return JSON string
+  */
+  public String toJson() {
+    return JSON.getGson().toJson(this);
+  }
+}
+

samples/client/others/java/okhttp-gson-oneOf/src/test/java/org/openapitools/client/api/DefaultApiTest.java

@@ -0,0 +1,44 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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 org.openapitools.client.ApiException;
+import org.openapitools.client.model.MyExamplePostRequest;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * API tests for DefaultApi
+ */
+@Disabled
+public class DefaultApiTest {
+
+    private final DefaultApi api = new DefaultApi();
+
+    /**
+     * @throws ApiException if the Api call fails
+     */
+    @Test
+    public void myExamplePostTest() throws ApiException {
+        MyExamplePostRequest myExamplePostRequest = null;
+        api.myExamplePost(myExamplePostRequest);
+        // TODO: test validations
+    }
+
+}

samples/client/others/java/okhttp-gson-oneOf/src/test/java/org/openapitools/client/model/MyExamplePostRequestTest.java

@@ -0,0 +1,33 @@
+/*
+ * oneOf two primitives
+ * oneOf with two entries of type string, see https://github.com/OpenAPITools/openapi-generator/issues/10450
+ *
+ * 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.model;
+
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Model tests for MyExamplePostRequest
+ */
+public class MyExamplePostRequestTest {
+    private final MyExamplePostRequest model = new MyExamplePostRequest();
+
+    /**
+     * Model tests for MyExamplePostRequest
+     */
+    @Test
+    public void testMyExamplePostRequest() {
+        // TODO: test MyExamplePostRequest
+    }
+
+}