Added HttpClient5 flavour to Java OpenFeign client generator. (#21007)

* Added HttpClient5 flavour to Java OpenFeign client generator.

* Converted templates intendation to spaces.

* Added the new sample folder to GH wf so that the CI can test the change.

* Added the missing auto-generated docs/samples files.

* Converted indentation to spaces also in the modified Java class.

Author: Knuf

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

@@ -74,6 +74,7 @@ jobs:
           - samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter
           - samples/client/petstore/java/apache-httpclient
           - samples/client/petstore/java/feign
+          - samples/client/petstore/java/feign-hc5
           - samples/client/petstore/java/feign-no-nullable
           - samples/client/petstore/java/okhttp-gson-awsv4signature
           - samples/openapi3/client/petstore/java/jersey2-java8-special-characters

bin/configs/java-feign-hc5.yaml

@@ -0,0 +1,9 @@
+generatorName: java
+outputDir: samples/client/petstore/java/feign-hc5
+library: feign-hc5
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/Java
+additionalProperties:
+  booleanGetterPrefix: is
+  artifactId: petstore-feign-hc5
+  hideGenerationTimestamp: "true"

docs/generators/java-microprofile.md

@@ -62,7 +62,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |implicitHeadersRegex|Skip header parameters that matches given regex in the generated API methods using @ApiImplicitParams annotation. Note: this parameter is ignored when implicitHeaders=true| |null|
 |invokerPackage|root package for generated code| |org.openapitools.client|
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
-|library|library template (sub-template) to use|<dl><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1</dd><dt>**jersey3**</dt><dd>HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if `useJakartaEe=true`). JSON processing: Jackson 2.17.1</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.1.18. JSON processing: Jackson 2.17.1</dd><dt>**restclient**</dt><dd>HTTP client: Spring RestClient 6.1.6. JSON processing: Jackson 2.17.1</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 4.7.6. JSON processing: Jackson 2.17.1</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.5.2. JSON processing: Jackson 2.17.1</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 2.2.0. JSON processing: Jackson 2.17.1</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured 5.3.2. JSON processing: Gson 2.10.1 or Jackson 2.17.1. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.17.1. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 2.0 (default, set desired version via `microprofileRestClientVersion=x.x.x`). JSON processing: JSON-B 1.0.2 or Jackson 2.17.1</dd><dt>**apache-httpclient**</dt><dd>HTTP client: Apache httpclient 5.2.1. JSON processing: Jackson 2.17.1</dd></dl>|okhttp-gson|
+|library|library template (sub-template) to use|<dl><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1</dd><dt>**jersey3**</dt><dd>HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**feign-hc5**</dt><dd>HTTP client: OpenFeign 13.2.1/HttpClient5 5.4.2. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if `useJakartaEe=true`). JSON processing: Jackson 2.17.1</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.1.18. JSON processing: Jackson 2.17.1</dd><dt>**restclient**</dt><dd>HTTP client: Spring RestClient 6.1.6. JSON processing: Jackson 2.17.1</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 4.7.6. JSON processing: Jackson 2.17.1</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.5.2. JSON processing: Jackson 2.17.1</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 2.2.0. JSON processing: Jackson 2.17.1</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured 5.3.2. JSON processing: Gson 2.10.1 or Jackson 2.17.1. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.17.1. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 2.0 (default, set desired version via `microprofileRestClientVersion=x.x.x`). JSON processing: JSON-B 1.0.2 or Jackson 2.17.1</dd><dt>**apache-httpclient**</dt><dd>HTTP client: Apache httpclient 5.2.1. JSON processing: Jackson 2.17.1</dd></dl>|okhttp-gson|
 |licenseName|The name of the license| |Unlicense|
 |licenseUrl|The URL of the license| |http://unlicense.org|
 |microprofileFramework|Framework for microprofile. Possible values &quot;kumuluzee&quot;| |null|

docs/generators/java.md

@@ -62,7 +62,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |implicitHeadersRegex|Skip header parameters that matches given regex in the generated API methods using @ApiImplicitParams annotation. Note: this parameter is ignored when implicitHeaders=true| |null|
 |invokerPackage|root package for generated code| |org.openapitools.client|
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
-|library|library template (sub-template) to use|<dl><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1</dd><dt>**jersey3**</dt><dd>HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if `useJakartaEe=true`). JSON processing: Jackson 2.17.1</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.1.18. JSON processing: Jackson 2.17.1</dd><dt>**restclient**</dt><dd>HTTP client: Spring RestClient 6.1.6. JSON processing: Jackson 2.17.1</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 4.7.6. JSON processing: Jackson 2.17.1</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.5.2. JSON processing: Jackson 2.17.1</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 2.2.0. JSON processing: Jackson 2.17.1</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured 5.3.2. JSON processing: Gson 2.10.1 or Jackson 2.17.1. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.17.1. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 2.0 (default, set desired version via `microprofileRestClientVersion=x.x.x`). JSON processing: JSON-B 1.0.2 or Jackson 2.17.1</dd><dt>**apache-httpclient**</dt><dd>HTTP client: Apache httpclient 5.2.1. JSON processing: Jackson 2.17.1</dd></dl>|okhttp-gson|
+|library|library template (sub-template) to use|<dl><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1</dd><dt>**jersey3**</dt><dd>HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**feign-hc5**</dt><dd>HTTP client: OpenFeign 13.2.1/HttpClient5 5.4.2. JSON processing: Jackson 2.17.1 or Gson 2.10.1</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if `useJakartaEe=true`). JSON processing: Jackson 2.17.1</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.1.18. JSON processing: Jackson 2.17.1</dd><dt>**restclient**</dt><dd>HTTP client: Spring RestClient 6.1.6. JSON processing: Jackson 2.17.1</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 4.7.6. JSON processing: Jackson 2.17.1</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.5.2. JSON processing: Jackson 2.17.1</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 2.2.0. JSON processing: Jackson 2.17.1</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured 5.3.2. JSON processing: Gson 2.10.1 or Jackson 2.17.1. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.17.1. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client 2.0 (default, set desired version via `microprofileRestClientVersion=x.x.x`). JSON processing: JSON-B 1.0.2 or Jackson 2.17.1</dd><dt>**apache-httpclient**</dt><dd>HTTP client: Apache httpclient 5.2.1. JSON processing: Jackson 2.17.1</dd></dl>|okhttp-gson|
 |licenseName|The name of the license| |Unlicense|
 |licenseUrl|The URL of the license| |http://unlicense.org|
 |microprofileFramework|Framework for microprofile. Possible values &quot;kumuluzee&quot;| |null|

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

@@ -78,6 +78,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
     public static final String ERROR_OBJECT_TYPE = "errorObjectType";
 
     public static final String FEIGN = "feign";
+    public static final String FEIGN_HC5 = "feign-hc5";
     public static final String GOOGLE_API_CLIENT = "google-api-client";
     public static final String JERSEY2 = "jersey2";
     public static final String JERSEY3 = "jersey3";
@@ -246,6 +247,7 @@ public JavaClientCodegen() {
         supportedLibraries.put(JERSEY2, "HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1");
         supportedLibraries.put(JERSEY3, "HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1");
         supportedLibraries.put(FEIGN, "HTTP client: OpenFeign 13.2.1. JSON processing: Jackson 2.17.1 or Gson 2.10.1");
+        supportedLibraries.put(FEIGN_HC5, "HTTP client: OpenFeign 13.2.1/HttpClient5 5.4.2. JSON processing: Jackson 2.17.1 or Gson 2.10.1");
         supportedLibraries.put(OKHTTP_GSON, "[DEFAULT] HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.");
         supportedLibraries.put(RETROFIT_2, "HTTP client: OkHttp 4.11.0. JSON processing: Gson 2.10.1 (Retrofit 2.5.0) or Jackson 2.17.1. Enable the RxJava adapter using '-DuseRxJava[2/3]=true'. (RxJava 1.x or 2.x or 3.x)");
         supportedLibraries.put(RESTTEMPLATE, "HTTP client: Spring RestTemplate 5.3.33 (6.1.5 if `useJakartaEe=true`). JSON processing: Jackson 2.17.1");
@@ -325,7 +327,7 @@ public void processOpts() {
 
         // determine and cache client library type once
         final boolean libApache = isLibrary(APACHE);
-        final boolean libFeign = isLibrary(FEIGN);
+        final boolean libFeign = isLibrary(FEIGN) || isLibrary(FEIGN_HC5);
         final boolean libGoogleApiClient = isLibrary(GOOGLE_API_CLIENT);
         final boolean libJersey2 = isLibrary(JERSEY2);
         final boolean libJersey3 = isLibrary(JERSEY3);
@@ -745,6 +747,14 @@ public void processOpts() {
                 additionalProperties.remove(SERIALIZATION_LIBRARY_JSONB);
                 break;
         }
+        
+        if (isLibrary(FEIGN)) {
+            additionalProperties.put("feign-okhttp", "true");
+        } else if (isLibrary(FEIGN_HC5)) {
+            additionalProperties.put("feign-hc5", "true");
+            setTemplateDir(FEIGN);
+            setLibrary(FEIGN);
+        }
 
         // authentication related files
         // has OAuth defined
@@ -825,7 +835,7 @@ public int compare(CodegenParameter one, CodegenParameter another) {
         }
 
         // camelize path variables for Feign client
-        if (isLibrary(FEIGN)) {
+        if (isLibrary(FEIGN) || isLibrary(FEIGN_HC5)) {
             OperationMap operations = objs.getOperations();
             List<CodegenOperation> operationList = operations.getOperation();
             Pattern methodPattern = Pattern.compile("^(.*):([^:]*)$");

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

@@ -9,7 +9,12 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 {{#jackson}}
+{{#feign-okhttp}}
 import feign.okhttp.OkHttpClient;
+{{/feign-okhttp}}
+{{#feign-hc5}}
+import feign.hc5.ApacheHttp5Client;
+{{/feign-hc5}}
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -71,7 +76,12 @@ public class ApiClient {
     {{#jackson}}
     objectMapper = createObjectMapper();
     feignBuilder = Feign.builder()
+                {{#feign-okhttp}}
                 .client(new OkHttpClient())
+                {{/feign-okhttp}}
+                {{#feign-hc5}}
+                .client(new ApacheHttp5Client())
+                {{/feign-hc5}}
                 .encoder(new FormEncoder(new JacksonEncoder(objectMapper)))
                 .decoder(new ApiResponseDecoder(objectMapper))
                 {{#hasOAuthMethods}}

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

@@ -127,7 +127,12 @@ dependencies {
     implementation "io.github.openfeign:feign-jackson:$feign_version"
     {{/jackson}}
     implementation "io.github.openfeign:feign-slf4j:$feign_version"
+    {{#feign-okhttp}}
     implementation "io.github.openfeign:feign-okhttp:$feign_version"
+    {{/feign-okhttp}}
+    {{#feign-hc5}}
+    implementation "io.github.openfeign:feign-hc5:$feign_version"
+    {{/feign-hc5}}
     implementation "io.github.openfeign.form:feign-form:$feign_form_version"
     {{#jackson}}
     {{#joda}}

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

@@ -17,7 +17,12 @@ lazy val root = (project in file(".")).
 {{/jackson}}
       "io.github.openfeign" % "feign-slf4j" % "13.5" % "compile",
       "io.github.openfeign.form" % "feign-form" % "3.8.0" % "compile",
+{{#feign-okhttp}}      
       "io.github.openfeign" % "feign-okhttp" % "13.5" % "compile",
+{{/feign-okhttp}}
+{{#feign-hc5}}
+         "io.github.openfeign" % "feign-hc5" % "13.5" % "compile",
+{{/feign-hc5}}
 {{#jackson}}
       "com.fasterxml.jackson.core" % "jackson-core" % "2.17.1" % "compile",
       "com.fasterxml.jackson.core" % "jackson-annotations" % "2.17.1" % "compile",

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

@@ -265,11 +265,20 @@
             <artifactId>feign-form</artifactId>
             <version>${feign-form-version}</version>
         </dependency>
+        {{#feign-okhttp}}
         <dependency>
             <groupId>io.github.openfeign</groupId>
             <artifactId>feign-okhttp</artifactId>
             <version>${feign-version}</version>
         </dependency>
+        {{/feign-okhttp}}
+        {{#feign-hc5}}
+        <dependency>
+            <groupId>io.github.openfeign</groupId>
+            <artifactId>feign-hc5</artifactId>
+            <version>${feign-version}</version>
+        </dependency>
+        {{/feign-hc5}}        
 
         {{#jackson}}
         <!-- JSON processing: jackson -->

samples/client/petstore/java/feign-hc5/.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 OpenAPI Petstore
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 17, 21 ]
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up JDK
+      uses: actions/setup-java@v4
+      with:
+        java-version: ${{ matrix.java }}
+        distribution: 'temurin'
+        cache: maven
+    - name: Build with Maven
+      run: mvn -B package --no-transfer-progress --file pom.xml