Added HttpClient5 flavour to Java OpenFeign client generator.

Author: Knuf

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"

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 -->