set retrofit as a java library

Fix #1247
Fix #1248

Author: cbornet

README.md

@@ -265,6 +265,7 @@ CONFIG OPTIONS
 	    <default> - HTTP client: Jersey client 1.18. JSON processing: Jackson 2.4.2
 	    jersey2 - HTTP client: Jersey client 2.6
 	    okhttp-gson - HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1
+	    retrofit - HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1 (Retrofit 1.9.0)
 ```
 
 Your config file for java can look like

bin/all-petstore.sh

@@ -26,6 +26,7 @@ cd $APP_DIR
 ./bin/java-petstore.sh
 ./bin/java-petstore-jersey2.sh
 ./bin/java-petstore-okhttp-gson.sh
+./bin/java-petstore-retrofit.sh
 ./bin/jaxrs-petstore-server.sh
 ./bin/nodejs-petstore-server.sh
 ./bin/objc-petstore.sh
@@ -34,7 +35,6 @@ cd $APP_DIR
 ./bin/python-petstore.sh
 ./bin/python3-petstore.sh
 ./bin/qt5-petstore.sh
-./bin/retrofit-petstore.sh
 ./bin/ruby-petstore.sh
 ./bin/scala-async-petstore.sh
 ./bin/scala-petstore.sh

bin/java-petstore-retrofit.json

@@ -0,0 +1,4 @@
+{
+    "library": "retrofit",
+    "artifactId": "swagger-petstore-retrofit"
+}

bin/retrofit-petstore.sh renamed to bin/java-petstore-retrofit.sh

@@ -26,6 +26,6 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="$@ generate -t modules/swagger-codegen/src/main/resources/retrofit -i modules/swagger-codegen/src/test/resources/2_0/petstore.json -l retrofit -o samples/client/petstore/retrofit"
+ags="$@ generate -i modules/swagger-codegen/src/test/resources/2_0/petstore.json -l java -c bin/java-petstore-retrofit.json -o samples/client/petstore/java/retrofit"
 
 java $JAVA_OPTS -jar $executable $ags

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/JavaClientCodegen.java

@@ -5,6 +5,7 @@
 import io.swagger.codegen.CodegenConfig;
 import io.swagger.codegen.CodegenConstants;
 import io.swagger.codegen.CodegenModel;
+import io.swagger.codegen.CodegenOperation;
 import io.swagger.codegen.CodegenProperty;
 import io.swagger.codegen.CodegenType;
 import io.swagger.codegen.DefaultCodegen;
@@ -84,6 +85,7 @@ public JavaClientCodegen() {
         supportedLibraries.put("<default>", "HTTP client: Jersey client 1.18. JSON processing: Jackson 2.4.2");
         supportedLibraries.put("jersey2", "HTTP client: Jersey client 2.6");
         supportedLibraries.put("okhttp-gson", "HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1");
+        supportedLibraries.put("retrofit", "HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1 (Retrofit 1.9.0)");
         cliOptions.add(buildLibraryCliOption(supportedLibraries));
     }
 
@@ -155,12 +157,22 @@ public void processOpts() {
         final String invokerFolder = (sourceFolder + File.separator + invokerPackage).replace(".", File.separator);
         supportingFiles.add(new SupportingFile("pom.mustache", "", "pom.xml"));
         supportingFiles.add(new SupportingFile("ApiClient.mustache", invokerFolder, "ApiClient.java"));
-        supportingFiles.add(new SupportingFile("apiException.mustache", invokerFolder, "ApiException.java"));
-        supportingFiles.add(new SupportingFile("Configuration.mustache", invokerFolder, "Configuration.java"));
-        supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
-        supportingFiles.add(new SupportingFile("Pair.mustache", invokerFolder, "Pair.java"));
         supportingFiles.add(new SupportingFile("StringUtil.mustache", invokerFolder, "StringUtil.java"));
-
+        
+        final String authFolder = (sourceFolder + File.separator + invokerPackage + ".auth").replace(".", File.separator);
+        supportingFiles.add(new SupportingFile("auth/HttpBasicAuth.mustache", authFolder, "HttpBasicAuth.java"));
+        supportingFiles.add(new SupportingFile("auth/ApiKeyAuth.mustache", authFolder, "ApiKeyAuth.java"));
+        supportingFiles.add(new SupportingFile("auth/OAuth.mustache", authFolder, "OAuth.java"));
+        supportingFiles.add(new SupportingFile("auth/OAuthFlow.mustache", authFolder, "OAuthFlow.java"));
+
+        if (!"retrofit".equals(getLibrary())) {
+            supportingFiles.add(new SupportingFile("apiException.mustache", invokerFolder, "ApiException.java"));
+            supportingFiles.add(new SupportingFile("Configuration.mustache", invokerFolder, "Configuration.java"));
+            supportingFiles.add(new SupportingFile("JSON.mustache", invokerFolder, "JSON.java"));
+            supportingFiles.add(new SupportingFile("Pair.mustache", invokerFolder, "Pair.java"));
+            supportingFiles.add(new SupportingFile("auth/Authentication.mustache", authFolder, "Authentication.java"));
+        }
+        
         // library-specific files
         if ("okhttp-gson".equals(getLibrary())) {
             // the "okhttp-gson" library template requires "ApiCallback.mustache" for async call
@@ -169,16 +181,11 @@ public void processOpts() {
             supportingFiles.add(new SupportingFile("build.gradle.mustache", "", "build.gradle"));
             // "build.sbt" is for development with SBT
             supportingFiles.add(new SupportingFile("build.sbt.mustache", "", "build.sbt"));
-            // and does not require "TypeRef.mustache"
+        } else if ("retrofit".equals(getLibrary())) {
+            supportingFiles.add(new SupportingFile("auth/OAuthOkHttpClient.mustache", authFolder, "OAuthOkHttpClient.java"));
         } else {
             supportingFiles.add(new SupportingFile("TypeRef.mustache", invokerFolder, "TypeRef.java"));
         }
-
-        final String authFolder = (sourceFolder + File.separator + invokerPackage + ".auth").replace(".", File.separator);
-        supportingFiles.add(new SupportingFile("auth/Authentication.mustache", authFolder, "Authentication.java"));
-        supportingFiles.add(new SupportingFile("auth/HttpBasicAuth.mustache", authFolder, "HttpBasicAuth.java"));
-        supportingFiles.add(new SupportingFile("auth/ApiKeyAuth.mustache", authFolder, "ApiKeyAuth.java"));
-        supportingFiles.add(new SupportingFile("auth/OAuth.mustache", authFolder, "OAuth.java"));
     }
 
     private void sanitizeConfig() {
@@ -373,6 +380,29 @@ public Map<String, Object> postProcessModels(Map<String, Object> objs) {
         }
         return objs;
     }
+    
+    public Map<String, Object> postProcessOperations(Map<String, Object> objs) {
+        if("retrofit".equals(getLibrary())) {
+            Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
+            if (operations != null) {
+                List<CodegenOperation> ops = (List<CodegenOperation>) operations.get("operation");
+                for (CodegenOperation operation : ops) {
+                    if (operation.hasConsumes == Boolean.TRUE) {
+                        Map<String, String> firstType = operation.consumes.get(0);
+                        if (firstType != null) {
+                            if ("multipart/form-data".equals(firstType.get("mediaType"))) {
+                                operation.isMultipart = Boolean.TRUE;
+                            }
+                        }
+                    }
+                    if (operation.returnType == null) {
+                        operation.returnType = "Void";
+                    }
+                }
+            }
+        }
+        return objs;
+    }
 
     private CodegenModel reconcileInlineEnums(CodegenModel codegenModel, CodegenModel parentCodegenModel) {
         // This generator uses inline classes to define enums, which breaks when

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/RetrofitClientCodegen.java

@@ -1,5 +1,5 @@
 package {{invokerPackage}}.auth;
 
-public enum OauthFlow {
+public enum OAuthFlow {
     accessCode, implicit, password, application
 }