Add openapi.yaml file to Java clients (#5765)

* Add openapi.yaml file to Java client

* Move supporting template file to Java root

* Update petstore clients

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

@@ -293,6 +293,8 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         supportingFiles.add(new SupportingFile("ApiClient.mustache", invokerFolder, "ApiClient.java"));
         supportingFiles.add(new SupportingFile("ServerConfiguration.mustache", invokerFolder, "ServerConfiguration.java"));
         supportingFiles.add(new SupportingFile("ServerVariable.mustache", invokerFolder, "ServerVariable.java"));
+        supportingFiles.add(new SupportingFile("openapi.mustache", "api", "openapi.yaml"));
+
 
         if (!(RESTTEMPLATE.equals(getLibrary()) || REST_ASSURED.equals(getLibrary()) || NATIVE.equals(getLibrary()) || MICROPROFILE.equals(getLibrary()))) {
             supportingFiles.add(new SupportingFile("StringUtil.mustache", invokerFolder, "StringUtil.java"));
@@ -883,6 +885,12 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         return mime != null && JSON_VENDOR_MIME_PATTERN.matcher(mime).matches();
     }
 
+    @Override
+    public Map<String, Object> postProcessSupportingFileData(Map<String, Object> objs) {
+        generateYAMLSpecFile(objs);
+        return super.postProcessSupportingFileData(objs);
+    }
+
     @Override
     public String toApiVarName(String name) {
         String apiVarName = super.toApiVarName(name);

modules/openapi-generator/src/main/resources/Java/openapi.mustache

@@ -0,0 +1 @@
+{{{openapi-yaml}}}

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -267,7 +267,7 @@ public class JavaClientCodegenTest {
         generator.opts(clientOptInput).generate();
 
         Map<String, String> generatedFiles = generator.getFiles();
-        Assert.assertEquals(generatedFiles.size(), 36);
+        Assert.assertEquals(generatedFiles.size(), 37);
         TestUtils.ensureContainsFile(generatedFiles, output, ".gitignore");
         TestUtils.ensureContainsFile(generatedFiles, output, ".openapi-generator-ignore");
         TestUtils.ensureContainsFile(generatedFiles, output, ".openapi-generator/VERSION");
@@ -284,6 +284,7 @@ public class JavaClientCodegenTest {
         TestUtils.ensureContainsFile(generatedFiles, output, "pom.xml");
         TestUtils.ensureContainsFile(generatedFiles, output, "README.md");
         TestUtils.ensureContainsFile(generatedFiles, output, "settings.gradle");
+        TestUtils.ensureContainsFile(generatedFiles, output, "api/openapi.yaml");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/AndroidManifest.xml");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/java/xyz/abcdef/api/DefaultApi.java");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/java/xyz/abcdef/ApiCallback.java");
@@ -342,7 +343,7 @@ public class JavaClientCodegenTest {
         generator.opts(clientOptInput).generate();
 
         Map<String, String> generatedFiles = generator.getFiles();
-        Assert.assertEquals(generatedFiles.size(), 39);
+        Assert.assertEquals(generatedFiles.size(), 40);
         TestUtils.ensureContainsFile(generatedFiles, output, ".gitignore");
         TestUtils.ensureContainsFile(generatedFiles, output, ".openapi-generator-ignore");
         TestUtils.ensureContainsFile(generatedFiles, output, ".openapi-generator/VERSION");
@@ -360,6 +361,7 @@ public class JavaClientCodegenTest {
         TestUtils.ensureContainsFile(generatedFiles, output, "pom.xml");
         TestUtils.ensureContainsFile(generatedFiles, output, "README.md");
         TestUtils.ensureContainsFile(generatedFiles, output, "settings.gradle");
+        TestUtils.ensureContainsFile(generatedFiles, output, "api/openapi.yaml");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/AndroidManifest.xml");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/java/zz/yyyy/api/xxxx/PingApi.java");
         TestUtils.ensureContainsFile(generatedFiles, output, "src/main/java/zz/yyyy/invoker/xxxx/ApiCallback.java");
@@ -414,7 +416,7 @@ public class JavaClientCodegenTest {
         generator.opts(clientOptInput).generate();
 
         Map<String, String> generatedFiles = generator.getFiles();
-        Assert.assertEquals(generatedFiles.size(), 25);
+        Assert.assertEquals(generatedFiles.size(), 26);
         validateJavaSourceFiles(generatedFiles);
 
         String defaultApiFilename = new File(output, "src/main/java/xyz/abcdef/api/DefaultApi.java").getAbsolutePath().replace("\\", "/");