do not generate root resource or application file if generating interface

Author: rignicat

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

@@ -187,19 +187,22 @@ public void processOpts() {
         supportingFiles.clear(); // Don't need extra files provided by AbstractJAX-RS & Java Codegen
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md")
                 .doNotOverwrite());
-        supportingFiles.add(new SupportingFile("RestResourceRoot.mustache",
-                (sourceFolder + '/' + invokerPackage).replace(".", "/"), "RestResourceRoot.java")
-                .doNotOverwrite());
+
+        if (!interfaceOnly) {
+            supportingFiles.add(new SupportingFile("RestResourceRoot.mustache",
+                    (sourceFolder + '/' + invokerPackage).replace(".", "/"), "RestResourceRoot.java")
+                    .doNotOverwrite());
+
+            supportingFiles.add(new SupportingFile("RestApplication.mustache",
+                    (sourceFolder + '/' + invokerPackage).replace(".", "/"), "RestApplication.java")
+                    .doNotOverwrite());
+        }
 
         if (generatePom) {
             supportingFiles.add(new SupportingFile("pom.mustache", "", "pom.xml")
                     .doNotOverwrite());
         }
 
-        supportingFiles.add(new SupportingFile("RestApplication.mustache",
-                (sourceFolder + '/' + invokerPackage).replace(".", "/"), "RestApplication.java")
-                .doNotOverwrite());
-
         if (StringUtils.isNotEmpty(openApiSpecFileLocation)) {
             int index = openApiSpecFileLocation.lastIndexOf('/');
             String fileFolder;