[JAVA][jaxrs] codegen with tags uses wrong @Path values

Start in JavaJerseyServerCodegen.addOperationToGroup() and compare the useTags=true fallback to DefaultCodegen with the useTags=false path handling. Regenerate the supplied YAML using the shown CLI command and verify that tagged Api classes retain the operation paths in @Path annotations, with matching @PathParam values.

Description

When creating jaxrs server stubs with useTags=true the Api classes have a wrong value for the @Path annotation. They contain the tag value (camel case) but not the path defined in the YAML file. When I omit useTags=true, then the @Path annotation contains the correct value but the Api class names are automatically generated (in not useful in my case).

Swagger-codegen version

2.3.1

Swagger declaration file

swagger: "2.0"
info:
  description: "Test REST API"
  version: "1.0.0"
  title: "Test"
host: "localhost"
basePath: "/v1"
schemes:
- "https"

tags:
- name: "document"

paths:
  /{userId}/documents:
    parameters:
    - name: "userId"
      in: "path"
      required: true
      type: "integer"
      format: "int64"

    get:
      tags:
      - "document"
      operationId: "getDocumentList"
      produces:
      - "application/json"
      responses:
        200:
          schema:
            type: "array"
            items:
              $ref: "#/definitions/DocumentListItem"

    post:
      tags:
        - "document"
      operationId: "createDocument"
      consumes:
      - "application/json"
      produces:
      - "application/json"
      parameters:
      - in: "body"
        name: "document"
        required: true
        schema:
          $ref: "#/definitions/Document"
      responses:
        200:
          schema:
            $ref: "#/definitions/Document"

  /{userId}/documents/{documentId}:
    parameters:
    - name: "userId"
      in: "path"
      required: true
      type: "integer"
      format: "int64"
    - name: "documentId"
      in: "path"
      required: true
      type: "string"

    get:
      tags:
        - "document"
      operationId: "getDocument"
      produces:
      - "application/json"
      responses:
        200:
          schema:
            $ref: "#/definitions/Document"
            
    put:
      tags:
        - "document"
      operationId: "updateDocument"
      consumes:
      - "application/json"
      produces:
      - "application/json"
      parameters:
      - in: "body"
        name: "document"
        required: true
        schema:
          $ref: "#/definitions/Document"
      responses:
        200:
          schema:
            $ref: "#/definitions/Document"
            
    delete:
      tags:
        - "document"
      operationId: "deleteDocument"
      produces:
      - "application/json"
      responses:
        204
      

definitions:

  DocumentListItem:
    type: "object"
    properties:
      id:
        type: "string"
      name:
        type: "string"

  Document:
    type: "object"
    properties:
      id:
        type: "string"
      name:
        type: "string"

Configuration file

{
	"java8": true,
	"dateLibrary": "java8",
	"useTags": true
}

Command line used for generation

java -jar swagger-codegen-cli-2.3.1.jar generate -l jaxrs -i test-api.yaml -c test-config.json

Generated Api class

@Path("/Document")
public class DocumentApi  {

    @POST
    public Response createDocument(@PathParam("userId") Long userId, Document document, ) {
        ...
    }

    @DELETE
    public Response deleteDocument(@PathParam("userId") Long userId, @PathParam("documentId") String documentId) {
        ...
    }

    @GET
    public Response getDocument(@PathParam("userId") Long userId, @PathParam("documentId") String documentId) {
        ...
    }

    @GET
    public Response getDocumentList(@PathParam("userId") Long userId) {
        ...
    }

    @PUT
    public Response updateDocument(@PathParam("userId") Long userId, @PathParam("documentId") String documentId, Document document) {
        ...
    }
}

Code shortened for readability. Only have a look at @Path and @PathParam.

As you can see, the class has the @Path annotation value "/Document" instead of "/{userId}/documents". The methods itself have no @Path annotation at all. The @PathParam annotations for userId and documentId are never defined within a @Path annotation. This is not valid with JaxRS.

Suggest a fix/enhancement

In JavaJerseyServerCodegen.addOperationToGroup() the code falls back to DefaultCodegen.addOperationToGroup() when useTags=true. And there the paths of the operations are not correctly handled.

    public void addOperationToGroup(String tag, String resourcePath, Operation operation, CodegenOperation co, Map<String, List<CodegenOperation>> operations) {
        if (useTags) {
            super.addOperationToGroup(tag, resourcePath, operation, co, operations);
        } else  {
            ...
        }
    }

Probably there should be a dedicated implementation instead of falling back to DefaultCodegen. The correct code might be nearly identical to the case when useTags=false but the name for the Api class have to match the tag name.