[BUG] jaxrs-spec generator missing import in api class for subclass used in path parameter

Description

I have a derived/subclass model generated using allOf, which is used in a path param in an API. The jaxrs-spec generator in v6.0.0 is generating the API class without an import for the derived class. It contains an import for the superclass instead. It will not compile.

In this case the subclass contains no members of its own, but the problem also occurs if it does have additional members.

openapi-generator version

6.0.0. Works in 5.4.0.

OpenAPI declaration file content

openapi: "3.0.3"
info:
  version: 1.0.0
  title: Bug demo
servers:
  - url: http://localhost:8080/
paths:
  /test/{derived}:
    post:
      operationId: generatorBug
      parameters:
        - name: derived
          in: path
          style: simple
          explode: true
          required: true
          schema:
            $ref: "#/components/schemas/Derived"
      responses:
        '200':
          description: Success
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"

components:
  schemas:
    Error:
      type: object
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string

    Base:
      type: object
      discriminator:
        propertyName: discriminator
      properties:
        name:
          type: string
        discriminator:
          type: string
      required:
        - name
        - discriminator
      additionalProperties: false

    Derived:
      allOf:
        - $ref: "#/components/schemas/Base"

Generation Details

Command line:

docker run --rm -v ${PWD}:/local openapitools/openapi-generator-cli:v6.0.0 generate -i local/openapi.yaml -g jaxrs-spec -o /local/out/java

Steps to reproduce

• Run the above command on the given yaml.
• Observe the generated TestApi.java and see that it contains an import for Base but not Derived. Derived is correctly generated as a path param for the generatorBug operation, but without the proper import, will not compile.

The generated api class:

package org.openapitools.api;

import org.openapitools.model.Base;
import org.openapitools.model.Error;

import javax.ws.rs.*;
import javax.ws.rs.core.Response;

import io.swagger.annotations.*;

import java.io.InputStream;
import java.util.Map;
import java.util.List;
import javax.validation.constraints.*;
import javax.validation.Valid;

@Path("/test/{derived}")
@Api(description = "the test API")
@javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaJAXRSSpecServerCodegen", date = "2022-06-28T13:56:54.632290Z[Etc/UTC]")
public class TestApi {

    @POST
    @Produces({ "application/json" })
    @ApiOperation(value = "", notes = "", response = Void.class, tags={  })
    @ApiResponses(value = { 
        @ApiResponse(code = 200, message = "Success", response = Void.class),
        @ApiResponse(code = 200, message = "unexpected error", response = Error.class)
    })
    public Response generatorBug(@PathParam("derived") Derived derived) {
        return Response.ok().entity("magic!").build();
    }
}

Related issues/PRs

Found none.

Suggest a fix

The generator should generate the class with the proper import, as in v 5.4.0.

Start with the supplied OpenAPI declaration and reproduce the issue using the jaxrs-spec generator command for v6.0.0. Compare the generated TestApi.java with the v5.4.0 output, focusing on imports for the Derived path parameter and the generated Base and Derived models. Done means the generated API imports Derived rather than only Base and compiles.