[JAVA] discriminator.mapping is not supported (in generated model)

Created by: 0v1se

Description

spec: https://swagger.io/docs/specification/data-models/inheritance-and-polymorphism/ mapping can be specified in discriminator:

discriminator:
  propertyName: petType
  mapping:
    dogggg: '#/components/schemas/Dog'
    catttt: '#/components/schemas/Cat'

Currently it's not taken in account when generating model (it's not for Java, may be for every other language too)

openapi-generator version

3.1.0-SNAPSHOT

OpenAPI declaration file content or url

openapi: "3.0.0"
info:
  version: 1.0.0
  title: Swagger Petstore
  license:
    name: MIT
servers:
  - url: http://petstore.swagger.io/v1
paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      tags:
        - pets
      parameters:
        - name: limit
          in: query
          description: How many items to return at one time (max 100)
          required: false
          schema:
            type: integer
            format: int32
      responses:
        '200':
          description: A paged array of pets
          headers:
            x-next:
              description: A link to the next page of responses
              schema:
                type: string
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
    post:
      summary: Create a pet
      operationId: createPets
      tags:
        - pets
      responses:
        '201':
          description: Null response
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
  /pets/{petId}:
    get:
      summary: Info for a specific pet
      operationId: showPetById
      tags:
        - pets
      parameters:
        - name: petId
          in: path
          required: true
          description: The id of the pet to retrieve
          schema:
            type: string
      responses:
        '200':
          description: Expected response to a valid request
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pets"
        default:
          description: unexpected error
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Error"
components:
  schemas:
    Pet:
      type: object
      discriminator:
        propertyName: petType
        mapping:
          dogggg: '#/components/schemas/Dog'
          catttt: '#/components/schemas/Cat'
      properties:
        name:
          type: string
        petType:
          type: string
      required:
      - name
      - petType
    Cat:
      description: A representation of a cat
      allOf:
      - $ref: '#/components/schemas/Pet'
      - type: object
        properties:
          huntingSkill:
            type: string
            description: The measured skill for hunting
            enum:
            - clueless
            - lazy
            - adventurous
            - aggressive
        required:
        - huntingSkill
    Dog:
      description: A representation of a dog
      allOf:
      - $ref: '#/components/schemas/Pet'
      - type: object
        properties:
          packSize:
            type: integer
            format: int32
            description: the size of the pack the dog is from
            default: 0
            minimum: 0
        required:
        - packSize
    Pets:
      type: array
      items:
        $ref: "#/components/schemas/Pet"
    Error:
      required:
        - code
        - message
      properties:
        code:
          type: integer
          format: int32
        message:
          type: string

Command line used for generation

java -jar ... generate -i api.yaml -g java --library resttemplate

Steps to reproduce

Generate model Here is what's generated in Pet.java:

@JsonSubTypes({
  @JsonSubTypes.Type(value = Cat.class, name = "Cat"),
  @JsonSubTypes.Type(value = Dog.class, name = "Dog"),
})

Related issues/PRs

Suggest a fix/enhancement

Should generate model like this:

@JsonSubTypes({
  @JsonSubTypes.Type(value = Cat.class, name = "catttt"),
  @JsonSubTypes.Type(value = Dog.class, name = "dogggg"),
})