OpenAPI 以嵌套类型返回 null

Question

I have SpringBoot app with Mybatis and Rest API made by OpenAPI Here is my swagger file:

 /api/v1/getdata:
    get:
      summary: ttttttt
      tags:
        - "API"
      description: ttttttt
      operationId: getdata
      parameters:
        - name: sap
          in: header
          required: true
          description: ttttttt
          schema:
            type: string
        - name: created
          in: header
          required: true
          description: ttttttt
          schema:
            type: string
      responses:
        "200":
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MyResponse'
        "404":
          description: Not Found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MyResponse'

components:
  schemas:    
    MyResponse:
        description: ttttttt
        type: object
        properties:
        code:
            description: ttttttt
            type: string
        body:
            $ref: '#/components/schemas/MyMetaData'
    
    MyMetaData:
      description: ttttttt
      type: object
      properties:
        id:
          description: id
          type: string
        somedata:
          description: ttttttt
          $ref: '#/components/schemas/MyData'
    
    MyData:
      description: ttttttt
      type: object
      properties:
        id:
          description: id
          type: string
        group:
          description: ttttttt
          type: string

Here is my controller code:

@Override
public ResponseEntity<MyResponse> getdata(String sap, String created) {
    MyResponse myResponse = new MyResponse();
    try {
        OffsetDateTime date = OffsetDateTime.parse(created, DateTimeFormatter.ISO_OFFSET_DATE_TIME);
        Optional<MyMetaData> optionalMetaData = Optional.ofNullable(this.MyMetaDataMapper.getdata(sap, date));
        if (optionalMetaData.isPresent()) {
            myResponse.setBody(optionalMetaData.get());
            myResponse.setCode("OK");
        }
        return ResponseEntity.status(HttpStatus.OK).body(myResponse);
    } catch (Exception e) {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(myResponse);
    }
}

Here is generated model:

@javax.annotation.Generated(value = "io.swagger.codegen.v3.generators.java.SpringCodegen", date = "2022-03-01T12:24:46.999519+03:00")
public class MyMetaData   {
  @JsonProperty("id")
  private String id = null;

  @JsonProperty("somedata")
  private MyData somedata = null;

  public MyMetaData id(String id) {
    this.id = id;
    return this;
  }

When I use time MyData like this, as a result i get null:

  somedata:
      description: ttttttt
      $ref: '#/components/schemas/MyData'

When somedata is of type string, then I get some normal data from my database. What's the correct way to use object type here?

Answer 1

The OpenAPI swagger file that you have shared has $ref: '#/components/schemas/MyData ' but components and schema is missing in the paths of MyData.

As per Open API documentation it should be

components:
  schemas:
    User:    # Schema name
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 1          # Property example
        name:
          type: string
          example: New order  # Property example

For nested objects there is already a StackOverflow question which might help. Github issue .

You can try something similar

components:
  schemas:
    MyMetaData:
      type: object
      description: ttttttt
      properties:
        id:
          description: id
          type: string
        somedata:
          description: ttttttt
          $ref: '#/components/schemas/MyData'
    MyData:
      type: object
      description: ttttttt
      properties:
        id:
          description: id
          type: string  

If you still face issue with OpenAPI swagger you can try SpringDoc . It supports OpenAPI 3+ and generates Swagger documentation easily. You can find a lot of examples over web.

Sample: Baeldung OpenAPI Dzone SpringDoc OpenApi