[BUG] [java] [maven] Swagger page does not contain api from java superclass

Description

I have a BaseController implementing general purpose api and concrete controllers extending it ( e.g.: AnswersController ).

public abstract class BaseController<V extends ViewModel>  {

  ...

  public ResponseEntity<List<V>> getAll() {
    return ...
  }
}

@RestController
public class AnswerController extends BaseController<AnswerDto> implements AnswersApi {

  // @Override
  // public ResponseEntity<List<AnswerDto>> getAll() {
  // return super.getAll();
  // }
}

AnswerController is implementing a interface generated by plugin. The interface contains all the general methods, as in example:

   @Operation(
        operationId = "getAll",
        summary = "GET -> retrieve all answers",
        responses = {
            @ApiResponse(responseCode = "200", description = "OK", content = {
                @Content(mediaType = "application/json", array = @ArraySchema(schema = @Schema(implementation = AnswerDto.class)))
            })
        }
    )
    @RequestMapping(
        method = RequestMethod.GET,
        value = "/answers",
        produces = { "application/json" }
    )
    default ResponseEntity<List<AnswerDto>> getAll(
        
    ) {
        getRequest().ifPresent(request -> {
            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
                    String exampleString = "[ { ... } ]";
                    ApiUtil.setExampleResponse(request, "application/json", exampleString);
                    break;
                }
            }
        });
        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);

    }

In order to have in swagger page AnswerController.getAll, I have to uncomment the method in the controller. The inherited method from BaseController is not used to create documentation of the swagger page. Am I missing something?

openapi-generator version

<openapi.generator.version>6.3.0</openapi.generator.version>

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: project
  description: description
  version: 1.0.0

paths:

  /answers:
    get:
      summary: "GET -> retrieve all answers"
      operationId: "getAll"
      responses:
        "200":
          description: "OK"
          content:
            'application/json':
              schema:
                type: "array"
                items:
                  $ref: "#/components/schemas/AnswerDto"

components:
  schemas:

    BaseDto:
      properties:
        id:
          type: "integer"
          format: "int64"


    AnswerDto:
      allOf:
        - $ref: "#/components/schemas/BaseDto"
      x-implements: ['package.ViewModel']
      properties:
        note:
          type: "string"
        fkSupplierSurvey:
          type: "integer"
          format: "int64"
        fkPossibleAnswer:
          type: "integer"
          format: "int64"

Generation Details

<plugin>
   <groupId>org.openapitools</groupId>
   <artifactId>openapi-generator-maven-plugin</artifactId>
   <version>${openapi.generator.version}</version>
   <executions>
      <execution>
         <goals>
            <goal>generate</goal>
         </goals>
         <configuration>
            <skipValidateSpec>true</skipValidateSpec> <!-- allow  multiple openations with same id -->
            <inputSpec>${openapi.spec}</inputSpec>
            <generatorName>spring</generatorName>
            <library>spring-boot</library>
            <output>${generated.source.directory}</output>
            <apiPackage>${openapi.api.package}</apiPackage>
            <modelPackage>${openapi.model.package}</modelPackage>
            <generateSupportingFiles>true</generateSupportingFiles>
            <configOptions>
               <sourceFolder>/</sourceFolder>
               <oas3>true</oas3>
               <dateLibrary>java8</dateLibrary>
               <useSpringfox>false</useSpringfox>
               <escapeQuotationMark>true</escapeQuotationMark>
               <escapeUnsafeCharacters>true</escapeUnsafeCharacters>
               <useSpringController>true</useSpringController>
               <useSpringBoot3>true</useSpringBoot3>
               <interfaceOnly>true</interfaceOnly>
               <requestMappingMode>api_interface</requestMappingMode>
               <useBeanValidation>false</useBeanValidation>
            </configOptions>
            <typeMappings>
               <!-- convert Double to BigDecimal -->
               <typeMapping>Double=java.math.BigDecimal</typeMapping>
               <typeMapping>Boolean=boolean</typeMapping>
               <typeMapping>OffsetDateTime=LocalDateTime</typeMapping>
            </typeMappings>
            <importMappings>
               <importMapping>java.time.OffsetDateTime=java.time.LocalDateTime</importMapping>
            </importMappings>
         </configuration>
      </execution>
   </executions>
</plugin>

Steps to reproduce

Related issues/PRs

Suggest a fix

Start by reproducing the issue with the Spring generator and the provided OpenAPI declaration and Maven configuration. Compare the generated AnswerController, AnswersApi, and BaseController behavior when the inherited method is overridden versus left inherited. Done means the Swagger page includes the inherited getAll operation without requiring an override.