Inherited Methods Not Included in Swagger Documentation with @RouterOperation in Spring Boot WebFlux Application

[oms12]

Describe the bug

When using @RouterOperation to document API endpoints in Spring Boot Webflux applications with springdoc-openapi, the Swagger does not include methods inherited from parent classes. This occurs because internally, AopUtils.getTargetClass(handlerBean).getDeclaredMethods() is used, which only retrieves declared methods, not methods from parent classes.

Because suppose there is a method already implemented in parent class and I don't want to implement that method again in child class and the method implemented in the parentClass is my beanMethod.
Since that method is already inherited by the child class it should be child class function also.

To Reproduce

1. Specify @RouterOperation for an endpoint in a Spring Boot application.
2. Define a method in a subclass that overrides a method from a parent class and parent class method is the beanMethod.
3. Check the generated Swagger documentation.

Spring Boot version: 3
springdoc-openapi module version:

        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-starter-webflux-ui</artifactId>
            <version>2.3.0</version>
        </dependency>

Expected behavior

Swagger documentation should include methods inherited from parent classes when using @RouterOperation.

Screenshots

Additional context
Code where beanClass and beanMethod is used.
@RouterOperation(path = "v1/payment", method = RequestMethod.POST, beanClass = PaymentHandler.class, beanMethod = "handle", operation = @Operation(description = "Say hello GET", operationId = "lowercaseGET", tags = "persons"))

[bnasslahsen]

@oms12,

Try adding a complete reproducible sample, so we can confirm the fix.
Feel free to provide a Minimal, Reproducible Example - with HelloController that reproduces the problem.

This ticket will be closed, but can be reopened if your provide the reproducible sample.

[oms12]

Sure, I will add the one simple code to reproduce the issue.

[oms12]

Hi @bnasslahsen
To Reproduce the issue
BaseHandler Class

package com.example.swagger.Handler;

import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;

@Component
public abstract class BaseHandler {
    protected abstract Mono<ServerResponse> apply (ServerRequest serverRequest);

    public Mono<ServerResponse> handle(ServerRequest serverRequest) {
        return this.apply(serverRequest);
    }
}

GetNameHandlerClass

package com.example.swagger.Handler;

import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;

@Component
public class GetNameHandler extends BaseHandler{
    @Override
    protected Mono<ServerResponse> apply(ServerRequest serverRequest) {
        return ServerResponse.ok()
                .contentType(MediaType.APPLICATION_JSON)
                .bodyValue("Name API is called");
    }

    // Since handle function is present in the BaseHandler class so it is not able to detect but it should

    // Uncommenting below code will work as expected since now explicitly handle is declared here

//    @Override
//    public Mono<ServerResponse> handle(ServerRequest serverRequest) {
//        return super.handle(serverRequest);
//    }
}

Router Class I am using Functional Endpoint

package com.example.swagger.Router;

import com.example.swagger.Handler.GetNameHandler;
import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.media.Content;
import io.swagger.v3.oas.annotations.media.Schema;
import io.swagger.v3.oas.annotations.responses.ApiResponse;
import org.springdoc.core.annotations.RouterOperation;
import org.springdoc.core.annotations.RouterOperations;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.reactive.function.server.RequestPredicates;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.RouterFunctions;
import org.springframework.web.reactive.function.server.ServerResponse;


@Configuration
public class GetNameRouter {

    @Bean
    @RouterOperations(
            value = {
                    @RouterOperation(path = "/v1/name", produces = {MediaType.APPLICATION_JSON_VALUE}, method = RequestMethod.GET,
                            beanClass = GetNameHandler.class, beanMethod = "handle", operation = @Operation(operationId = "getName",
                            description = "get name", responses = {@ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(implementation = String.class)))})
                    )
            })

    public RouterFunction<ServerResponse> routerFunction(GetNameHandler getNameHandler) {
        return RouterFunctions.route(RequestPredicates.GET("/v1/name"), getNameHandler::handle);
    }

}

In the GetNameHandler class I am commenting and uncommenting the code, I am getting the results as below.
Hitting this url - http://localhost:8080/v1/swagger/swagger-ui.html

This is the result of keeping the code commented.

This is the result of uncommented code.

Below is repo link of the simple Spring-Boot working code of above example.
https://github.com/oms12/Swagger

Please clone and check the results I mentioned above.

Please let me know if anything wrong I am doing or any clarification regarding my code.