Error creating bean with name 'handlerExceptionResolver' defined in class path resource

Question

I have a simple project where I have created custom exception handling. Funny thing is when I compile this project it gives me an error.

Error creating bean with name 'handlerExceptionResolver' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerExceptionResolver]: Factory method 'handlerExceptionResolver' threw exception; nested exception is java.lang.IllegalStateException: Ambiguous @ExceptionHandler method mapped for [class java.lang.Exception]: {public final org.springframework.http.ResponseEntity com.winwinit.rest.microservices.restfulwebservices.Exception.CustomizedEntityExceptionResponse.handleAllUserException(java.lang.Exception,org.springframework.web.context.request.WebRequest), public final org.springframework.http.ResponseEntity com.winwinit.rest.microservices.restfulwebservices.Exception.CustomizedEntityExceptionResponse.handleAllException(java.lang.Exception,org.springframework.web.context.request.WebRequest)}
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]

package com.winwinit.rest.microservices.restfulwebservices.Exception;

import java.util.Date;

import org.omg.CORBA.portable.UnknownException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;


import com.winwinit.rest.microservices.restfulwebservices.User.UserNotFoundException;

@ControllerAdvice
@RestController
public class CustomizedEntityExceptionResponse extends 
    ResponseEntityExceptionHandler{

    @ExceptionHandler(Exception.class)
    public final ResponseEntity<Object> handleAllException(Exception ex, WebRequest request)  {
        ExceptionResponse exceptionResponse = new ExceptionResponse(new Date(), ex.getMessage(), request.getDescription(false));    
        return new ResponseEntity(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
    }


    @ExceptionHandler(Exception.class)
    public final ResponseEntity<Object> handleAllUserException(Exception ex, WebRequest request)  {
        exceptionResponse exceptionResponse = new ExceptionResponse(new Date(), ex.getMessage(), request.getDescription(false));
        return new ResponseEntity(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
    }


    @ExceptionHandler(Exception.class)
    public final ResponseEntity<Object> handleUserNotFoundException(UnknownException ex, WebRequest request)  {
        ExceptionResponse exceptionResponse = new ExceptionResponse(new Date(), ex.getMessage(), request.getDescription(false));
        return new ResponseEntity(exceptionResponse, HttpStatus.NOT_FOUND);
    }

}

When I comment 'handleUserNotFoundException' function it works fine however when I add this method it gives me that error. Why would Spring cannot handle it? Any help will be greatly appreciated.

I removed function 'handleUserNotFoundException' and it works fine.. Also when i just remove ExceptionHandler annotation and compile it works fine.

Answer 1

The error message is meaningful, it's says Ambiguous @ExceptionHandler method because you have two method mapped for same exception which is Exception.class

handleAllUserException

@ExceptionHandler(Exception.class)
public final ResponseEntity<Object> handleAllUserException(Exception ex, WebRequest request)  

handleUserNotFoundException

 @ExceptionHandler(Exception.class)
 public final ResponseEntity<Object> handleUserNotFoundException(UnknownException ex, WebRequest request)  

Both the methods are mapped for Exception.class which is Ambiguous for container thread to pick at runtime, change the handleUserNotFoundException method mapping to UnknownException

@ExceptionHandler(UnknownException.class)
public final ResponseEntity<Object> handleUserNotFoundException(UnknownException ex, WebRequest request)