Spring 3 MVC Exception Handling with @ExceptionHandler and @ResponseStatus

@ExceptionHandler : It is method annotation within a controller to specify which method is invoked when an exception of a specific type is thrown during the execution of controller methods.

@ResponseStatus : It marks a method or exception class with the status code and reason that should be returned. The status code is applied to the HTTP response when the handler method is invoked, or whenever said exception is thrown.

Example : will see how these two annotaions work

1. Defined exception class ( will throw from controller)

 
package com.exception;

public class UserDefinedException extends RuntimeException{


 private static final long serialVersionUID = 1L;
 public String message;
 
 public UserDefinedException(String message) {
  this.message = message;
 }

 @Override
 public String getMessage() {
  return message;
 }
}

2.Controller

 
package com.controller;

import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseStatus;

import com.exception.UserDefinedException;


@Controller
public class ExceptionDemo {

 @RequestMapping("/welcome")
 public String userDefinedExceptionDemo(){
  boolean exception = true;
  
  if(exception){
   throw new UserDefinedException("exception in controller"); // throw user defined exception
  }
  return "welcome";
 }
 
 @ExceptionHandler(UserDefinedException.class)
 @ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "user defined response status")
 public void handleUserDefinedException(){
  
  
 }
}

First method :  Whenever user hit the URL ("../welcome") it will throw user defined exception
Second method : - When the exception ( UserDefinedException )occurs in controller, the method will call and will set the response status.
3.Configuration

 


 

 
  
   /WEB-INF/jsps/
  
  
   .jsp
  

Not defined any exception handling to configuration
Result:
if you hit the URL "http://localhost:8080/SpringMVCDemo/welcome" you can see the user defined status on browser.