Spring MVC handle Exceptions in Controller using @ExceptionHandler

Points To Remember

• You can handle all types of runtime exceptions and custom exceptions using @ExceptionHandler annotation. 
• You just need to define the class to the annotation to handle exceptions of that class.

Spring MVC handle Exceptions in Controller

Here we have a simple Spring MVC application with the following.

• HomeController wih three actions 
• throw1 - throws Custom exception
• throw2 - throws Custom exception
• throw3 - throws Runtime exception

Home Controller

package com.ekiras.controller;

import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.ekiras.exception.MyException;
import com.ekiras.exception.MyGlobalException;

@Controller
public class HomeController {
 
 private static final Logger logger = LoggerFactory.getLogger(HomeController.class);
 
 @RequestMapping(value = "/", method = RequestMethod.GET)
 public String home(Locale locale, Model model) {
  logger.info("Welcome home! The client locale is {}.", locale);
  
  Date date = new Date();
  DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);
  
  String formattedDate = dateFormat.format(date);
  
  model.addAttribute("serverTime", formattedDate );
  
  return "home";
 }
 
 @RequestMapping(value="/throw1")
 public String throw1(){
  throw new MyException();
 }
 

 @RequestMapping(value="/throw2")
 public String throw2(){
  throw new MyGlobalException();
 }

 @RequestMapping(value="/throw3")
 public String throw3(){
  throw new RuntimeException();
 }
 

 
 @ResponseBody
 @ExceptionHandler(MyException.class)
 public String myException(MyException exception){
  return "exception caught message="+ exception.getMessage();
 }

 @ResponseBody
 @ExceptionHandler(MyGlobalException.class)
 public String myGlobalException(MyGlobalException exception){
  return "exception caught message="+ exception.getMessage();
 }
 
}

The above code will not catch any  Exception of class RuntimeException.  If you want to catch it you can add another method like following to your code.

 @ResponseBody
 @ExceptionHandler(Exception.class)
 public String myGlobalException(Exception exception){
  return "exception caught message="+ exception.getMessage();
 }

Now, after adding the above code to your controller. Your controller will handle all types of Exceptions.