Spring MVC Exception Handler 异常的处理

本例以Windows, JDK1.7 为基础，来演示使用Spring MVC 对异常的处理和使用自定义异常。

所使用的相关技术：

Spring 4.3.3.RELEASE
Maven 3
JDK 1.7
Tomcat 7

一，项目结构

本项目采用maven构建，项目结构如下：

二，定义异常

本例才用继承RuntimeException来定义异常：

CustomException.java

package com.devnp.exception;

public class CustomException extends RuntimeException{

	/**
	 * @author duliu
	 */
	private static final long serialVersionUID = 1L;

	private int errorCode ;
	
	private String errorMsg ;

	
	public CustomException() {
		super();
	}

	public CustomException(int errorCode, String errorMsg) {
		super();
		this.errorCode = errorCode;
		this.errorMsg = errorMsg;
	}

	public int getErrorCode() {
		return errorCode;
	}

	public void setErrorCode(int errorCode) {
		this.errorCode = errorCode;
	}

	public String getErrorMsg() {
		return errorMsg;
	}

	public void setErrorMsg(String errorMsg) {
		this.errorMsg = errorMsg;
	}
	
	
}

三，异常的处理

在异常的处理上，使用 @ControllerAdvice 注册异常的Controller, 来处理自定义异常和普通异常。
在对异常的处理上，@ExceptionHandler 注解，可以来接受异常的类型。
CustomExceptionController.java

package com.devnp.controller;

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;

import com.devnp.exception.CustomException;

@ControllerAdvice
public class CustomExceptionController {
	
	//@ExceptionHandlersince spring 3.0

	@ExceptionHandler(CustomException.class) 
	public ModelAndView handleCustomException(CustomException ex) {

		ModelAndView model = new ModelAndView("index");
		
		model.addObject("errorCode", ex.getErrorCode());
		model.addObject("errorMsg", ex.getErrorMsg());

		return model;

	}
	
	@ExceptionHandler(Exception.class)
	public ModelAndView handleAllException(Exception ex) {

		ModelAndView model = new ModelAndView("index");
		
		model.addObject("errorMsg", "This is IO Exception.class");


		return model;

	}
}

四，页面

用来显示异常信息

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Custom Exception</title>
</head>
<body>

<c:if test="${not empty errorCode}">


<h1>${errorCode} : System Errors</h1>


	</c:if>

	<c:if test="${empty errorCode}">


<h1>System Errors</h1>


	</c:if>

	<c:if test="${not empty errorMsg}">


<h2>${errorMsg}</h2>


	</c:if>

</body>
</html>

五，控制器

字啊控制器上面，采用不同的参数来模拟异常的处理
HelloController.java

package com.devnp.controller;

import java.io.IOException;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.devnp.exception.CustomException;

@Controller
public class HelloController {

	/**
	 * 1.当传入参数是error, 抛出自定义异常
	 * 2.当传入参数是io-error, 抛出IO异常
	 * @param type
	 * @return
	 * @throws Exception
	 */
	@RequestMapping(value = "/{type:.+}", method = RequestMethod.GET)
	public ModelAndView getPages(@PathVariable("type") String type) throws Exception {

	  if ("error".equals(type)) {
		//抛出自定义异常
		throw new CustomException(1001, "This is custom message");
	  } else if ("io-error".equals(type)) {
		// 抛出系统异常
		throw new IOException();
		
	  } else {
		return new ModelAndView("index").addObject("errorMsg", type);
	  }

	}
}