1 描述
在J2EE项目的开发中，不管是对底层的数据库操作过程，还是业务层的处理过程，还是控制层的处理过程，都不可避免会遇到各种可预知的、不可预知的异常需要处理。每个过程都单独处理异常，系统的代码耦合度高，工作量大且不好统一，维护的工作量也很大。
那么，能不能将所有类型的异常处理从各处理过程解耦出来，这样既保证了相关处理过程的功能较单一，也实现了异常信息的统一处理和维护？答案是肯定的。下面将介绍使用Spring MVC统一处理异常的解决和实现过程。
2 分析
Spring MVC处理异常有3种方式：
（1）使用Spring MVC提供的简单异常处理器SimpleMappingExceptionResolver；
（2）实现Spring的异常处理SimpleMappingExceptionResolver自定义自己的异常处理器；
（3）实现HandlerExceptionResolver 接口自定义异常处理器
（4）使用注解@ExceptionHandler实现异常处理；
3 实战
一:使用Spring MVC提供的简单异常处理器SimpleMappingExceptionResolver
源码介绍:
1.lib包（jar包）和web.
<??><web-app ="http://www.w3.org/2001/ ="http://java.sun.com/ ="http://java.sun.com/ xsi:schemaLocation="http://java.sun.com/ version="2.5"> <display-name></display-name> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:applicationContext.</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list></web-app>
View Code
2.index.jsp（测试页面入口）和 error.jsp（有错误则会跳到此页面）和 hello.jsp（没错误则会跳到此页面）
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>异常处理器测试</title></head><body> <form action="frist.do" method="post"> <input type="submit" value="测试" /> </form></body></html>
View Code
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>这是错误页面</title> </head> <body> 这是错误页面 ${ex.message } </body></html>View Code
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>成功欢迎页面</title> </head> <body> 你竟然没报错<br/> </body></html>
View Code
3.MyController,java(定义自己的处理器)
package cn.zhang.controller;//定义自己的处理器import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;@Controllerpublic class MyController{ @RequestMapping(value="/frist.do",produces="text/html;charset=utf-8",method=RequestMethod.POST) public String frist(){ //制造一个异常 int i=5/0; System.out.println(i); return "forward:/hello.jsp"; }}View Code
4.applicationContext.
<??><beans ="http://www.springframework.org/schema/beans" ="http://www.w3.org/2001/ ="http://www.springframework.org/schema/context" ="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 使用注解方式完成映射 --> <context:component-scan base-package="cn.zhang.controller"></context:component-scan> <!-- mvc的注解驱动 --> <mvc:annotation-driven /> <!-- 注册系统异常处理器 --> <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> <property name="defaultErrorView" value="error.jsp"></property> <property name="exceptionAttribute" value="ex"></property> </bean></beans>
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测试展示:
点击测试，由于我们在自己的处理器制造了一个异常，所以它会跳到错误页面
二:实现Spring的异常处理接口SimpleMappingExceptionResolver自定义自己的异常处理器
源码介绍:
1.lib包和web.
2.error包中是指定错误页面
ageerrors.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><base href="<%=basePath%>"><title>年龄错误页面</title></head><body>年龄错误 ${ex.message }</body></html>View Code
nameerrors.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>名字错误页面</title> </head> <body> 名字错误 ${ex.message } </body></html>View Code
3.MyController.java
package cn.zhang.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import cn.zhang.exception.AgeException;import cn.zhang.exception.NameException;import cn.zhang.exception.UserException;//定义自己的处理器@Controllerpublic class MyController{ @RequestMapping(value="/frist.do") public String frist(Model model,String name,int age) throws UserException{ if (name.equals("admin")) { throw new NameException("用户名错误"); } if (age>50) { throw new AgeException("年龄过大"); } return "forward:/hello.jsp"; }}View Code
4.exception包下，指定我们的异常类
UserException.java
package cn.zhang.exception;//定义UserException继承Exceptionpublic class UserException extends Exception { private static final long serialVersionUID = 1L; public UserException() { super(); // TODO Auto-generated constructor stub } public UserException(String message) { super(message); // TODO Auto-generated constructor stub } }View Code
AgeException.java
package cn.zhang.exception;//继承UserException父类public class AgeException extends UserException { private static final long serialVersionUID = 1L; public AgeException() { super(); // TODO Auto-generated constructor stub } public AgeException(String message) { super(message); // TODO Auto-generated constructor stub } }View Code
NameException.java
package cn.zhang.exception;//继承UserException父类public class NameException extends UserException { private static final long serialVersionUID = 1L; public NameException() { super(); // TODO Auto-generated constructor stub } public NameException(String message) { super(message); // TODO Auto-generated constructor stub }}View Code
5.applicationContext.
<??><beans ="http://www.springframework.org/schema/beans" ="http://www.w3.org/2001/ ="http://www.springframework.org/schema/context" ="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 使用注解方式完成映射 --> <context:component-scan base-package="cn.zhang.controller"></context:component-scan> <!-- mvc的注解驱动 --> <mvc:annotation-driven /> <!-- 实现Spring的异常处理接口HandlerExceptionResolver 自定义自己的异常处理器 --> <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> <property name="defaultErrorView" value="error.jsp"></property> <property name="exceptionAttribute" value="ex"></property> <!-- 指定错误到指定页面 --> <property name="exceptionMappings"> <props> <prop key="cn.zhang.exception.AgeException">error/ageerrors.jsp</prop> <prop key="cn.zhang.exception.NameException">error/nameerrors.jsp</prop> </props> </property> </bean></beans>
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结果展示:
三:实现HandlerExceptionResolver 接口自定义异常处理器
要修改的代码:
1.MyHandlerExceptionResolver.java--定义自己的异常处理器（实现HandlerExceptionResolver接口）
package cn.zhang.resolvers;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.HandlerExceptionResolver;import org.springframework.web.servlet.ModelAndView;import cn.zhang.exception.AgeException;import cn.zhang.exception.NameException;/** * 定义自己的异常处理器（实现HandlerExceptionResolver接口） * @author zhangzong * */public class MyHandlerExceptionResolver implements HandlerExceptionResolver{ public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) { ModelAndView mv=new ModelAndView(); mv.addObject("ex",ex); mv.setViewName("/errors.jsp"); if(ex instanceof NameException){ mv.setViewName("/error/nameerrors.jsp"); } if(ex instanceof AgeException){ mv.setViewName("/error/ageerrors.jsp"); } return mv; } }View Code
2.applicationContext.
<??><beans ="http://www.springframework.org/schema/beans" ="http://www.w3.org/2001/ ="http://www.springframework.org/schema/context" ="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 使用注解方式完成映射 --> <context:component-scan base-package="cn.zhang.controller"></context:component-scan> <!-- mvc的注解驱动 --> <mvc:annotation-driven /> <!-- 注册自定义异常处理器 --> <bean class="cn.zhang.resolvers.MyHandlerExceptionResolver"/></beans>
View Code
其他的相同，不作解释
四:使用注解@ExceptionHandler实现异常处理
源码介绍:
1.其他配置相同（不做解释）
2.MyController.java--继承我们自己定义的注解异常处理器MyHandlerExceptionResolver
package cn.zhang.controller;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import cn.zhang.exception.AgeException;import cn.zhang.exception.NameException;import cn.zhang.exception.UserException;import cn.zhang.resolvers.MyHandlerExceptionResolver;//定义自己的处理器//继承我们自己定义的注解异常处理器MyHandlerExceptionResolver@Controllerpublic class MyController extends MyHandlerExceptionResolver{ @RequestMapping(value="/frist.do") public String frist(Model model,String name,int age) throws UserException{ if (name.equals("admin")) { throw new NameException("用户名错误"); } if (age>50) { throw new AgeException("年龄过大"); } return "forward:/hello.jsp"; }}View Code
3.MyHandlerExceptionResolver.java--定义自己的异常处理器（使用注解）
package cn.zhang.resolvers;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.servlet.ModelAndView;import cn.zhang.exception.AgeException;import cn.zhang.exception.NameException;/** * 定义自己的异常处理器（使用注解） * @author zhangzong * */@Controllerpublic class MyHandlerExceptionResolver{ @ExceptionHandler public ModelAndView resolveException(Exception ex) { ModelAndView mv=new ModelAndView(); mv.addObject("ex",ex); mv.setViewName("/errors.jsp"); if(ex instanceof NameException){ mv.setViewName("/error/nameerrors.jsp"); } if(ex instanceof AgeException){ mv.setViewName("/error/ageerrors.jsp"); } return mv; } }View Code
4.applicationContext.
<??><beans ="http://www.springframework.org/schema/beans" ="http://www.w3.org/2001/ ="http://www.springframework.org/schema/context" ="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 使用注解方式完成映射 --> <context:component-scan base-package="cn.zhang.controller"></context:component-scan> <!-- mvc的注解驱动 --> <mvc:annotation-driven /> <!-- 注册自定义异常处理器 --> <bean class="cn.zhang.resolvers.MyHandlerExceptionResolver"/></beans>
View Code
效果和上相同，这里不做展示
原标题：SpringMVC中的异常处理集锦
关键词：Spring
我知道了 