SpringMVC异常处理
异常处理思路
- Controller调用service，service调用dao，异常都是向上抛出的，最终有DispatcherServlet找异常处理器进 行异常的处理。
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SpringMVC的异常处理
自定义异常类
package cn.itcast.exception;
/**
* 自定义异常类
*/
public class SysException extends Exception{
// 存储提示信息的
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public SysException(String message) {
this.message = message;
}
}
自定义异常处理器
package cn.itcast.exception;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 异常处理器
*/
public class SysExceptionResolver implements HandlerExceptionResolver{
/**
* 处理异常业务逻辑
* @param request
* @param response
* @param handler
* @param ex
* @return
*/
public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
// 获取到异常对象
SysException e = null;
if(ex instanceof SysException){
e = (SysException)ex;
}else{
e = new SysException("系统正在维护....");
}
// 创建ModelAndView对象
ModelAndView mv = new ModelAndView();
mv.addObject("errorMsg",e.getMessage());
mv.setViewName("error");
return mv;
}
}
配置异常处理器
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 开启注解扫描 -->
<context:component-scan base-package="cn.itcast"/>
<!-- 视图解析器对象 -->
<bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--前端控制器，哪些静态资源不拦截-->
<mvc:resources location="/css/" mapping="/css/**"/>
<mvc:resources location="/images/" mapping="/images/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<!--配置异常处理器-->
<bean id="sysExceptionResolver" class="cn.itcast.exception.SysExceptionResolver"/>
<!-- 开启SpringMVC框架注解的支持 -->
<mvc:annotation-driven />
</beans>
Usercontolle.java
package cn.itcast.controller;
import cn.itcast.exception.SysException;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping("/user")
public class UserController {
@RequestMapping("/testException")
public String testException() throws SysException{
System.out.println("testException执行了...");
try {
// 模拟异常
int a = 10/0;
} catch (Exception e) {
// 打印异常信息
e.printStackTrace();
// 抛出自定义异常信息
throw new SysException("查询所有用户出现错误了...");
}
return "success";
}
}
index.jsp
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2018/5/5
Time: 22:08
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>异常处理</h3>
<a href="user/testException" >异常处理</a>
</body>
</html>