当dispatchServlet接收到controller抛出的异常时，会将异常交由 HandlerExceptionResolver
异常处理器处理！我们可以创建自定义异常处理器实现该接口来处理自定义异常
1） 自定义异常类
public class MyException extends Exception { // 异常信息 private String message; public MyException() { super(); } public MyException(String message) { super(); this.message = message; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } }
2）自定义异常处理器
public class CustomHandleException implements HandlerExceptionResolver { @Override public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exception) { // 定义异常信息 String msg; // 判断异常类型 if (exception instanceof MyException) { // 如果是自定义异常，读取异常信息 msg = exception.getMessage(); } else { // 如果是运行时异常，则取错误堆栈，从堆栈中获取异常信息 Writer out = new StringWriter(); PrintWriter s = new PrintWriter(out); exception.printStackTrace(s); msg = out.toString(); } // 把错误信息发给相关人员,邮件,短信等方式 // TODO // 返回错误页面，给用户友好页面显示错误信息 ModelAndView modelAndView = new ModelAndView(); modelAndView.addObject("msg", msg); modelAndView.setViewName("error"); return modelAndView; } }
3）在springmvc.xml中配置异常处理器
<!-- 配置全局异常处理器 --> <bean id="customHandleException" class="cn.itcast.ssm.exception.CustomHandleException"/>
4）定制错误页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>系统发生异常了！</h1>
<br />
<h1>异常信息</h1>
<br />
<h2>${msg }</h2>
</body>
</html>
5）测试异常处理
@RequestMapping(value = "/item/itemlist.action") public ModelAndView itemList() throws MyException{ List<Items> list = itemService.selectItemsList(); if(true){ throw new MyException("商品列表不能为空！！"); } ModelAndView mav = new ModelAndView(); mav.addObject("itemList", list); mav.setViewName("itemList"); return mav; }
