struts2学习笔记之十二:struts2对异常的自动处理

时间:2021-11-05 14:48:47
在UserAction类中引发异常,但是不处理
package com.djoker.struts2;

import java.util.Date;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.Action;

public class UserAction {

    private String username;

    private String password;

    private Date createDate;

    public String getUsername() {
return username;
} public void setUsername(String username) {
this.username = username;
} public String getPassword() {
return password;
} public void setPassword(String password) {
this.password = password;
} public Date getCreateDate() {
return createDate;
} public void setCreateDate(Date createDate) {
this.createDate = createDate;
} public String addUser() throws Exception {
if("admin".equals(username)){
throw new UserNotFoundException("账号没有找到");
}
ServletActionContext.getRequest().setAttribute("username", username);
ServletActionContext.getRequest().setAttribute("password", password);
ServletActionContext.getRequest().setAttribute("createDate", createDate);
return Action.SUCCESS;
}
}
UserNotFoundException.java类
package com.djoker.struts2;

public class UserNotFoundException extends RuntimeException {

    public UserNotFoundException() {
super();
// TODO Auto-generated constructor stub
} public UserNotFoundException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
} public UserNotFoundException(String message) {
super(message);
// TODO Auto-generated constructor stub
} public UserNotFoundException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
} }
配置文件中可以配置全局异常和局部异常
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd"> <struts>
<package name="user" extends="struts-default" namespace="/user">
<global-exception-mappings>
<exception-mapping result="error" exception="com.djoker.struts2.UserNotFoundException"></exception-mapping>
</global-exception-mappings>
<action name="*User" class="com.djoker.struts2.UserAction" method="{1}User">
<exception-mapping result="error" exception="com.djoker.struts2.UserNotFoundException"></exception-mapping>
<result>/success.jsp</result>
<result name="error">/error.jsp</result>
</action>
</package>
</struts>
错误后的跳转页面error.jsp,可以使用el表达式取得异常信息
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<!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=GB18030">
<title>Insert title here</title>
</head>
<body>
<h1>登录失败</h1>
<!-- 获取异常信息 -->
${exception.message }<br>
<!-- 获取异常堆栈信息 -->
${exceptionStack }<br>
</body>
</html>