struts2学习笔记之十二:struts2对异常的自动处理

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>

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原文地址：https://www.cnblogs.com/djoker/p/6219445.html