struts2自定义登录拦截器

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  
  
  <filter>
      <filter-name>struts</filter-name>
      <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  
  <filter-mapping>
      <filter-name>struts</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>
   
</web-app>

package models;

public class User {

    private String username;
    private String password;
    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;
    }
}

package action;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

import models.User;


public class LoginAction {

    private String username;
    private String password;
    
    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 String login(){
        //用户名或密码错误
        if(!"admin".equals(this.username) || !"123456".equals(this.password)){
            ActionContext.getContext().put("errorMsg", "用户名或密码错误！");
            return Action.LOGIN;
        }
        //用户名和密码正确
        else{
            User user=new User();
            user.setUsername(this.username);
            user.setPassword(this.password);
            ActionContext.getContext().getSession().put("user",user);
            return Action.SUCCESS;
        }
    }
}

package action;

import com.opensymphony.xwork2.Action;

public class HomeAction {

    public String index(){
        return Action.SUCCESS;
    }
}

package action;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class LogoutAction {

    public String logout(){
        ActionContext.getContext().getSession().remove("user");
        return Action.SUCCESS;
    }
}

package interceptor;

import models.User;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class LoginInterceptor extends AbstractInterceptor {

    @Override
    public String intercept(ActionInvocation arg0) throws Exception {
        
        //从Session中获取user
        Object user=arg0.getInvocationContext().getSession().get("user");
        if(user==null){              //如果没有user对象
            return Action.LOGIN;    //返回login
        }else{                       //如果有登录
            return arg0.invoke();   //返回Action中method返回的字符串
        }
    }

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>

    <constant name="struts.configuration.xml.reload" value="true"></constant>
    
    <package extends="struts-default" name="default" namespace="/">
        <!-- 配置拦截器 -->
        <interceptors>
            <!-- 配置登录拦截器 -->
            <interceptor name="loginInterceptor" class="interceptor.LoginInterceptor"></interceptor>
            <interceptor-stack name="myInterceptor-stack">
                <interceptor-ref name="defaultStack"></interceptor-ref>
                <interceptor-ref name="loginInterceptor"></interceptor-ref>
            </interceptor-stack>
        </interceptors>
        
        <!-- 修改默认拦截器 -->
        <default-interceptor-ref name="myInterceptor-stack"></default-interceptor-ref>
        
        <!-- 设置全局返回值 -->
        <global-results>
            <result name="login">/login.jsp</result>
        </global-results>
        
        <!-- 配置登录、登出不需要拦截 ,设置拦截器为defaultStack -->
        <action name="Login_login" class="action.LoginAction" method="login">
            <result type="redirectAction">Home_index</result>
            <interceptor-ref name="defaultStack"></interceptor-ref>
        </action>
        <action name="Logout_logout" class="action.LogoutAction" method="logout">
            <result type="redirect">/login.jsp</result>
            <interceptor-ref name="defaultStack"></interceptor-ref>
        </action>
        
        <action name="*_*" class="action.{1}Action" method="{2}">
            <result>/WEB-INF/{1}/{2}.jsp</result>
        </action>    
    </package>
</struts>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8" 
contentType="text/html; charset=utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
  
  </head>
  
  <body>
    <s:form method="post" action="/Login_login">
        <s:textfield name="username" label="用户名"/>
        <s:password name="password" label="密码"/>
        <s:submit></s:submit>
    </s:form>
    
    <s:property value="#errorMsg"/>
  </body>
</html>

<%@ page language="java" import="java.util.*" pageEncoding="utf-8" 
contentType="text/html; charset=utf-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>

  </head>
  
  <body>
        欢迎【<s:property value="#session.user.username"/>】登录   <a href="Logout_logout">退出</a>
  </body>
</html>