Struts2实现显示在线人数

墨蓝 2022-04-23 10:30 180阅读 0赞

登录成功以后将用户信息放入Session域中（在线人数+1）

在线人数信息保存在application域中

登出时使session直接失效（在线人数-1）

index

<%@ 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>
      <h3>欢迎登陆</h3>
    		<form action="user_login" method="post">
    		用户名 <input type="text"name="username"/><br/>
    		密码 <input type="password"name="password"/><br/>
    		<input type="submit" value="登录"/><br/>
    		</form>
    </body>
    </html>

success

<%@ 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>登录成功</title>
    </head>
    <body>
    	<h1>欢迎${sessionScope.loginUser}登录！</h1>
    	<h3>当前在线人数：${applicationScope.count}</h3>
    	<h1><a href="user_logout">登出</a></h1>
    </body>
    </html>

logout

Struts.xml

<?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.enable.DynamicMethodInvocation" value="false" />
    	<constant name="struts.devMode" value="true" />
    
    	<package name="default" namespace="/" extends="struts-default">
    		<action name="user_login" class="com.Action.UserAction"
    			method="login">
    			<result>/WEB-INF/views/success.jsp</result>
    		<allowed-methods>*</allowed-methods>
    		</action>
    		
    		<action name="user_logout" class="com.Action.UserAction"
    			method="logout">
    			<result>/WEB-INF/views/baby.jsp</result>
    		<allowed-methods>*</allowed-methods>
    		</action>
    		
    	</package>
    
    
    </struts>

UserAction

package com.Action;
    
    import java.util.Map;
    
    import org.apache.struts2.dispatcher.SessionMap;
    import org.apache.struts2.interceptor.ApplicationAware;
    import org.apache.struts2.interceptor.SessionAware;
    
    
    public class UserAction implements SessionAware,ApplicationAware{
    
    	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 logout() {
    		
    		((SessionMap)session).invalidate();
    	
    			return "success";
    		
    	}
    	
    	public String login() {
    		
    		if (session.get("loginUser") != null) {
    			return "success";
    		}
    		
    		System.out.println(username+password);
    		session.put("loginUser",username);
    		
    		Integer count = (Integer) application.get("count");
    		
    		if (count == null) {
    			count = 0;
    		}
    		
    		application.put("count", count+1);
    		
    		return "success";
    	}
    	
    	private Map<String, Object>session;
    	
    	@Override
    	public void setSession(Map<String, Object> arg0) {
    		this.session = arg0;
    		
    	}
    	
    	private Map<String, Object>application;
    	
    	@Override
    	public void setApplication(Map<String, Object> arg0) {
    		this.application = arg0;
    		
    	}
    	
    }