[javaweb]监听器统计网页在线人数
监听器
1.配置监听器
package com.javaweb.controller;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import java.io.PushbackInputStream;
/**
* @author panglili
* @create 2022-07-20-21:03
*/
public class Listener implements HttpSessionListener {
//session创建
public void sessionCreated(HttpSessionEvent hE) {
ServletContext context = hE.getSession().getServletContext();
Integer o = (Integer)context.getAttribute("onlinecount");
if(o==null){
o=new Integer(1);
}else{
int count=o.intValue();
o=new Integer(count+1);
}
context.setAttribute("o",o);
}
public void sessionDestroyed(HttpSessionEvent hE) {
ServletContext context = hE.getSession().getServletContext();
Integer o = (Integer)context.getAttribute("onlinecount");
if(o==null){
o=new Integer(1);
}else{
int count=o.intValue();
o=new Integer(count+1);
}
context.setAttribute("o",o);
}
}
2.前台实现人数统计
<%--
Created by IntelliJ IDEA.
User: 塔塔
Date: 2022/7/20
Time: 21:12
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>people count:<%= getServletConfig().getServletContext().getAttribute("o")%>...</h1>
</body>
</html>
3.配置web
<listener>
<listener-class>com.javaweb.controller.Listener</listener-class>
</listener>
