java监听器实现在线人数统计

本文实例为大家分享了java在线人数统计的具体代码，供大家参考，具体内容如下

1. 项目结构

2. 代码

package com;
 
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
 

@WebListener
public class CountListen implements ServletContextListener {
 
  
  public CountListen() {
    // TODO Auto-generated constructor stub
  }
 
 
  public void contextInitialized(ServletContextEvent arg0) { 
   arg0.getServletContext().setAttribute("count",100);
  }
 
 
  public void contextDestroyed(ServletContextEvent arg0) { 
     // TODO Auto-generated method stub
  }
 
}

package com;
 
import javax.servlet.annotation.WebListener;
import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
 
 
@WebListener
public class SessionListen implements HttpSessionListener, HttpSessionAttributeListener {
 
  public SessionListen() {
    // TODO Auto-generated constructor stub
  }
 
  public void attributeRemoved(HttpSessionBindingEvent arg0) { 
   System.out.println("remove"+"t"+arg0.getName()+arg0.getValue());
  }
 
  public void attributeAdded(HttpSessionBindingEvent arg0) { 
   System.out.println("add"+"t"+arg0.getName()+arg0.getValue());
  }
 
  public void attributeReplaced(HttpSessionBindingEvent arg0) { 
   System.out.println("replace"+"t"+arg0.getName()+arg0.getValue());
  }
 
  public void sessionCreated(HttpSessionEvent arg0) { 
   System.out.println("session create");
 Integer i=(Integer)arg0.getSession().getServletContext().getAttribute("count");
 i++;
 arg0.getSession().getServletContext().setAttribute("count", i);
 
  }
 
  public void sessionDestroyed(HttpSessionEvent arg0) { 
 Integer i=(Integer)arg0.getSession().getServletContext().getAttribute("count");
 i--;
 arg0.getSession().getServletContext().setAttribute("count", i);
 System.out.println("session destroy"+i);
 
  }
 
}

<%@ page language="java" contentType="text/html; charset=UTF-8"
  pageEncoding="UTF-8"%>







<%session.setMaxInactiveInterval(3); %>
当前在线人数:${count}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。