jsp实现在线人数统计

来源:微学计算机考试发布时间:2008-07-16

  首先写个类:

  import javax.servlet.*;

  import javax.servlet.http.*;

  public class SessionCounter implements HttpSessionListener {

  private static int activeSessions = 0;

  public void sessionCreated(HttpSessionEvent se) {

  activeSessions++;

  }

  public void sessionDestroyed(HttpSessionEvent se) {

  if(activeSessions > 0)

  activeSessions--;

  }

  public static int getActiveSessions() {

  return activeSessions;

  }

  }

  然后配置web.xml

  <?xml version="1.0" encoding="UTF-8"?>

  <web-app version="2.4"

  xmlns="http://java.sun.com/xml/ns/j2ee"

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee

  http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

  ****************************************

  <!-- Listeners -->

  <listener>

  <listener-class>

  SessionCount.SessionCounter (注意此处)

  </listener-class>

  </listener>

  *****************************************

  </web-app>

  建个JSP测试:

  test.jsp

  <%@ page language="Java" contentType="text/html;charset=GBK"%>

  <%@ page import="java.sql.*"%>

  <%@ page import="SessionCount.SessionCounter" %>

  <html>

  <head>

  <meta http-equiv="Content-Type" content="text/html; charset=GBK">

  <title>无标题文档</title>

  <body bgcolor="#FFFFFF">

  在线人数:<%=SessionCounter.getActiveSessions()%>

  </body>

  </html>

  看看可以实现不?我也是找到的,我用了,可以统计出来.