首先寫個類:
- 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;
- }
- }
- 然後配置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 (注意此處)
- </listener-class>
- </listener>
- *****************************************
- </web-app>
- 建個JSP測試:
- 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>無標題文檔</title>
- <body bgcolor="#FFFFFF">
- 在線人數:<%=SessionCounter.getActiveSessions()%>
- </body>
- </html>
看看可以實現不?我也是找到的,我用了,可以統計出來.
