//java 代码
public class SessionCounter implements HttpSessionListener { private static int activeSessions = 0; //session创建时执行 public void sessionCreated(HttpSessionEvent se) { activeSessions++; } //session销毁时执行 public void sessionDestroyed(HttpSessionEvent se) { if (activeSessions > 0) activeSessions--; } //获取活动的session个数(在线人数) public static int getActiveSessions() { return activeSessions; } }
//web.xml添加配置
<listener>
<listener-class>com.java.webutils.SessionListener</listener-class>
</listener>
//jsp页面编写
<%@ page import="com.my.count.SessionCounter"%>
<body>
在线人数为:<%=SessionCounter.getActiveSessions()%>
</body>