通过session统计访问量

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; }    

}