package com.newegg.shopping.util.listener;

import javax.servlet.http.HttpSessionAttributeListener;

import javax.servlet.http.HttpSessionBindingEvent;

import javax.servlet.http.HttpSessionEvent;

import javax.servlet.http.HttpSessionListener;

public class LoggedUserCounter implements HttpSessionListener, HttpSessionAttributeListener {

	private static int count = 0;

	public void sessionCreated(HttpSessionEvent event) {

System.out.println("------------session created!");

	}

	public void sessionDestroyed(HttpSessionEvent event) {

	}

	public void attributeAdded(HttpSessionBindingEvent event) {

		if(event.getName().equals("admin") && ((String)event.getValue()).equals("admin")) {

			count ++;

			System.out.println("a user logged in ! now total :" + count);

		}

	}

	public void attributeRemoved(HttpSessionBindingEvent arg0) {

	}

	public void attributeReplaced(HttpSessionBindingEvent arg0) {

	}

}

可折叠代码块package com.newegg.shopping.util.listener;

import javax.servlet.http.HttpSessionAttributeListener;

import javax.servlet.http.HttpSessionBindingEvent;

import javax.servlet.http.HttpSessionEvent;

import javax.servlet.http.HttpSessionListener;

public class LoggedUserCounter implements HttpSessionListener, HttpSessionAttributeListener {

	private static int count = 0;

	public void sessionCreated(HttpSessionEvent event) {

System.out.println("------------session created!");

	}

	public void sessionDestroyed(HttpSessionEvent event) {

	}

	public void attributeAdded(HttpSessionBindingEvent event) {

		if(event.getName().equals("admin") && ((String)event.getValue()).equals("admin")) {

			count ++;

			System.out.println("a user logged in ! now total :" + count);

		}

	}

	public void attributeRemoved(HttpSessionBindingEvent arg0) {

	}

	public void attributeReplaced(HttpSessionBindingEvent arg0) {

	}

}