package com.kaka.listener;

import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import org.apache.log4j.Logger;

/**
 * 
 * @author kaka
 *
 */
public class OnlineUserCounterListener implements HttpSessionListener{
	private Logger logger = Logger.getLogger(OnlineUserCounterListener.class);
	public void sessionCreated(HttpSessionEvent event) {
		logger.info("create session");
		HttpSession session = event.getSession();
		String sessionId = session.getId();
		System.out.println(sessionId);
	}

	@SuppressWarnings("unchecked")
	public void sessionDestroyed(HttpSessionEvent event) {
		logger.info("session失效");
		HttpSession session = event.getSession();
		ServletContext application = session.getServletContext();
		String userName = (String) session.getAttribute("username");
		List<String> list = (List<String>) application.getAttribute("userlist");
		if(list.contains(userName)){
			list.remove(userName);
			logger.info("系统移除用户"+userName);
		}
		System.out.println(session.getId());
	}

}