监听器

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package cn.toher.listener;

import cn.toher.bean.User;
import cn.toher.dao.UserLogDao;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

/**
 *
 * @author Administrator
 */
public class SessionListener implements HttpSessionListener {

    public SessionListener() {
    }

    ;

    @Override
    public void sessionCreated(HttpSessionEvent se) {
    }

    @Override
    public void sessionDestroyed(HttpSessionEvent se) {
        HttpSession session = se.getSession();
        User user = (User) session.getAttribute("Suser");
// 监听session中的user，如果它为空，则去动作
        if (user != null) {
            UserLogDao userLogDao = new UserLogDao();
            userLogDao.addTimeout(user);
        }
    }
}

监听器

原文：http://www.cnblogs.com/itchenfirst/p/7287035.html