求一段代码（关于WEB监听）

Question

我想创建一个监听的SERVLET，监听用户的SESSION是否失效，请问如何写啊？

Answer 1

看看这个
http://www.javaresearch.org/article/showarticle.jsp?column=2&thread=16478

Answer 2

package com.hnii.ccs.ccso.listener;import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;import javax.servlet.http.HttpSessionListener;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
import javax.servlet.http.HttpSessionActivationListener;
import javax.servlet.http.HttpSessionAttributeListener;
import javax.servlet.http.HttpSessionActivationListener;
import com.hnii.comm.db.DBConn;
import com.hnii.ccs.ccso.db.InitVisitNum;
public class VisitNumListener implements HttpSessionListener,HttpSessionActivationListener,
                                            HttpSessionBindingListener,HttpSessionAttributeListener,
                                            ServletContextListener
{
//private static int num;
//private void persistenNum()
//{
// if(num==100)
// {
// InitVisitNum.updNum();
// num=0;
// }
//}
public void sessionDidActivate(HttpSessionEvent event)
{
}
public void sessionWillPassivate(HttpSessionEvent event)
{
}
public void valueBound(HttpSessionBindingEvent event)
{
}
public void valueUnbound(HttpSessionBindingEvent event)
{
}
public void attributeAdded(HttpSessionBindingEvent event)
{
}
public void attributeRemoved(HttpSessionBindingEvent event)
{
}
public void attributeReplaced(HttpSessionBindingEvent event)
{
}
public void sessionCreated(HttpSessionEvent event)
{
//num++;
InitVisitNum.addCountNum();
InitVisitNum.addNowNum();
InitVisitNum.addCount();
}
public void sessionDestroyed(HttpSessionEvent event)
{
InitVisitNum.mimusNowNum();
}
public void contextDestroyed(ServletContextEvent event)
{
}
public void contextInitialized(ServletContextEvent event)
{
}
}