sessionlistener.java

JSP高级程序员网络开发源代码

package com.jspdev.ch8;

import java.util.Hashtable;

import java.util.Iterator;

import javax.servlet.http.HttpSession;

import javax.servlet.http.HttpSessionEvent;

import javax.servlet.http.HttpSessionListener;

public class SessionListener implements HttpSessionListener {

	// 集合对象，保存session 对象的引用

	static Hashtable ht = new Hashtable();

	// 实现HttpSessionListener接口，完成session创建事件控制

	public void sessionCreated(HttpSessionEvent arg0) {

		HttpSession session = arg0.getSession();

		ht.put(session.getId(), session);

		System.out.println("create session :" + session.getId());

	}

	// 实现HttpSessionListener接口，完成session销毁事件控制

	public void sessionDestroyed(HttpSessionEvent arg0) {

		HttpSession session = arg0.getSession();

		System.out.println("destory session :" + session.getId());

		ht.remove(session.getId());

	}

	// 返回全部session对象集合

	static public Iterator getSet() {

		return ht.values().iterator();

	}

	// 依据session id返回指定的session对象

	static public HttpSession getSession(String sessionId) {

		return (HttpSession) ht.get(sessionId);

	}

}