Java根据sessionId获取Session对象

1. 建立一个自己的SessionContext：

程序代码：

 package cn.org.jshuwei.session.core;

 import javax.servlet.http.HttpSession;
 import java.util.HashMap;

 public class MySessionContext {
 private static MySessionContext instance;
 private HashMap mymap;

 private MySessionContext() {
 mymap = new HashMap();
 }

 public static MySessionContext getInstance() {
 if (instance == null) {
 instance = new MySessionContext();
 }
 return instance;
 }

 public synchronized void AddSession(HttpSession session) {
 if (session != null) {
 mymap.put(session.getId(), session);
 }
 }

 public synchronized void DelSession(HttpSession session) {
 if (session != null) {
 mymap.remove(session.getId());
 }
 }

 public synchronized HttpSession getSession(String session_id) {
 if (session_id == null) return null;
 return (HttpSession) mymap.get(session_id);
 }

 }

 

2.新建一个Session监听

 

程序代码

 package cn.org.jshuwei.session.core;

 import javax.servlet.http.HttpSessionListener;
 import javax.servlet.http.HttpSessionEvent;
 import javax.servlet.http.HttpSession;
 import java.util.HashMap;
 import java.util.Map;

 public class SessionListener implements HttpSessionListener {
 public static Map userMap = new HashMap();
 private   MySessionContext myc=MySessionContext.getInstance();

 public void sessionCreated(HttpSessionEvent httpSessionEvent) {
 myc.AddSession(httpSessionEvent.getSession());
 }

 public void sessionDestroyed(HttpSessionEvent httpSessionEvent) {
 HttpSession session = httpSessionEvent.getSession();
 myc.DelSession(session);
 }
 }

 

3.在web.xml中配置

 

程序代码

 <listener>
 <listener-class>cn.org.jshuwei.session.core.SessionListener</listener-class>
 </listener>

 

4.使用

程序代码

 MySessionContext myc= MySessionContext.getInstance();
 HttpSession sess = myc.getSession(sessionId);