通过sessionId获取session

通过HttpSessionListener监听器和全局静态map自己实现一个SessionContext。

MySessionContext.Java:

public class MySessionContext {     private static HashMap mymap = new HashMap();

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

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

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

MySessionListener.java:

public class MySessionListener implements HttpSessionListener {     public void sessionCreated(HttpSessionEvent httpSessionEvent) {     MySessionContext.AddSession(httpSessionEvent.getSession());     }

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

}

web.xml添加一个监听器：

<listener> <listener-class>listener.MySessionListener</listener-class> </listener>

根据sessionId获取Session对象：

String sessionId = request.getParameter("sessionId");

HttpSession session = MySessionContext.getSession(sessionId);