How to Manage HttpSession with inactive time period?

[Amanda Mosby]

In the following post , i found about how to mantain session objects
http://www.coderanch.com/t/365859/Servlets/java/session-object-session-ID

specifically

     17 public class SessionListener implements HttpSessionListener{  
     18  
     19     public void init(ServletConfig config){  
     20     }  
     21  
     22     /** 
     23      * Adds sessions to the context scoped HashMap when they begin. 
     24      */  
     25     public void sessionCreated(HttpSessionEvent event){  
     26         HttpSession    session     = event.getSession();  
     27         ServletContext context     = session.getServletContext();  
     28         Map            activeUsers = (Map)context.getAttribute("activeUsers");  
     29  
     30         activeUsers.put(session.getId(), session);  
     31     }  
     32  
     33     /** 
     34      * Removes sessions from the context scoped HashMap when they expire 
     35      * or are invalidated. 
     36      */  
     37     public void sessionDestroyed(HttpSessionEvent event){  
     38         HttpSession    session     = event.getSession();  
     39         ServletContext context     = session.getServletContext();  
     40         Map            activeUsers = (Map)context.getAttribute("activeUsers");  
     41  
     42         activeUsers.remove(session.getId());  
     43     }  
     44 }  

how to use this in my own servlet, how to setHttpSession and getHttpSession
each time i have a new request on my servlet
and how will remove it if the session from the map when its no longer in use again
so is there auto timer for each session, so that it get deleted automatically from the hashmap,
when the given time period is reached and its no longer used by my servlet/server application

[Bear Bibeault]

Your terminology is off. You are not adding or removing "sessions". There is only one session available to your servlet, and you are adding and removing "scoped variables", also called "attributes", to it.

I'm not really understanding what your question is. You can add or remove scoped variables to the session any time you like. All scoped variables in the session will automatically be removed if the session times out.