How do I know a user has been logged out from another screen

Question

If one user is already logged in to the web application and another user with the same user name and password trying to log in to the same web application, i need to logout the first screen's user session. In other word, I want to disable first screen access right since it has been logged out.
I have a user log class to record users login activities. A new user log object will be created for every login.
How should I do that?

Answer 1

Try to write an implementation of HttpSessionListener and HttpSessionAttributeListener something like the one down below and configure it accordingly.Believe tht should very well cater your requirment.
public SessionAttributeListener implements HttpSessionAttributeListener,HttpSessionListner{
   List<HttpSession> sessionsList;
    public SessionAttributeListener(){
         this.sessionsList = new ArrayList<HttpSession>();   
    public void sessionCreated(HttpSessionEvent se){
    public void sessionDestroyed(HttpSessionEvent se) {
            this.sessionList.remove(se.getSession());
    public void attributeAdded(HttpSessionBindingEvent se){
                if(se.getName().equals("userInfo"))
                     this.appAction(se);
    public void attributeRemoved(HttpSessionBindingEvent se){
              if(se.getName().equals("userInfo"))
                        this.sessionsList.remove(se.getSession());  
    public void attributeReplaced(HttpSessionBindingEvent se) {
    private void appAction(HttpSessionBindingEvent se){
                UserBean ub = (UserBean)se.getValue();
                 for(HttpSession session:this.sessionsList) {
                         UserBean ub1 = (UserBean)session.getAttribute("userInfo"); 
                         if(ub1.getUserName().equals(ub.getUserName())){
                                try{
                                   session.removeAttribute("userInfo");
                                   session.invalidate();
                               }catch(Exception exp){}
                this.sessionsList.add(se.getSession());
}Hope this might give you a brief idea of how to go about. :)
REGARDS,
RaHuL