Thread: Track the user session list

I take it you are handling the login/logout your self, as in looking up the user credentials from somewhere and matching them with the user input.

Just have it so that whenever a login is performed you add the user to a list of logged in users, maybe a static list somewhere like a SessionStatistics class or whatever.

Whenever a user logs out you remove the user from the list. Better make the list a map I guess.

However if you also which to make sure that whenever a session is destroyed by the application server you can have your session manager implement HttpSessionListener.

Here is a quick example.

public class SessionManager implements HttpSessionListener {
 
        @Override
	public void sessionCreated(HttpSessionEvent sessionEvent) {
            // This is called whenever a new session is created, no matter if the user is logged in or not
	}
 
        @Override
	public void sessionDestroyed(HttpSessionEvent sessionEvent) {
            // This is called whenever a session is destroyed
            // In here you can have some code that gets the session off the sessionEvent object and then checks to see if this session represents a user who was logged in. Since the session is now about to be destroyed you can then safely remove that user from your map/list of logged in users.
        }
}

Of course you also need to add this listener in your web.xml file.

    <listener>
        <listener-class>my.package.name.SessionManager</listener-class>
    </listener>

Hope that makes any sense. If you need more help in looking at the specific code for adding/removing the user from the map/list, let us know and I shall see what I can do.

// Json