I am using struts to construct my web app. Here i need to find out infomations about all the users that are using the app for the moment. And for any user she has to logon and be authenticated to use the app. Right after the authentication , i simply put a context object in a session in order for system to check out if that use is OK to futhur access actions. i just cant count the active sessions as that struts may create session even before the start of user logon process. the key seems to be ckecking if there is the context object in an active session. My question is that which listener i should choose? or is there any other way instead of session listener one, in which i can also do my work with situations above?