Context Listener

[Neeraj Vij]

Hi,

How can we use context listener in real-time applications.

Regards,
Neeraj.

[Ben Souther]

Does your app have anything that needs to be initialized at startup?
Does it have anything that needs to be cleaned up at shutdown?
If so, a ContextListener is just the thing for you.

[Neeraj Vij]

Hi Ben,

Thanx for the reply...I justed wanted for improving my knowledge.

Can u provide some scenario, where u have used context-listner. In books I have read for db connections etc. but not satisfied with them..

Regards,
Neeraj.

[Ben Souther]

True not too many people would make a DB connection in a listener.

It would make sense, however to initialize a connection pool from a listener.
You may also have initialization data that is stored in a database that you want to retrieve and cache when the context initializes.

I have a webservice app that communicates with a non-browser application.
In it there is a login handshake that gives the client an ID string (similar to a JSPSessionID). I have an in-memory object that keeps track of who's logged in and when their session expires. So that I can restart the application without throwing all of these clients out, I serialize that object to disk when the context is destroyed and de-serialize it when the context starts back up.

[Neeraj Vij]

Hi,

thnx Ben for all your inputs.

Regards,
Neeraj.