Hunsberger, Peter wrote:
Colin Paul Adams <[EMAIL PROTECTED]> writes:
<snip>flow listener discussion,/snip>
I've just read this thread, because I have been trying to work out how to implement pessimistic locking within cocoon. A problem is how to close a database transaction if the user simply walks away from the computer for a few hours, in the middle of a transaction. Session timeout will close the session, but a session listener is needed to then go and rollback the database transaction (or any other such resources held).
Maybe I'm missing something, but why aren't you setting your database
transaction timeout limit to something just a bit larger than the
session timeout? Or, alternatively, if you're using EJB's, set your
container TX timeout? In either case the appropriate catch clause in
your code can then do resource clean up as needed...
Or you can also add store in a session attribute an object implementing javax.servlet.http.HttpSessionBindingListener that will be called whenever the session expires. This allows to perform any cleanup that you need.
Remember however, that holding costly resources like DB connections between request is generally considered bad practice in webapps, because of this very problem of detecting that a user has left.
Sylvain
-- Sylvain Wallez Anyware Technologies http://www.apache.org/~sylvain http://www.anyware-tech.com { XML, Java, Cocoon, OpenSource }*{ Training, Consulting, Projects }
