Alexey Maslov schrieb: > I'd add one more question - is > "session-per-conversation" approach suitable for > shopping cart scenario: ShoppingCart instance lives > for the application lifespan and persistent objects > (say ProductItem) are added and removed? I'm asking > because we had some problems with > "session-per-conversation" concerning objects that did > not have clear conversation boundaries. >
I cannot clearly say, but to my knowlege you can have multiple conversations. The shopping cart szenario is somewhat different, because this is clearly a case for a session scope and not a limited conversation. So with a shopping cart you are better of with a session.merge instead of keeping the db session open. I only can talk as an outsider here, since I do not have any affiliation with Seam or the jboss guys. the way I see it the opensession in conversation is more suitable for szenarios where you load a set of objects and then do something within the same form or 1-2 subsequent forms, the typical crud szenario. That way you can gain the comfort of statefulness and not having objects out of a session during the lifetime of your use case. But I do not see any reason to have that in a shopping cart, because keeping a session open during the lifetime of a user session is a drain on resources. If you want to do that you do not have to use Seam or a dialog system simply keep an open session in your servlet session and use that one for all db access related stuff. But there is a reason why this approach is not used that often.
