LazyInitializationException explination

[deanouk]

I'm trying to get the size of a collection of entities within a web page.
I receive this error:

[LazyInitializationException] failed to lazily initialize a collection of role:

I understand this is because the hibernate session is closed after a http request, but I don't understand why or the process behind this. I also don't know how to correct this without forcing the Set to have an Eager load.

Can anyone point me in the right direction to read up on the first/give me an explination, and could anyone directly explain how to resolve the issue correctly.

Thanks!

[waynebaylor]

Are you calling size() before the transaction ends?

[deanouk]

size() is being called in a JSP page, i.e. after the http request, so presumably after the session has been closed?

[fhh]

If you want to know the size of a collection it has to be fetched. So using fetch-type eager is the best approach.

Regards

Felix