Hi,

I have been pondering about this particular issue regarding the usage of SessionPerRequest with JSF. In the SessionPerRequest pattern, a hibernate session is open and a transaction started at the beginning of the request, and the transaction is committed just before returning a response to the browse.

I have been using this pattern for a while until a couple days ago I realized that a request in JSF usually involves an action that navigates to another JSF. For example a viewCustomer.jsf could have a delete customer button, which deletes the customer and navigates to listCustomer.jsf. The sequence of action is thus:

1. Begin hibernate transaction
2 .deleteCustomerAction()
3. Deletes customer from database
4. JSF navigation to listCustomer.jsf
5. Retrieve and display customer list
6. Commit hibernate transaction

There are two distinctly independent operations within the same Httprequest. To be correct – the transaction should commit after step 3, and a new transaction should begin. If I use ‘redirect’ in JSF navigation that is what it would amount to. But what is the proper way to inject the commit without redirect?

Regards,
Yee

redirection is transparent to the ORM. the request is either forwarded or redirected based upon how you have configured faces-config.xml .

Try to commit the transaction in the 'Invoke Application' phase, not the filter. This is the phase in which your action is invoked. This way you can declaratively forward/redirect the request based upon the OUTCOME of the transaction (pretty error page or retry unit of work).

Also remember the 'render response' phase is going to be next. If you have really long value bindings, like #{custumer.order.item['foo'].name}, hibernate will do a lot of lazy loading. Put something like this in the use case you describe, 'display customer list', and you have a lot of trips to the database. So ... try to load as much as you can PRIOR to the rr phase.

Thanks Dennis.

That makes sense. Would that be classified as a hibernate pattern for JSF?

Actually I have been doing this without any noticable ill effects. Hibernate auto flushing seems to handle the situation quite well. I have also been wondering whether it makes any difference ultimately.

I find lazy loading very thorny to work with ... still pondering about this.

Regards.
Yee

maybe it's a JSF pattern for hibernate ;)

Sorry - what I meant to say is that I have been blissfully ignorant of this issue as yet I did not notice any ill effects.