About Transaction

[nusa]

Hi,

In the example under noejb, I don't see any declaration of transaction, i.e. session.beginTransaction(), transaction.commit() , or transaction.rollback().

Are they been replaced by @Begin and @End ?
Is there any relationship between @Begin and session.beginTransaction() ?

Do you have a plan to 'port' CaveatEmptor using Seam ?

Thanks.

[hookomjj]

"nusa" wrote:
Hi,

In the example under noejb, I don't see any declaration of transaction, i.e. session.beginTransaction(), transaction.commit() , or transaction.rollback().

Are they been replaced by @Begin and @End ?
Is there any relationship between @Begin and session.beginTransaction() ?

Do you have a plan to 'port' CaveatEmptor using Seam ?

Thanks.

There are plans to port caveatemptor and produce more 'tomcat' friendly demos for immediate deployment.

[nusa]

Thanks for your reply Jacob.

But what about my questions on @Begin and @End ?

[hookomjj]

"nusa" wrote:
Thanks for your reply Jacob.

But what about my questions on @Begin and @End ?

@Begin and @End are separate from User Transactions. @Begin and @End is the same as marking the begin and end of a Sub-Session scope (the way I look at it). So object that are conversation scoped, become part of the conversation that has begun, and at the time that @End is invoked, those conversation scoped objects will get cleaned up from the session.

For transaction details:
http://docs.jboss.com/seam/reference/en/html/configuration.html#d0e1597

-- Jacob

[nusa]

One thing that I don't understand is why there is no beginTransaction(), commit(), or rollback() in RegisterAction.java or HotelBookingAction when calling the persist() method.

Am I missing something ?

[gavin.king]

This example uses Seam-managed transactions (SeamExtendedManagedPersistencePhaseListener) so that one transaction spans UPDATE_MODEL_VALUES and INVOKE_APPLICATION, and a second spans RENDER_RESPONSE

[bran]

This example uses Seam-managed transactions (SeamExtendedManagedPersistencePhaseListener) so that one transaction spans UPDATE_MODEL_VALUES and INVOKE_APPLICATION, and a second spans RENDER_RESPONSE

hmm... the code shows that Seam does a begin/commit for each new request, regardless of the context, not giving programmers fine-control of transaction demarcation. What if I have a sesssion bean that takes PROPOGATION_NEVER transaction attribute, for example? I expected Seam would allow annotation based demarcation.

[gavin.king]

If you need fine-grained declarative transactions, you should of course be using EJB components, not JavaBeans components. This is mentioned in the documentation.

Of course, fine-grained transactions are usually an exceptional case, not the common case.

So Seam supports both EJB declarative container-managed transactions and request-scoped Seam-managed transactions - which are a great implementation of the OpenSessionInView pattern - or a combination of both approaches.

[nusa]

Gavin,

I would like to use Seam with Hibernate, not EJB3.
That means I have to use SeamExtendedManagedPersisteencePhaseListener. But this managed transactions only supports corse-grained transaction. If I want to use a fine-grained, I have to use EJB3.

Am I correct by saying, that if I want use a fine-grained transation, use EJB3, not Hibernate ?

[gavin.king]

Well, actually, it's easily possible to use Hibernate inside the JBoss EJB3 container. JBoss EJB3 can inject a Session instead of an EntityManager.

[gavin.king]

Or, you could use SessionFactory.getCurrentSession() in any EJB3 container, not just in JBoss EJB3.

[nusa]

Well, actually, it's easily possible to use Hibernate inside the JBoss EJB3 container. JBoss EJB3 can inject a Session instead of an EntityManager.

Gavin,

If you have a sample code, in your blog, that would be great :)

[nusa]

Or, you could use SessionFactory.getCurrentSession() in any EJB3 container, not just in JBoss EJB3.

Gavin,

Again, if you have a sample code, in your blog, that would be great :)