I'm trying to create new objects from within a PostUpdateEventListener. The issue is that the new Object being saved, does indeed make it's way to a AbstractSaveEventListener, but the SQL is never generated and sent to the database until another statement forces a flush.

I tried setting

<prop key="hibernate.transaction.flush_before_completion">true</prop>

but doing that alone does not ever generate and send the SQL. I need to explicitly do a Session.find() or something of the sort.

Is saving a new object inside of an EventListener a big NoNo? If so, what is the recommended best practice?

(see below for sample )
-------------------------- Something Like This ------------------------------------------
public class ChangeLogListener implements PostUpdateEventListener {
public void onPostUpdate(PostUpdateEvent event) {
MappedObject newObj = new MappedObject();
event.getSession().save( newObj );
}
}

Instead of calling event.getSession().save( o ) to save the new object, call saveNewObjectFromWithinEventListener( o ) as implemented below. It will obtain the SessionFactory from the current Session and open a new Session on top of the same connection - this new Session can safely be flushed. This mechanism works fine with Transactions, specifically when using the JDBC transactions as managed with Spring's HibernateTransactionManger.

[/code]

Hi

have you managed to do the same thing with Hibernate 3.1.2?

PostUpdateEvent does not have a getSession() method anymore...

How did you manage?

Many thanks

Benoit

Benoit, I'm not currently working on the project that I wrote that snippet of code for, so I haven't had to maintain it across releases of Hibernate.

Are you using Spring with Hibernate? If so, I would recommend trying to wire the SessionFactory to the EventListener using Spring IoC. Then it can just call getSession() on that SessionFactory rather than on the PostUpdateEvent.

Hopefully doing so won't result in any sort of chicken and the egg configuration issues.

If you're not using Spring, then I guess you can do the same thing in code rather than declaratively.

LMK if you need more help or suggestions.

Hi darren

Thanks for your reply.

I am using JBoss and was hoping that the event would be able to give me the session in which it happened (as it used in 3.0.5) but it looks like I will have to go the SessionFactory (JNDI call) and ask for the getCurrentSession()...

Seems to be more convoluted and less efficient but there must be a good reason.

Thanks!

Benoit

Cool - will you be sure to post your solution so this thread is current ( at least for JBoss using JNDI ...)

Thanks to you, too.

Sure...

Here is a solution that works:



Hope this helps.

Benoit

PS: any rating welcome!!

Is this really working for somebody ? If i try this solution in Jboss 4.0.5 EJB3 RC9 inside a post-update-listener, my fresh created Entity will never get persisted in the database when i invoke

Yes i checked, my update-listener is really invoked within jboss, factory is bound and found in jndi - only the persist does nothing, not even an exception.

It seems that i have to explicitly flush()the session, then the entity gets persisted out of the listener