[hibernate-dev] unwrap (was Re: Hibernate Search 3.4 release train)
emmanuel at hibernate.org
Thu Feb 17 03:52:00 EST 2011
On Feb 16, 2011, at 6:21 PM, Scott Marlow wrote:
> Its a minor change but I would like to make a small enhancement to
> EntityManager.unwrap(). I would like to support SessionFactory in case
> I want to use it later in AS7...
I guess the alternatives are:
- entityManager.unwrap(SessionFactory.class) //not implemented
- ( (HibernateEntityManagerFactory) entityManager.getEntityManagerFactory() )
As you know, I don't feel like an EM should spit *Factories via the unwrap method. So for me option #2 is good enough.
> Is this completely silly or just mildly silly? If creating a container
> managed entity manager doesn't consume a database connection. I propose
> that its just mildly silly. If its just mildly silly, I might want to
> use the unwrap functionality to keep the AS injection code generic
> (covering injecting a PU into a Hibernate SessionFactory). Of course,
> the other silly part is the idea that I would get an EM from the PU
> (could lead to unexpected errors if something goes wrong).
I am a bit uncertain on what you want to achieve.
Do you want to create a EM that you will not use just to get the SessionFactory?
I'm not sure I like that very much and I would use option #3 to get the SessionFactory from the EMF.
Yes the code requires a cast but you depend on Hibernate classes anyway when you need a SessionFactory.
> It might be nice to have an unwrap method on the EntityManagerFactory
> for this purpose. Is that worth proposing for a future JPA release?
Yep, it's going to be added.
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