Dear all,
I am actually trying to switch from "raw" Hibernate to JPA.
I have the typical "keep the same entitymanager" during a scenario
problem. IMHO, merging huge collections of entities is a nightmare that
is not worth the cost when you deal with applications with a lot of
business logic but few users and a low load. I fully endorse the
"entitymanager per request" pattern for application having high trafic,
and so need to be stateless, replicated, etc. but it does not appear to
me to be the magic solution to all problems.
With hibernate, I historically solved it with the "open session in view"
pattern. It is ugly when evaluated according to actual standards, but it
works.
https://developer.jboss.org/wiki/OpenSessionInView
When I tried to find the equivalent for JPA, I basically found
@PersistenceContext(type=PersistenceContextType.EXTENDED)
...which could be a fit if I was using container managed datasources
When digging the Hibernate 4.3.8 jpa implementation, I noticed that when I use
application managed EntityManager-s, they are all created with
PersistenceContextType.EXTENDED, and that this attribute is finally passed to :
AbstractEntityManagerImpl base class constructor :
protected AbstractEntityManagerImpl(
EntityManagerFactoryImpl entityManagerFactory,
PersistenceContextType type, // TODO: remove as no
longer used
SynchronizationType synchronizationType,
and is just ignored. :-)
On this blog (I like good authors ;-) )
https://struberg.wordpress.com/2012/04/25/is-there-a-way-to-fix-the-jpa-entitymanager/
, I found mention of Avaje, which could be a fit if it was more of a standard.
I also fond on the net references to CODI, MyFaces Orchestra and Seam solutions to this
problem. Most of the type it was also indicated that Deltaspike is "the way to
go". An affirmation that is clearly also mine in general.
However, I did not find a ready-to-use solution in the doc
http://deltaspike.apache.org/documentation/jpa.html#_extended_persistence_contexts
I was a bit surprised, as some people stated that Seam code was to be merged in
Deltaspike not to find a turn key solution.
Did I miss / misunderstood something ?
This is not a blocking problem to me. I can just use plain hibernate or
unwrapped jpa/hibernate sessions and it will work... But I would like to
understand. :-)
Thanks in advance,
Ludovic
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