Re: How do you inject a JPA EntityManager(Factory) using JSF on Tomcat?
Lew wrote:
- Generally how would one configure a web application to use JPA by resource
injection?
EricF wrote:
An EJB3 container injects the persistence unit and persistence context. Tomcat
does not provide an EJB3 container. You need to use an app server
(JBoss/Glassfish, ...), add an EJB container to Tomcat, use Spring, or get the
EntityManagerFactory yourself without injection.
Actually, adding just the OpenJPA libraries, and the Hibernate libs should
work equivalently, gets me most of the way there.
If you are using Glassfish, you should be able to get the JPA injection
working. But I don't think it will work with a web application - the web app
does not have an EJB3 container. It should work with a session bean.
I am pretty sure that EJB3 annotations will work in the right container even
if the thing isn't otherwise identified as a session bean. I haven't
experimented with that yet so I'll let you know when I do. Currently I can't
even get the darned thing to deploy to Glassfish, though it deploys to Tomcat
just fine.
You might want to take a look at the JBoss Seam project. It's a JSF framework
that works with Hibernate and EJB3. It's on my short list. :-)
It's on my list now, too.
I found that if I instantiate the EntityManagerFactory explicitly with the
name of the persistence unit, rather than rely on the annotation, that it
picks up the configuration from the persistence.xml and context.xml files just
as I'd hoped, even under Tomcat. I cannot use the Java Transaction API (JTA)
to achieve container-managed transactions, but otherwise I get the notational
convenience and instant-on access to the database for which I'd hoped.
Transaction management undoubtedly will be the next difference, but I'm
accustomed to managing transactions anyway. Making entities with @Entity is
slick as anything.
--
Lew