Re: How do you inject a JPA EntityManager(Factory) using JSF on Tomcat?

From: (EricF)
Sat, 19 Jan 2008 07:19:29 GMT
In article <>, Lew <> wrote:

Is it possible to configure JPA to inject EntityManager or
EntityManagerFactory on Tomcat?

I'm reading

I'm not using Spring or like framework. I have Sun's JSF libs, along with
MyFaces and Tomahawk, plus Apache OpenJPA installed in the project.

I aim to use persistence annotations to declare a class's EntityManagerFactory
member, like this:

public class Foo
    @PersistenceUnit( unitName="myPersist" )
    private EntityManagerFactory emf;

or likewise for an EntityManager member:

public class Fiz
    @PersistenceContext( unitName="myPersist" )
    private EntityManager em;

NetBeans thinks it knows all about JPA, so it already helpfully created a data
source definition for my database (e.g., "jdbc/myDs") and a persistence.xml to
map it (e.g., to "myPersist").

My questions are:

- Is there a way to achieve this resource injection given a JSP / JSF
framework on Tomcat, without adding Spring or the like?

- Is Spring a solution to this? Are there others like it?

- Generally how would one configure a web application to use JPA by resource

I'm working lately on getting this to work within Glassfish, which explicitly
claims to support injecting JPA this way.

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.

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.

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. :-)



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