Re: [eclipselink-users] Eclipse RCP - EntityManagerFactory == null

[Tom Ware <tom.ware@xxxxxxxxxx>]

Hi Christian,

  I apologize if I have missed this earlier in the thread, but the most common 
reason the persistence unit cannot be found is that the correct classloader has 
not been provided at EntityManagerFactory creation time.  We need access to a 
classloader that can load META-INF/persistence.xml as a resource.

  Here's what we do in the example:

    private EntityManagerFactory getEntityManagerFactory() {
        if (emf == null) {
            HashMap properties = new HashMap();
            properties.put(PersistenceUnitProperties.CLASSLOADER, 
this.getClass().getClassLoader());
            emf = new PersistenceProvider().createEntityManagerFactory(
                    PU_NAME,
                    properties);
        }
        return emf;
    }

-Tom

Christian August Michelsen wrote:
> Tim Hollosy skrev:
> > What's the console output/logging output before the NPE? Set your
> > logging level to Finest and post it, that would help.
>
> Well after some serious head-against-hard-surface getting the logging 
> going I suddenly started getting a helpfull little piece of info.
>
> 18:16:05 ERROR (Log4JLogListener.java:67) - 
> Log4JLogListener.logging(...): Unable to create view ID 
> jpaprototypepluginview.View2:
> Exception Description: An attempt has been made to use PersistenceUnit 
> [yazcatprototype], but no bundle is available that defines that 
> persistence unit. (code 0)
> Local Exception Stack:
> Exception [EclipseLink-28027] (Eclipse Persistence Services - 1.0.2 
> (Build 20081024)): 
> org.eclipse.persistence.exceptions.EntityManagerSetupException
> Exception Description: An attempt has been made to use PersistenceUnit 
> [yazcatprototype], but no bundle is available that defines that 
> persistence unit.
>
> So basicly it can't find the persistence.xml, which sorta was on my list 
> of possible reasons. The persistence.xml is in a bundle with my 
> annotated classes. Oddly enough I have no problem importing those 
> classes into the bundle that actually tries to start the 
> EntityManagerFactory, but I guess there is some huge barn door I'm 
> overlooking.
>
> Any suggestions what I should do?