No persistence manager found: lazy initialization ignored for Account

[Oliver Günther]

Hi,

I'm playing around with the addressbook tutorial.
After some rewrite and reconfiguration, I got it alive.

Server: Tomee 1.6.0.1 with Hibernate
Java: 1.7.0_u55-x64
Debian 7 / amd64

Now I wanted to see the magic of remote lazy loading. And here I'm stuck.
The client fails with NullPointerException and the Server gives a No persistence manager found: lazy initialization ignored for Account...

I've added the sample. To reproduce:
- mvn clean install the hole project tree.
- in server-ejb: tomee:run
- in client-tryout: jfx:run

Any Ideas ?

It would also be nice to have some documentation about the discovery of the EntityManager in LazyLoading. All I know is, that GraniteDs does it by itself and I cannot configure anything in an EJB environment.

Thanx,
Olli

[Oliver Günther]

Anyone ?
No Idea ?

[wdrai]

You can set the entityManagerJndiName or entityManagerFactoryJndiName in the @ServerFilter annotation (note: it's definitely missing in the docs...)

It's not sure that Tomee puts the EMF in a global JNDI by default, thus it may be also necessary to add a persistence-context-ref in web.xml.

Next your example will not work as is. Collection loading is an asynchronous operation and you have to use a callback to iterate over the elements:

for (Account account : futurResult.get().getResultList()) {

            Iterator<Box> iterator = account.getBoxes().iterator(); => does not work

}

for (Account account : futurResult.get().getResultList()) {

            ((PersistentCollection)account.getBoxes()).withInitialized(new InitializationCallback() {

                public void call(PersistentCollection boxes) {

                     Iterator<Box> iterator = boxes.iterator();

                }

            });

}

or in Java 8:

for (Account account : futurResult.get().getResultList()) {

            ((PersistentCollection)account.getBoxes()).withInitialized(boxes -> { Iterator<Box> iterator = boxes.iterator(); ... });

}

[Oliver Günther]

Hi,

thanx for the hint.
For now this is a show stopper, because Tomee doesn't seam to bind EntityManagers in the JNDI Tree. Looking into that.
But still, I have two questions:

1. Am I right to assume, that this allows only one Datasource for the hole application ?

2. I don't really get the withInitialized part you show. In documentation is written, that these are only needed if I want to manipulate the lazy loaded values. Also, if what u write is correct, wouldn't it contradict the transparent loading of entities. If I need to implement some callback for every collection I could do it without graniteds, with nearly the same effort.

Regards,
Olli