Injecting PersistenceContext

[satish bodas]

Am trying to inject a persistenceContext in Jboss deployed app

However I keep getting a null pointer exception - the PersistenceContext is not being injected .

Am trying to inject the PC in a non ejb object

Would this be the cause ?

Can it only be injected in ejbs ?

Thanks ,
~satish

[Jaikiran Pai]

Which version of JBoss?

[satish bodas]

using Jboss 4.2.2 GA

Thanks ,
~satish

[satish bodas]

On deploying a session bean ( stateless ) and then injecting a PersistenceContext in the session bean works for me .


So to inject PC is it only possible when using Session beans ?

If yes - than how do I make use of a container managed Entity Manager minus the injection ?

Thanks ,
~satish

[Jaikiran Pai]

The @PersistenceContext injection is only supported in managed objects (EJBs, servlets etc...). Where are you injecting this PersistenceContext? In JBoss-4.2.x the injection of PersistenceContext is probably not supported in web tier too (because 4.2.x is a J2EE1.4 server with EJB3 patch).

If yes - than how do I make use of a container managed Entity Manager minus the injection ?

A JNDI lookup will give you the persistence context. See "3.4.2. Referencing from Global JNDI" at EntityManager configuration in JBoss

[satish bodas]

Thanks Jaikiran for the inputs .

In my sample test that I am doing - I am invoking a jsp from browser

The jsp is creating an instance of a simple Java Class that I call as the "delegate" .
The delegate is being injected with the PC

I know this is not good design where JSP is starting the invocation - but I just wanted to play around with ejb's

Since my " delegate " is not managed - it too cannot make use of DI ?

Here is the sample code used :
This is the JSP

UserDelegate ud = new UserDelegate();
ud.createUser();  

This is the "delegate" :

    
public class UserDelegate {
 
@PersistenceContext(unitName = "userDatabase")
protected EntityManager entityManager;
 
public User createUser(){
User user = null;
try{
user = new User();
user.setName("shukrawar peth pune");
getEntityManager().persist(user);
}catch (Exception e) {
e.printStackTrace();
}
return user;
}

Thanks Jai for the inputs and help.
~satish

[Jaikiran Pai]

Since my " delegate " is not managed - it too cannot make use of DI ?

The application server will not scan this class since its not managed. So yes, you cannot inject it here.

[satish bodas]

Thanks Jaikiran for helping me out .

Regards,
~satish