Injecting @EJB references fails?

[ljnelson]

Following the reference documentation example on how to do this sort of thing, I have attempted (obviously badly) to define a bean in one place with @Produces, and to inject that bean into a @SessionScoped object somewhere else (using @Inject).  This combination is ambiguous, somehow, in Glassfish 3.1b09.

Here is what I've done.  I'm hoping that someone on this list can easily spot my boneheaded, idiotic, thick-skulled pilot error.

I have attempted to isolate the bean definition into its own class.  Perhaps this is misguided?  Anyhow, here is the class:

public class FrobnicatorProducer {
  @Produces
  @EJB
  private Frobnicator frobnicator; // frobnicator is a stateless session bean reference
}

Then, in my session scoped object, Foobar, I've done this:

@Inject
private Frobnicator frobnicator;

This combination results in the following error:

Caused by: org.jboss.weld.exceptions.DeploymentException: WELD-001409 Injection point has ambiguous dependencies.  Injection point:  field com.foobar.Foobar.frobnicator;  Qualifiers:  [@javax.enterprise.inject.Default()]; Possible dependencies: [org.jboss.weld.bean-/usr/local/glassfish-3.1b09/glassfish/domains/domain1/applications/foobar-1.0-SNAPSHOT/foobar-fizbaw-ejb-1.0-SNAPSHOT_jar/-SessionBean-FrobnicatorBean, org.jboss.weld.bean-/usr/local/glassfish-3.1b09/glassfish/domains/domain1/applications/foobar-1.0-SNAPSHOT/foobar-war-1.0-SNAPSHOT_war/-ProducerField-com.foobar.FrobnicatorProducer.frobnicator]

It appears to me that the session bean (FrobnicatorBean) is already a candidate for injection somehow, and so the producer field version of it is thereby redundant.  If this is true, I don't see how the reference documentation example could possibly work.  Clearly it must; I know the error is mine.  But I don't know where to go from here.

Thanks,
Laird

[asiandub]

to sort out the obvious:

- if Frobnicator is a local EJB, you could skip the production process and use / inject it directly

- if Frobnicator is a remote EJB, you should provide the link to the relevant archive (from the example: @Produces @EJB(ejbLink="../their.jar#PaymentService")
)

is that of any help?

cheers,

Jan

[ljnelson]

Yes, that is of help.  I was not aware from the reference documentation (I'm sure it's in there somewhere) that one could skip the production process entirely (not so obvious after all).  Indeed that works!

Thanks,
Laird

[asiandub]

I was not aware that one could skip the production process

that's an import part of the concept. CDI is a stateful implementation of the dependency injection pattern - this means, that the CDI-container managers not only the dependencies but also the lifecycle of the managed beans.

What you're usually doing is declare the dependencies and let the container do the rest. CDI will instantiate all beans in the correct scope for you. Producer methods are for (rare) cases when you need more control about that process, like maybe joining a transaction or not.

These parts of the documentation give a good overview:

http://docs.jboss.org/weld/reference/1.0.1-Final/en-US/html/injection.html

http://docs.jboss.org/weld/reference/1.0.1-Final/en-US/html/scopescontexts.html

cheers,

Jan