Howto inject EJBs into POJO componets?

[amin59]

Hi,

I'm using a layerd architecture and have POJO componets as action listeners and EJBs for logic. They look like this :

@Name("listAgents")
@Interceptor(SeamInterceptor.class)
@Scope(value = CONVERSATION)
@Conversational(ifNotBegunOutcome = "main")
@Intercept(value = InterceptionType.ALWAYS)
public class ListAgentsAction {
 private static final Logger log = Logger.getLogger(ListAgentsAction.class);
 ...

And

@Name("agentFacadeBean")
@Stateless
@Interceptor(SeamInterceptor.class)
@Intercept(InterceptionType.ALWAYS)
public class AgentFacadeBean implements AgentFacade {
...

Both of them, are viewed as "Seam Componets" but when I wana inject EJBs inside my POJOs, it fails throwing this exception:

java.lang.IllegalArgumentException: could not inject: agentFacadeBean to: listAgents
 at org.jboss.seam.Component.setFieldValue(Unknown Source)
 at org.jboss.seam.Component.injectFields(Unknown Source)
 at org.jboss.seam.Component.inject(Unknown Source)
 at org.jboss.seam.interceptors.BijectionInterceptor.bijectTargetComponent(Unknown Source)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.jboss.seam.util.Reflections.invoke(Unknown Source)
 at org.jboss.seam.interceptors.Interceptor.aroundInvoke(Unknown Source)
 at org.jboss.seam.interceptors.SeamInvocationContext.proceed(Unknown Source)
 at org.jboss.seam.interceptors.ConversationInterceptor.endOrBeginLongRunningConversation(Unknown Source)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 ...

I tried to inject my EJB inside POJO action component with below code:

 @In(required = true, create = true)
 private AgentFacadeBean agentFacadeBean;

I also tried to inject via @EJB annotation but then, I get a null object.

Thanks for your help.

[drapierwim]

I've never done this before injecting sessionbeans, but my guess is that it will never work because the container must do the work for making an instance of your sessionbeans.

You should post some more complete code, it's really hard to see what exactly is going wrong.

I'm rather new to the whole J2EE stuff, so don't shoot me if I'm wrong!

[gavin.king]

It should just work. Step into the code that fails and see what is the cause of the IAE.

[amin59]

Hi,

I'm attaching this stack trace too. Maybe it can help. By the way, I commented all of my EJB's code, but problem still remains.

Caused by: java.lang.IllegalArgumentException
 at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:63)
 at java.lang.reflect.Field.set(Field.java:656)
 ... 81 more

[marius.oancea]

How about :

@In(required = true, create = true)
 private AgentFacade(deteted Bean) agentFacadeBean;

[amin59]

This is from Java API documentation. set method throws:

IllegalArgumentException - if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof), or if an unwrapping conversion fails.

[amin59]

Yes,
That was it. Well, all these new things, some times, make me forget fundamentals :)
Maybe this worths to be noted some where in docs.
Thanks a lot Marius.