@EJB annotation doesn't work

Question

Hello all,
I'm new to EJB3. I use the annotation @EJB for my private fields in my stateless beans.
Could someone tell me in which cases this annotation wouldn't work?
Actually I use it in many places, but in one place it doesn't work and the declared object is null... and I don't really understand why...
many thanks.

Answer 1

Hello, and thanks for your answer.
ok,
so here is where I try to call my EJB:
package servicesFacades;
import java.util.Collection;
import javax.ejb.EJB;
import javax.ejb.Stateless;
import javax.naming.InitialContext;
import services.cyberProcedureServices.CpaManifInterface;
import util.exception.ManifException;
import models.beans.File;
import models.objects.CpaManifBean;
@Stateless
public class BdCitizenServicesImpl implements BdCitizenServices {
     // All the services this class provides pass through this cyber procedure manager.
     //@EJB
     private CpaManifInterface cpaEventManager;
     public Collection<CpaManifBean> getEventsCp(String userName)
          System.out.println("YOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO, on est dans citizenServices Man!");
          getEventManager();
          try{
          return cpaEventManager.getListeCpaManifParCitoyen(userName);
          }catch (Exception ex){
               System.out.println("Exception saisie dans citizenService" + ex);
               return null;
     }and here is my EJB declaration:
package services.cyberProcedureServices;
import java.util.*;
import javax.ejb.EJB;
import javax.ejb.Stateless;
import javax.jms.*;
import javax.jms.Queue;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import org.acegisecurity.context.SecurityContextHolder;
import org.acegisecurity.userdetails.UserDetails;
import dao.cyberProcedure.CyberProcedureDao;
import dao.event.EventDao;
import services.MnfSgdiInterface;
import services.messageServices.MnfMessageCpaInterface;
import services.payementServices.MnfPaymentInterface;
import services.payementServices.MnfPaymentManager;
import services.streetsClosingServices.MnfFermetureRueInterface;
import services.streetsClosingServices.MnfFermetureRueManager;
import services.eventServices.MnfManifestationInterface;
import services.fireWorksServices.MnfFeuArtificeInterface;
import services.fireWorksServices.MnfFeuArtificeManager;
import services.personsServices.MnfPersonneInterface;
import models.*;
import models.beans.*;
import models.objects.*;
import util.exception.ManifException;
@Stateless
//@SecurityDomain("manif")
public class CpaManifManager implements CpaManifInterface {
//     @EJB
//     private MnfPersonneManager personneMgr;
     @PersistenceContext
     protected EntityManager em;
     @EJB
     private CyberProcedureDao cpDao;
     // used to get the role
     //@EJB private SessionContext ctx;
....