EJB 3.1 Dependency Injection Failed

问题

i have created a stateless session bean like this :

@WebServlet(name = "ProductController", urlPatterns = {"/ProductController"})
public class ProductController extends HttpServlet {

  @EJB
  private ProductFacadeBean productBean;
}

@Stateless
public class ProductFacadeBean extends AbstractFacade<Product> implements ProductFacadeLocalInterface {
  @PersistenceContext(unitName = "OnlineStorePU")
  private EntityManager em;

  protected EntityManager getEntityManager() {
    return em;
  }

  public ProductFacadeBean() {
    super(Product.class);
  }

}

@Local
public interface ProductFacadeLocalInterface {

  void create(Product product);

  void edit(Product product);

  void remove(Product product);

  Product find(Object id);

  List<Product> findAll();

  List<Product> findRange(int[] range);

  int count();

}


public abstract class AbstractFacade<T> {
  private Class<T> entityClass;

  public AbstractFacade(Class<T> entityClass) {
    this.entityClass = entityClass;
  }

  protected abstract EntityManager getEntityManager();

  public void create(T entity) {
    getEntityManager().persist(entity);
  }

  public void edit(T entity) {
    getEntityManager().merge(entity);
  }

  public void remove(T entity) {
    getEntityManager().remove(getEntityManager().merge(entity));
  }

  public T find(Object id) {
    return getEntityManager().find(entityClass, id);
  }

  public List<T> findAll() {
    javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
    cq.select(cq.from(entityClass));
    return getEntityManager().createQuery(cq).getResultList();
  }

  public List<T> findRange(int[] range) {
    javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
    cq.select(cq.from(entityClass));
    javax.persistence.Query q = getEntityManager().createQuery(cq);
    q.setMaxResults(range[1] - range[0]);
    q.setFirstResult(range[0]);
    return q.getResultList();
  }

  public int count() {
    javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery();
    javax.persistence.criteria.Root<T> rt = cq.from(entityClass);
    cq.select(getEntityManager().getCriteriaBuilder().count(rt));
    javax.persistence.Query q = getEntityManager().createQuery(cq);
    return ((Long) q.getSingleResult()).intValue();
  }

}

Question :

What is the error about ? How to solve it ?

javax.naming.NamingException: Lookup failed for 'java:comp/env/Controller.ProductController/productBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NamingException: Exception resolving Ejb for 'Remote ejb-ref name=Controller.ProductController/productBean,Remote 3.x interface =EJB.ProductFacadeBean,ejb-link=null,lookup=,mappedName=,jndi-name=EJB.ProductFacadeBean,refType=Session' . Actual (possibly internal) Remote JNDI name used for lookup is 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' [Root exception is javax.naming.NamingException: Lookup failed for 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NameNotFoundException: EJB.ProductFacadeBean#EJB.ProductFacadeBean not found]]]

The full exception is attached here :

HTTP Status 500 -

type Exception report

message

descriptionThe server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: PWC1392: Error instantiating servlet class Controller.ProductController

root cause

com.sun.enterprise.container.common.spi.util.InjectionException: Error creating managed object for class Controller.ProductController

root cause

com.sun.enterprise.container.common.spi.util.InjectionException: Exception attempting to inject Remote ejb-ref name=Controller.ProductController/productBean,Remote
3.x interface =EJB.ProductFacadeBean,ejb-link=null,lookup=,mappedName=,jndi-name=EJB.ProductFacadeBean,refType=Session into class Controller.ProductController

root cause

javax.naming.NamingException: Lookup failed for 'java:comp/env/Controller.ProductController/productBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NamingException: Exception resolving Ejb for 'Remote ejb-ref name=Controller.ProductController/productBean,Remote
3.x interface =EJB.ProductFacadeBean,ejb-link=null,lookup=,mappedName=,jndi-name=EJB.ProductFacadeBean,refType=Session' .  Actual (possibly internal) Remote JNDI name used for lookup is 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' [Root exception is javax.naming.NamingException: Lookup failed for 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NameNotFoundException: EJB.ProductFacadeBean#EJB.ProductFacadeBean not found]]]

root cause

javax.naming.NamingException: Exception resolving Ejb for 'Remote ejb-ref name=Controller.ProductController/productBean,Remote
3.x interface =EJB.ProductFacadeBean,ejb-link=null,lookup=,mappedName=,jndi-name=EJB.ProductFacadeBean,refType=Session' .  Actual (possibly internal) Remote JNDI name used for lookup is 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' [Root exception is javax.naming.NamingException: Lookup failed for 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NameNotFoundException: EJB.ProductFacadeBean#EJB.ProductFacadeBean not found]]

root cause

javax.naming.NamingException: Lookup failed for 'EJB.ProductFacadeBean#EJB.ProductFacadeBean' in SerialContext[myEnv={java.naming.factory.initial=com.sun.enterprise.naming.impl.SerialInitContextFactory, java.naming.factory.state=com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl, java.naming.factory.url.pkgs=com.sun.enterprise.naming} [Root exception is javax.naming.NameNotFoundException: EJB.ProductFacadeBean#EJB.ProductFacadeBean not found]

root cause

javax.naming.NameNotFoundException: EJB.ProductFacadeBean#EJB.ProductFacadeBean not found

note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 3.1 logs. GlassFish Server Open Source Edition 3.1

When i created the session for entity bean using netbeans it created the abstract facade for us ? What is the purpose ? I know facade pattern is to serve as interface to route the request ?
What is the use of ejb-jar.xml ?

All settings are default. The ejb bean is created inside java ee 6 web application rather than in another war or jar. Glassfish 3.1 server.

Please help.

Thanks.

回答1:

you must use the interface. If you use Seam Solder and CDI you can specify the exact implementation with

@Inject
@Exact(ProductFacadeBean.class)

回答2:

You need to inject the bean by refering to its interface and not to its implementation directly. Something like this ..

@EJB
private ProductFacadeLocalInterface productBean;

You can then access the bean using the interface methods that you exposed in ProductFacadeLocalInterface.

来源：https://stackoverflow.com/questions/6183670/ejb-3-1-dependency-injection-failed

标签

java

dependencies

ejb

code-injection