Java – is it not allowed to implement a single local interface by two stateless beans

ejb-3.0java

I am getting following exception when a Local Interface is implemented by two Stateless beans, in which one having normal functionality and other having some enhanced functionality in it.

java.lang.RuntimeException: could not
resolve global JNDI name for @EJB for
container UserBean: reference class:
org.app.SecurityServiceLocal ejbLink:
duplicated in Some.jar

Best Answer

Finally I came to know why I am getting this exception

I have used @EJB annotation to inject a Stateless bean into another Stateless bean Name UserBean with following code

@Stateless(name="UserBean")
@EJB(name="app/SecurityService",
        beanInterface=SecurityServiceLocal.class)
public class UserBean implements UserRemote{

}

If you check the injection details I was injecting SecurityServiceLocal, which was implemented by two Stateless bean classes name SercurityServiceBean and SecurityServiceEnhaBean. So, container is in ambiguity state to decide which bean to inject in as both are implementing same interface.

This can be resolved by specifying some more information like beanName property value in @EJB annotation. There you need to provide which stateless bean class needs to be injected by using bean name(declared at that bean level (or) in ejb-jar.xml). check the code to identify the change in the injection mapping

@Stateless(name="UserBean")
@EJB(name="app/SecurityService",
        beanInterface=SecurityServiceLocal.class,
        beanName="SecurityServiceEnha")
public class UserBean implements UserRemote{

}

Related Solutions

Java – Autowiring two beans implementing same interface – how to set default bean to autowire

I'd suggest marking the Hibernate DAO class with @Primary, i.e. (assuming you used @Repository on HibernateDeviceDao):

@Primary
@Repository
public class HibernateDeviceDao implements DeviceDao

This way it will be selected as the default autowire candididate, with no need to autowire-candidate on the other bean.

Also, rather than using @Autowired @Qualifier, I find it more elegant to use @Resource for picking specific beans, i.e.

@Resource(name="jdbcDeviceDao")
DeviceDao deviceDao;

Java – jndi binding for local and remote stateless bean

If you use EJB3.0 you may use @Localbinding / @Remotebinding in JBoss. If you use EJB 3.1, the JNDI bindings are standardized (called portable global JNDI name).
name attribute of the @Stateless/@Stateful annotation defines the name of the bean. It's default is the unqualified class name.
mappedName attribute of the @Stateless/@Stateful annotation is used to map the bean to a JNDI name. If you provide this attribute, you need to provide the mappedName attribute of the @EJB annotation in order to reference the bean. In terms of mapping:
```
@Stateless(name="Bar")       => @EJB(beanName="Bar")
@Stateless(mappedName="Foo") => @EJB(mappedName="Foo")
```

In your example, try to use:

public class RoutingServiceBean {
    ...
    @EJB(mappedName=IRemoteInterface.JNDI_NAME)
    public ILocalInterface iLocalInterface;
}

Best Answer

Related Solutions

Java – Autowiring two beans implementing same interface – how to set default bean to autowire

Java – jndi binding for local and remote stateless bean

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