I think that all annotations other that the component defining (and
default calculation of the local interfaces) are inheritable from the
superclasses already:
4.9.2Session Bean Class
<...>
•The session bean class may have superclasses and/or superinterfaces. If
the session bean has superclasses, the business methods, lifecycle
callback interceptor methods, the timeout callback methods, the methods
implementing the optional session synchronization notifications,the Init
or ejbCreate<METHOD> methods, the Remove methods, and the methods of the
SessionBean interface, may be defined in the session bean class, or in
any of its superclasses.
-marina
Antonio Goncalves wrote:
> Something like @MappedSuperclass for EJBs would be interesting. The
> container would not instanciate the abstract EJB. In turn, all the
> "concrete" EJBs would inherit method level annotations in the
> superclass (typically @TransactionAttribute, @Asynchronous...). But
> also class level annotation (you could imagine several singletons all
> inheriting from an @AbstractEJB annotated with @Startup).
>
> What do you think ?
> Antonio
>
> On Tue, Mar 6, 2012 at 08:42, Stefan Heldt <stefan.heldt_at_holisticon.de
> <mailto:stefan.heldt_at_holisticon.de>> wrote:
>
> Marina,
>
> I think abstract EJBs are not to be instantiated by the container.
> They are just superclasses (including annotations on method level)
> for non-abstract EJBs which are to be instantiated by the
> container. Method level annotations in the superclass are the only
> advantage of abstract EJBs I can see, kind of comparable to
> MappedSuperclass in JPA. Pure superclasses can be achieved by EJBs
> inheriting from classes without any annotation.
>
> So maybe having an annotation like AbstractEJB is the better way
> to make explicit that the superclass is no real EJB and can't be
> instantiated.
>
> Regards
> Stefan!
>
> -----Ursprüngliche Nachricht-----
> Von: Marina Vatkina [mailto:marina.vatkina_at_oracle.com
> <mailto:marina.vatkina_at_oracle.com>]
> Gesendet: Dienstag, 6. März 2012 02:24
> An: jsr345-experts_at_ejb-spec.java.net
> <mailto:jsr345-experts_at_ejb-spec.java.net>
> Betreff: [jsr345-experts] Re: EJB bean not being abstract
>
> Antonio, Jean-Louis,
>
> We can't remove this restriction because it would require EJB
> container to always subclass the bean class.
>
> That said, what is the purpose of an abstract EJB? What would the
> bean provider expect to happen to its abstract methods when such
> EJB is deployed to the EJB container?
>
> thanks,
> -marina
>
> Jean-Louis MONTEIRO wrote:
> > Antonio,
> >
> > Yes, may be we can remove that restriction.
> > Out of curiosity, why not just remove the @Stateless annotation from
> > the abstract class?
> >
> > I also use Abstract classes for DAO as well, and I never got such a
> > big issue with that. Isn't it?
> >
> > Jean-Louis
> >
> >
> >
> > 2012/3/5 Antonio Goncalves <antonio.goncalves_at_gmail.com
> <mailto:antonio.goncalves_at_gmail.com>
> > <mailto:antonio.goncalves_at_gmail.com
> <mailto:antonio.goncalves_at_gmail.com>>>
> >
> > Hi all,
> >
> > Since the beginning (well, as far as I remember) EJBs bean cannot
> > be abstract :
> >
> > /4.9.2 - Session Bean Class/
> > /The following are the requirements for the session bean class:/
> >
> > * /The class must be defined as public, must not be final, and
> > must not be abstract. The class must be a top level class./
> >
> >
> > That's fine, I've always live with that. But at the moment I'm
> > working on migrating a Spring application to Java EE 6. This
> > project has very clever abstract Spring services and abstract
> > Spring repositorie (DAOs). All services inherit from these ones.
> > One guy (who doesn't know much EJBs) naturally turned them into
> > abstract EJBs (abstract classes annotated with @Stateless). I was
> > amazed to see that it was working on JBoss (but not on GlassFish).
> >
> > When I looked at this code, it made me wonder : why not having
> > abstract EJBs ? if it works on JBoss why not making it work
> > everywhere... and get closer to an OO approach ?
> >
> > Just wondering....
> >
> > Antonio
> >
> >
>
>
>
>
> --
> Antonio Goncalves
> Software architect and Java Champion
>
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