Inheritance is outside the scope of the current EJB specification (it's a real shame
since inheritance is a very natural object-oriented feature...). The official reason
is that the mapping of primary keys with inheritance could become quite complex.
However, O/R mapping tools have mapped inheritance for a long time.
As a result, some EJB products have proprietary support of inheritance.
We, at France Telecom R&D, are working on a persistence middleware called JORM which
will allow inheritance (among other features). We have an internal first version of
JORM which we are currently integrating with the open-source JOnAS EJB server
(http://www.objectweb.org/jonas).
We'll send messages on the list when JORM becomes available.
alex
"Rhodes, Phillip C." wrote:
> I am trying to use an object model from Java Modeling in Color with URL by
> Peter Coad, Eric Lefebvre and Jeff DeLuca.
> In particular, there is a abstract Payment class that is extended by
> CreditCardPayment and EFTPayment...
>
> How would this map to EJB? CreditCardPayment and EFTPayment would be
> persisted in my database, so they would be Entity Beans. But there are
> fields and methods defined in Payment superclass that I would like to use.
> Yet I probably have to make Payment in an entity bean also to persist its
> fields to the database.
>
> I would really appreciate your thoughts on this.
> Thanks.
>
> Phillip Rhodes
> [EMAIL PROTECTED]
> Alcoa eCommerce
> https://www.ALCOADIRECT.COM
> 826B Two Allegheny Center Pittsburgh, PA 15212
> (412) 553-4900 (phone) (412) 553-2484 (fax)
>
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