Statful Bean and Interface

[enda]

I have a question about current state of session beans in Seam 2.0.3.CR1

Q1:

• Does stateless bean have to implement interface that has @Local annotation?

1. Example DVD store ShoppingCart does not have @Local


2. Example SeamBay AuctionAction does not have an interface

• When I am supposet to you it? Isn't it EJB requirement?

Q2:

• When to implement serializable?

1. Example SeamBay AuctionAction does


2. Example DVD store EditCustomerAction does not

• I guess this should be implemented everytime in session bean (and attached objects)?

Q3:

• Why I ask?

1. Time to time I get serialization exception connected with EJBclass eaeea-23ea.... not found.

• This might be because I might call new XXXAction() instead of calling Component.getInstance() (I guess you create a proxy?)

1. @Remove annotation has problems sometimes too

I just want to clarify these things because I am completely sure about them. I would also put this in the documentation I have tried to find it there but unsuccessfully.

Thank you Tomas

[graben]

Here some short answers for your questions:

Q1:

Does stateless bean have to implement interface that has @Local annotation?

Yes, of course. Since your are using EJB 3.0 you need for every SLSB and SFSB a @Local or @Remote annotated interface. This will change in the future with EJB 3.1 and so called LocalBeans.

If @Local is missed in the seam examples this must be a bug!

Q2:

When to implement serializable?

The Serializeable Interface should be implemented for every SESSION, CONVERSTAION and PAGE scoped seam component that is not a EJB. EJBs are serializable by defaults since they are proxied. But you'll get warnings from the seam core!

Q3:

Why I ask?

Hard to answer. But I think that should be a problem between conversation handling and stateful bean session handling. The EJB seems to get removed earlier than the conversation. That causes that the conversation tries to work on a bean that doesn't exist anymore.

Hope that helps!