concurrent access?

Which of the following do NOT support concurrent access?
A. Stateful session beans
B. Stateless session beans
C. Entity beans
D. Message-driven beans
a and b,
right?

Seems A,B,D. Only Entity beans supports concurrent access.
But why choose 2 answer?

IMHO, any beans that supports reentrant to be set to true allows concurrent access.

Answers are
A. Stateful session beans
B. Stateless session beans

I think IMHO it should be ABD because all three Entity, Session and MDB does not support reentrant hence cannot be concurrently accessed.
regards

I think IMHO it should be ABD because all three Entity, Session and MDB does not support reentrant hence cannot be concurrently accessed.

Entity beans can be reentrant. IN MDB reentrant does not make sense because client cannot directly invoke the bean but the container does and container makes sure that no more than one request is made to a bean.

Originally posted by Pradeep Bhat:

Entity beans can be reentrant. IN MDB reentrant does not make sense because client cannot directly invoke the bean but the container does and container makes sure that no more than one request is made to a bean.

Just a note on the SLSB: IMHO reentrant SLSB is an oxymoron, since the container can use only one SLSB per business method call.

Dragan
[ August 29, 2003: Message edited by: Dragan Milic ]

Dragan SLSB cannot be reentrant.

Originally posted by Pradeep Bhat:
Dragan SLSB cannot be reentrant.

Hi,
as usually i did NOT read carefully the question (especially the NOT part of it

). So, forget what I said

Dragan

Sorry, I mean to say SFSB, SLSB and MDB not entity bean. Just notice that

therefore, I think that (IMHO) the answer should be ABD
[ August 29, 2003: Message edited by: rastin purr ]
[ August 29, 2003: Message edited by: rastin purr ]

D is also the answer. MDB concurrently processes JMS messages but the does not allow concurrent access. The EJB container ensures that an MDB instance processes only one JMS message at a time.
[ September 02, 2003: Message edited by: Pradeep Bhat ]

I always monitor your posts!

Just kidding!

Originally posted by Dragan Milic:

Hi,
as usually i did NOT read carefully the question (especially the NOT part of it ). So, forget what I said

Dragan

Regarding Entity beans: I understand that concurrent access is allowed to entity object, and not entity instance, right? So if we are talking about entity instance the answer includes C too? Is that right?
Thanks,