Originally posted by Larr Goneg:
Ok, I found this post is helpful
https://coderanch.com/t/151338/java-Architect-SCEA/certification/Transactions-guarantee
but still didn't get a clear understanding! Some one kind enough to show some light for me?
I agree with Andrew Perepelytsya's analysis (May23).
I think the point that you might have been
looking to clarify is this:
Within your (J2EE) Transaction, you will make some kind of
synchronous call to an external system, which in turn
probably performs its own transaction.
Your "J2EE" application's Transaction does not need to
have any awareness that some other transaction was being
performed. To you, its just some atomic operation that
either succeeds or fails. Failure = either it returns some
"failure" or refusal message, or it throws an unpleasant
exception. Because of this atomicity requirement, your call to the
external system must be synchronous (not via async messaging, say).
So, my take is that the EJB spec's "silence" on the point about
nesting transactions is just fine as is.
Juan Rolando Prieur-Reza, M.S., LSSBB, SCEA, SCBCD, SCWCD, SCJP/1.6, IBM OOAD, SCSA