Any session or MDBs can use either container managed transaction (CMT) demarcation or BMT . 2.0 Entity beans must use only CMT. Persistence has nothing to do with transactions, these are totally different areas. Only the implementation has some kind of similarity. Both CMP and CMT are used thru deployment descriptor elements, whereas BMP uses progarmming thru JDBC and BMT uses programming thru javax.transaction APIs. Thanks, Sudd
SCJP 1.4, SCWCD, SCBCD 1.3
posted 17 years ago
Thanks a lot for clarifying the concept. I'm much clearer now. I have one more question. On my book, it is stated BMT beans must not use the setRollbackOnly() and getRollbackOnly. What's the reason behind?
BMT beans (only session and MDB) call setRollbackOnly() and getStatus() method on the javax.transaction.UserTransaction, which you get from calling javax.ejb.EJBContext.getUserTransaction() method. BTM bean will get IllegalStateException if it invokes setRollbackOnly() or getRollbackOnly() directly on EJBContext. Hope this helps.
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