About Question enthuware.oce-ejbd.v6.2.495 :

[ETS User]

Could you please clarify the following for me: what happens is the method mA() catches and swallows the javax.ejb.EJBTransactionRolledbackException ?

I would assume that in this case, the transaction would be marked for rollback, the bean B would _not_ be destroyed, since it wasn't called, and the bean A would _not_ be destroyed either, since mA() completes succesfully.

Or would the client get an exception anyway?

[kezman9]

EJBException is a system exception (it extends RuntimeException) which means that containter will mark bean's A transaction for rollback. In this case client will get EJBTransactionRolledbackException as explained in answer (its transaction context which propagates to bean A has already been marked for rollback).

[sanju.ait@gmail.com]

Why "The bean B instance will be discarded." is not true.

It thrown runtime system exception, still instance is not discarded, why so?

[admin]

Did you read the explanation?

[sanju.ait@gmail.com]

Bean A could have catch system exception from bean B and handled properly instead of just propagating it to container.
In that case bean A instance won't get discarded and also state of transaction could also have been different.

[sanju.ait@gmail.com]

There is noting mentioned about exception handling, thats why this confusion.

If same thing happened in real exam, what shall we assume about such exception handling?

[admin]

You might get a question on the exam where it is not clear whether the exception is caught or not. It is really difficult to make a general rule about what to assume because it really depends on the mind of the question setter. In general, you should not assume anything that requires extra coding.

HTH,
Paul.

[ramy6_1]

Hello ,

In this case I think mA() will receive transactionrequiredexception right ?

Please confirm.

[himaiMinh]

The explanation says this about bean A:

when it calls B's method, it will get a javax.ejb.EJBException, which is a system exception.... the bean A instance will be discarded. There is no impack on bean B instance.

However, in p.370 of JSR 318, session 13.6.2.6 NEVER,

If the client calls with a transaction context, the container throws the javax.ejb.EJBException...

So, bean B cause the EJBException to be thrown. Why bean B is not discarded ?

[admin]

A Bean is discarded if a system exception is thrown out of the bean to the container. If a bean receives an exception due to some other call, it can always catch it. In this case, there is no reason for the bean to be discarded.

[himaiMinh]

So, bean B is not discarded because of these reasons:
1. when bean B is not supposed to run in any transaction context, the container throws the exception.
2. the exception is thrown by the container in step 1, not by bean B.

Bean B is not discarded.

Correct me if I am wrong.

[himaiMinh]

Regarding to this question, if the client bean has a try/catch block to handle the EJBException thrown from bean A, where the EJBException is caused by the container and the NEVER attribute of bean B,

will the client bean discarded ?

I assume if the client bean can handle any EJBException thrown from other callee bean, the client bean's transaction won't be marked for rollback and won't be discarded.

[admin]

Yes, it is the bean that throws a system exception out to the container that is discarded, not the bean that receives such an exception (if it handles the exception). Same with the transaction.

[aazizi.tarik]

Could you please say what is the exception thrown from mB()?
Like for example in case of mandatory it throws javax.ejb.TransactionRequiredException?

[admin]

mB() will not throw any exception because it will not even be invoked. The container will throw an EJBException to the caller.