Transactions and security - EJB 3 in Action - page 233

logger.log(Level.SEVERE,"An error ocurred processing the order.",ce);
context.setRollbackOnly();
}
...
}
As this snippet shows, calling setRollbackOnly on javax.ejb.EJBContext
marks the transaction for rollback when there's an error processing the credit card. If you
didn't mark the transaction for rollback, then any changes made would actually be commit-
ted. This is an important point to remember—it's your responsibility to tell the container
what to do in the event of an application exception.
The setRollbackOnly method on the EJBContext can only be used in methods that
have a transaction attribute type of REQUIRED , REQUIRED_NEW , or MANDATORY . If a
transaction hasn't been started, as in the case of SUPPORTED or NEVER , a java.lang
.IllegalStateException will be thrown.
As we stated earlier, when a transaction is marked for rollback, the transaction doesn't
immediately end. The method doesn't return when the transaction is marked for rollback.
Instead, the method will continue as if nothing happened. The EJBContext provides a
method that enables you to determine whether a transaction has been marked for rollback:
getRollbackOnly() . Using this method, you can then decide whether you want to en-
gage in a long-running operation that isn't going to be persisted. You could tweak the code
from listing 6.1 to skip closing a bid if the chargeCreditCard operation fails:
public void placeSnagItOrder(Item item, Bidder bidder, CreditCard card) {
try {
if(!hasBids(item)) {
creditCardManager.chargeCreditCard(card,item.getInitialPrice());
if(!context.getRollbackOnly()) {
closeBid(item,bidder,item.getInitialPrice());
}
}
Note
The setRollbackOnly and getRollbackOnly methods can only be invoked in
an EJB using CMT with these transaction attributes: REQUIRED , REQUIRES_NEW , or
MANDATORY . Otherwise, the container will throw an IllegalStateException .