7.12. Managing exceptions
JSF has a limited ability to handle exceptions. To work around this problem, Seam lets you define treatment of an exception class through annotation, or through declaration in an XML file. This combines with the EJB3-standard
@ApplicationException annotation, which specifies whether the exception should cause a transaction rollback.
7.12.1. Exceptions and transactions
EJB specifies well-defined rules to control whether an exception immediately marks the current transaction for rollback, when thrown by a business method of the bean. System exceptions always cause a transaction rollback. Application exceptions do not cause a rollback by default, but they will cause a rollback if
@ApplicationException(rollback=true) is specified. (An application exception is any checked exception, or any unchecked exception annotated @ApplicationException. A system exception is any unchecked exception without an @ApplicationException annotation.)
Note
Marking a transaction for rollback is not the same as actually rolling back the transaction. The exception rules say that the transaction should be marked rollback only, but it may still be active after the exception is thrown.
Seam also applies the EJB3 exception rollback rules to Seam JavaBean components.
These rules apply only in the Seam component layer. When an exception occurs outside the Seam component layer, Seam rolls back any active transaction.
