I probably haven't thought about this enough yet but....
"It is best practice to avoid such use of Transactional annotations in
conjunction with EJB container managed transactions in order to avoid
possible confusion."
Why wouldn't we just want to make ANY such combination illegal? There are
some odd combinations and difficult to explain behaviours otherwise
e.g. #1 : @TransactionAttribute(MANDATORY) + @Transactional(NEVER)
e.g. #2 Exception handling - how would I reconcile:
@TransactionAttribute(REQUIRES_NEW) + @Transactional(REQUIRED,
dontRollbackOn={IllegalStateException.class})
In the case of an ISE, the CMT is required to be rolledback but the CDI
annotation is in conflict.
e.g #3.
@TransactionAttribute(REQUIRES) + @Transactional(REQUIRES_NEW)
Assume the EJB throws an ISE.
According to Table 19 in the EJB spec, "Bean method runs in the context
of the caller?s transaction. This case may happen with Required,
Mandatory, and Supports attributes."
But it is now no longer true that an EJB with
@TransactionAttribute(REQUIRES) always "runs in the context of the
caller?s transaction". In the case of an ISE does the caller receive
javax.ejb.EJBTransactionRolledbackException or EJBException?
e.g #4.
Client has no context. EJB specifies:
@TransactionAttribute(REQUIRES) + @Transactional(REQUIRES_NEW)
The text leads me to believe I'd start 2 transactions here. Is that right?
So what about just:
@Transactional(REQUIRES_NEW) on a CMT EJB?
Doesn't that have to be the same as the former case since
@TransactionAttribute(REQUIRES) is the default for CMT?
My head aches....
Regards,
Ian
From: Paul Parkinson <paul.parkinson_at_oracle.com>
To: users_at_jta-spec.java.net,
Date: 06/12/2012 22:24
Subject: [jta-spec users] rough draft of JTA 1.2 section 3.7
Transactional Annotation
Hi,
Below is a rough first run of the JTA 1.2 section 3.7 Transactional
Annotation,
http://java.net/jira/browse/JTA_SPEC-5
Thank you for any feedback as we need to close this down in the next
couple weeks.
Regards,
Paul
3.7 Transactional Annotation
The javax.transaction.Transactional annotation provides the application
the ability to control transaction boundaries on CDI managed beans, as
well as classes defined as managed beans by the Java EE
specification such as servlets, JAX-RS resource classes, and JAX-WS
service endpoints, declaratively. This provides the semantics of EJB
transaction attributes in CDI without dependencies such as RMI. This
support is implemented via an implementation of a CDI interceptor that
conducts the necessary suspending, resuming, etc. [*todo specify the
number used for the transactional interceptor, so that others can choose
to order their interceptors before or after the transactional interceptor;
coordinate with CDI for this]
By default checked exceptions do not result in the transactional
interceptor marking the transaction for rollback and instances of
RuntimeException and its subclasses do. This default behavior can be
overridden by specifying which exceptions result in the interceptor
marking the transaction for rollback. The rollbackOn element can be set
to indicate which exceptions should cause the interceptor to mark the
transaction for rollback. Conversely, the dontRollbackOn element can be
set to indicate which exceptions should do not cause the interceptor to
mark the transaction for rollback. When a class is specified for either
of these elements, the designated behavior applies to subclasses of that
class as well. If both elements are specified, dontRollbackOn takes
precedence.
The following are some example usages of rollbackOn and dontRollbackOn
elements.
- The following will override behavior for application exceptions, causing
the transaction to be marked for rollback for all application exceptions.
@Transactional(rollbackOn={Exception.class})
- The following will prevent transactions from being marked for rollback
by the interceptor when an IllegalStateException or any of its subclasses
reaches the interceptor.
@Transactional(dontRollbackOn={IllegalStateException.class})
- The following will cause the transaction to be marked for rollback for
all runtime exceptions and all SQLException types except for SQLWarning.
@Transactional(
rollbackOn={SQLException.class},
dontRollbackOn={SQLWarning.class}
)
EJB application exceptions (i.e., runtime exceptions annotated with
@ApplicationException) are treated just as any other runtime exceptions
unless otherwise specified.
When Transactional annotated managed beans are used in conjunction with
EJB container managed transactions the EJB container behavior is applied
before the bean is called. When the bean is called the CDI behavior is
applied before calling the bean's methods. It is best practice to avoid
such use of Transactional annotations in conjunction with EJB container
managed transactions in order to avoid possible confusion.
?Java Transaction API Reference? on page 30 has a full description of this
annotation
[...]
/**
* Annotation used by applications to control transaction boundaries on
CDI managed beans, as well as
* classes defined as managed beans by the Java EE specification such as
servlets, JAX-RS resource classes, and JAX-WS
* service endpoints, declaratively. This provides the semantics of EJB
transaction attributes in CDI without
* dependencies such as RMI. This support is implemented via an
implementation of a CDI interceptor that conducts the
* necessary suspending, resuming, etc. [*todo specify the number used for
the transactional interceptor, so that others
* can choose to order their interceptors before or after the
transactional interceptor; coordinate with CDI for this]
* [*open issue as to whether the "value" attribute of the "Transactional"
annotation should be binding or not]
*
* By default checked exceptions do not result in the transactional
interceptor marking the transaction for rollback
* and instances of RuntimeException and its subclasses do. This default
behavior can be overridden by specifying
* which exceptions result in the interceptor marking the transaction for
rollback. The rollbackOn element can be set
* to indicate which exceptions should cause the interceptor to mark the
transaction for rollback. Conversely, the
* dontRollbackOn element can be set to indicate which exceptions should
do not cause the interceptor to mark the
* transaction for rollback. When a class is specified for either of
these elements, the designated behavior applies
* to subclasses of that class as well. If both elements are specified,
dontRollbackOn takes precedence.
*
* EJB application exceptions (i.e., runtime exceptions annotated with
@ApplicationException) are treated just as any
* other runtime exceptions unless otherwise specified.
*
* When Transactional annotated managed beans are used in conjunction with
EJB container managed transactions the EJB
* container behavior is applied before the bean is called. When the bean
is called the CDI behavior is applied before
* calling the bean's methods. It is best practice to avoid such use of
Transactional annotations in conjunction with
* EJB container managed transactions in order to avoid possible
confusion.
*
*
* @since JTA1.2
*/
@Inherited
@InterceptorBinding
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(value = RetentionPolicy.RUNTIME)
public @interface Transactional {
TxType value() default TxType.REQUIRED;
public enum TxType {REQUIRED, REQUIRES_NEW, MANDATORY, SUPPORTS,
NOT_SUPPORTED, NEVER}
Class[] rollbackOn() default {};
Class[] dontRollbackOn() default {};
}
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