Clebert,
On 12/02/2013 21:54, Clebert Suconic wrote:
> Hey I have a quick question.. this seems an inconsistency:
> on XAConnection, a createSession is supposed to return a Connection
>
> http://docs.oracle.com/javaee/6/api/javax/jms/XAConnection.html#createSession(boolean,%20int)
>
> While on a QueueConnection a createSession is supposed to return a XAConnection
> http://docs.oracle.com/javaee/1.3/api/javax/jms/XAQueueConnection.html#createQueueSession(boolean,%20int)
>
> Is that a typo on the spec? from what I have seen around users are expecting the super class to be respected an not have
> the semantic changing by just getting an XAConnection or XQueueConnection.
>
> We are doing a new release of HornetQ and I was reviewing our implementation when I bumped into this. that seems a
> typo to me.
Good question. The problem methods are on XAQueueConnection
/** Creates an {_at_code XAQueueSession} object.
*
* @param transacted usage undefined
* @param acknowledgeMode usage undefined
*
* @return a newly created {_at_code XAQueueSession}
*
* @exception JMSException if the {_at_code XAQueueConnection} object
* fails to create an XA queue session due to some
* internal error.
*/
QueueSession
createQueueSession(boolean transacted,
int acknowledgeMode) throws JMSException;
and on XATopicConnection
/** Creates an {_at_code XATopicSession} object.
*
* @param transacted usage undefined
* @param acknowledgeMode usage undefined
*
* @return a newly created XA topic session
*
* @exception JMSException if the {_at_code XATopicConnection} object
* fails to create an XA topic session due to some
* internal error.
*/
TopicSession
createTopicSession(boolean transacted,
int acknowledgeMode) throws JMSException;
I agree that this looks like a typo, especially since they are inconsistent with the API docs for XAConnection . If the
method signature returns a QueueSession (or TopicSession) that it makes no sense at all for the javadoc comment to say
that it creates a XAQueueSession (or XATopicSession), especially when there are alternative methods to return a
XAQueueSession (or XATopicSession).
I've logged this as
http://java.net/jira/browse/JMS_SPEC-114
I think we can correct this for JMS 2.0
That said, the spec doesn't explain why two separate methods are provided here.
Neither method is intended for direct application use: the javadoc comment for XAConnection states that it is "for use
by JMS providers to support transactional environments. Client programs are strongly encouraged to use the transactional
support available in their environment, rather than use these XA interfaces directly."
We still have
http://java.net/jira/browse/JMS_SPEC-26 open to discuss the future of these interfaces (and perhaps
clarify how they are supposed to be used), which we will revisit for JMS 2.1.
Any other views?
Nigel