RE: Non-destructive listener?

> From: Nicolaus.Bauman-SWCg6hSX5lit/[email protected]
> 
> I totally agree, my needs are much better suited for topics. 
> Alas, I don't have that choice.
> 
> One last question: the approach you describe works because 
> while the browser scans for a message on the queue, it locks 
> the messages until the scan is complete. Is that a correct 
> assumption? If so, then, yeah, that does sound VERY 
> resource-intensive. 
> 
> Thanks so much for such a clear and succinct response.

The browser doesn't lock the queue. The approach works because
the browser is used to scan the queue, and individual messages are 
subsequently synchronously consumed using a QueueReceiver. 

E.g, suppose the queue contains messages A, B, and C.
Using a queue browser, you determine you want to consume message B.
So you construct a QueueReceiver with a selector:
  "JMSMessageID='" + B.getJMSMessageID() + "'"
and consume the message using the receive() method.
That leaves messages A and C in the queue.
If message D is subsequently added to the queue, a subsequent
scan with a browser will see messages, A, C, and D.

Its resource intensive in that you need to continuously scan the queue
to pick up new messages.

-Tim





-------------------------------------------------------
SF.Net email is sponsored by:
Tame your development challenges with Apache's Geronimo App Server. Download
it for free - -and be entered to win a 42" plasma tv or your very own
Sony(tm)PSP.  Click here to play: http://sourceforge.net/geronimo.php