QueueReceiver.receive(long timeout) and large messages

Question

Hi ...
Our JMS application is using receive(milliseconds). I've been trying to research the exact behavior of the receive() method with a millisecond timeout, but haven't yet found out what happens if:
I specify receive (25000), i.e., timeout interval of 25 seconds;
At the 21-second mark, the response begins to arrive from the application server;
The response payload is quite large, and it takes 10 seconds for it to be completely transmitted down the network.
What happens at second number 25? Either MQ will see that the message is arriving and will wait the extra few seconds to assemble the whole thing and provide it as the return value from my receive(t) method, OR MQ will time me out, regardless.
Anybody know what's going on under the hood?
Thanks in advance!
John Taylor

Answer 1

This of course depends on the provider, but my guess is that most implementations don't "see" the message until it has arrived fully. In your case, this means that the message won't be available from the receive method until after 31 seconds. Rather than trying to time this, you may want to use the asynchronous model with a message listener.
- Bjarne.