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From Alexandre Léveillé <leveille.alexan...@gmail.com>
Subject Re: problem related to reading multiple messages from the queue
Date Fri, 02 Jul 2010 12:46:29 GMT
Hi Yelei,

As I see it, your loop will read a few messages. Then, the queue will be
empty and your loop will go in the Else branch of your If. The break
statement will then break your loop as Clark said, thus effectively you will
stop receiving messages.

Hope that helps,
Alexandre


On Fri, Jul 2, 2010 at 06:58, savagre <savagre@gmail.com> wrote:

>
> Hello Clark,
>
> Thanks a lot for your reply.
> I understand that the 'receive' method only retrieves the message within
> the
> interval defined by the wait time. But the messages in the queue is really
> small, like 5 or 6 lines of text; and I already increased the wait time to
> 10 seconds (10000). When the code works, it's able to read exactly the same
> message within miliseconds.
> The only way I found to get it resolved is to restart the ActiveMQ server;
> and then the same code is able to pick up messages again.
> Do you know what could be the problem here?
>
> Yelei
>
>
>
> cobrien wrote:
> >
> > Yelei
> > If DEFAULTWAITTIME expires then you will break out of your loop and not
> > receive any messages unless you restart.
> >
> > The link below has an example of implementing a Consumer.
> >
> http://activemq.apache.org/how-should-i-implement-request-response-with-jms.html
> >
> >
> > Clark
> > PS
> > Note that the JMS API JavaDoc for the API 'receive' method says
> > "Receives the next message that arrives within the specified timeout
> > interval."
> >
> > www.ttmsolutions.com
> > ActiveMQ reference guide at
> > http://bit.ly/AMQRefGuide
> >
> >
> >
> > savagre wrote:
> >>
> >> Hello guys,
> >>
> >> I've got a strange problem related to reading multiple messages from the
> >> queue.
> >> I have the following java logic to retrieve multiple messages defined by
> >> variable "numberOfMessages":
> >>
> >> Connection qConn=qFactory.createConnection();
> >> qConn.start();
> >> Session qSession=qConn.createSession(false,
> >> QueueSession.AUTO_ACKNOWLEDGE);
> >> Destination queue=qSession.createQueue(qName);
> >> MessageConsumer qReader=qSession.createConsumer(queue);
> >> TextMessage qMessage=null;
> >> for(i=1;i<=numberOfMessages;++i){
> >>     qMessage=(TextMessage)qReader.receive(DEFAULTWAITTIME);
> >>     if(qMessage!=null){
> >>                              // add qMessage to some storage
> >>      }else{
> >>      break;
> >>     }
> >> }
> >> qReader.close();
> >> qSession.close();
> >> qConn.close();
> >>
> >> It works for a while; after that the logic is not able to retrieve any
> >> text message from the queue.
> >> The queue is not empty, but the qReader always returns null value, even
> >> after I increased reading timeout.
> >> If I restart ActiveMQ server, the above piece of code would work again.
> >> Is there anybody who knows what happened to the code? Do I need to close
> >> the MessageConsumer everytime I get a message?
> >> Thanks.
> >>
> >> Yelei
> >>
> >>
> >
> >
>
> --
> View this message in context:
> http://old.nabble.com/problem-related-to-reading-multiple-messages-from-the-queue-tp29045640p29055019.html
> Sent from the ActiveMQ - User mailing list archive at Nabble.com.
>
>


-- 
Visitez ma page du Cyclo-défi contre le cancer : www.alexandreleveille.ca

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