Help with simple MQ poller

[Bjorne Karlsson]

How should I implement a simple "poller"?

Basically all I want to do is to get messages off a queue.

The below code works great if there are messages on the queue. However once the queue is depleted MQQueue.get throws and exception.

I could solve it by surrounding it all in a try-catch loop and so on, but that jsut screams dirty. So how should I do a very simple minimal implementation?

Any help/links (I've searched for this extensively) would be greatly appreciated!

Thanks in advance!

//qMgr is already set up and all

int openoptions = MQC.MQOO_INPUT_AS_Q_DEF;
MQQueue queue = qMgr.accessQueue("TEST.OUT.QUEUE", openoptions);
MQGetMessageOptions gmo = new MQGetMessageOptions();
gmo.options = MQC.MQGMO_WAIT;
gmo.waitInterval = 10000;

while (true) {
	MQMessage newMsg = new MQMessage();
	queue.get(newMsg, gmo);
	String msg = newMsg.readStringOfByteLength(newMsg.getDataLength());
	System.out.println(msg);
}

[Paul Clapham]

I don't see that the queue.get method has any choice but to throw an exception once the wait time has expired. Not the way it's designed. So catch the exception.

[Steve Harney]

you could check the queue for messages before asking for one. ie

   
while (queue.getCurrentDepth()>0) {   
    MQMessage newMsg = new MQMessage();   
    queue.get(newMsg, gmo);   
    String msg = newMsg.readStringOfByteLength(newMsg.getDataLength());   
    System.out.println(msg);   
} 

[Bjorne Karlsson]

Steve Harney wrote:you could check the queue for messages before asking for one. ie

   
while (queue.getCurrentDepth()>0) {   
    MQMessage newMsg = new MQMessage();   
    queue.get(newMsg, gmo);   
    String msg = newMsg.readStringOfByteLength(newMsg.getDataLength());   
    System.out.println(msg);   
} 

This worked great! Thanks!