| Author |
Message
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| MABeatty1978 |
 Posted: Tue Sep 22, 2015 8:52 am Post subject: Subsequent get not getting |
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Acolyte
Joined: 17 Jul 2014
Posts: 54
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I've got a java application the executes an externam process which puts several messages on a queue. It does a Process.waitFor() and when the process completes, it gets the messages
| Code: |
boolean moreMessages = true;
int mqoo = MQConstants.MQOO_INPUT_AS_Q_DEF | MQConstants.MQOO_OUTPUT | MQConstants.MQOO_INQUIRE;
MQQueue tmpQueue = qmgr.accessQueue("SYSTEM.DEFAULT.MODEL.QUEUE", mqoo, qManagerName, dynQName, null );
gmo.options = MQConstants.MQGMO_WAIT;
gmo.waitInterval = 10000;
MQMessage = new MQMessage();
while (moreMessages) {
try{
log.write("Curr depth1: " + tmpQueue.getCurrentDepth());
tmpQueue.get(msg, gmo);
log.write("Curr depth2: " + tmpQueue.getCurrentDepth());
}
catch{
if (rc = 2033){
log.write("Curr depth3: " + tmpQueue.getCurrentDepth());
log.write("No messages Available");
moreMessages = false;
}
}
} |
When I run the program I get the following:
Curr depth1: 6
Curr depth2: 5;
Curr depth1: 5
----- there is a 10 second delay -----
Curr depth3: 5
No Messages Available
What is going on here? Clearly there are still 5 more messags available, so why is it going into the Exception block with mqrc 2033?
Last edited by MABeatty1978 on Tue Sep 22, 2015 9:02 am; edited 1 time in total |
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| MABeatty1978 |
| Posted: Tue Sep 22, 2015 9:01 am Post subject: |
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Acolyte
Joined: 17 Jul 2014
Posts: 54
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It happens every time.... mess around for 4 hours trying to figure it out...
Give up and go to the boards....
Figure it out less than 2 minutes later.
Problem was that I defined my MQMessage msg outside of the while loop so msg was still populated when it got to the second iteration.
The solution was to move the MQMessage msg = new MQMessage(); into the while loop so a new message was insantiated each time around.
Though.... can someone explain why? Why didn't MQ just get the next message and over write the old one? |
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| mqjeff |
| Posted: Tue Sep 22, 2015 9:06 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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Because you were asking it to get a message with the same MsgID.
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chmod -R ugo-wx / |
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| tczielke |
| Posted: Tue Sep 22, 2015 11:17 am Post subject: |
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Guardian
Joined: 08 Jul 2010
Posts: 941
Location: Illinois, USA
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Another option is to keep the code the way it was but add this into your loop after you get the message:
| Quote: |
Arrays.fill(msg.messageId, (byte) 0);
Arrays.fill(msg.correlationId, (byte) 0);
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I write Java with a C mentality, so allocating the same object over and over again offends my programming sensibilities. 
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Working with MQ since 2010. |
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| mqjeff |
| Posted: Tue Sep 22, 2015 11:32 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| tczielke wrote: |
| I write Java with a C mentality |
You should teach that to Vitor.
 
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| tczielke |
| Posted: Tue Sep 22, 2015 11:34 am Post subject: |
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Guardian
Joined: 08 Jul 2010
Posts: 941
Location: Illinois, USA
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You should see my Java code . . . .
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Working with MQ since 2010. |
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| mqjeff |
| Posted: Tue Sep 22, 2015 11:37 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| tczielke wrote: |
| You should see my Java code . . . . |
You should see Vitor's...
I mean, if there were any...
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| Vitor |
| Posted: Tue Sep 22, 2015 12:29 pm Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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That drink I promised to buy you at MQTC - how do you take your hemlock? Straight? On the rocks?
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Honesty is the best policy.
Insanity is the best defence. |
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| fjb_saper |
| Posted: Tue Sep 22, 2015 6:51 pm Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| Vitor wrote: |
| That drink I promised to buy you at MQTC - how do you take your hemlock? Straight? On the rocks? |
On the rocks with a splash of Absinthe.... 
_________________
MQ & Broker admin |
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| mqjeff |
| Posted: Wed Sep 23, 2015 4:57 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| fjb_saper wrote: |
| Vitor wrote: |
| That drink I promised to buy you at MQTC - how do you take your hemlock? Straight? On the rocks? |
On the rocks with a splash of Absinthe.... |
 
_________________
chmod -R ugo-wx / |
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| tczielke |
| Posted: Wed Sep 23, 2015 5:01 am Post subject: |
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Guardian
Joined: 08 Jul 2010
Posts: 941
Location: Illinois, USA
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I think Socrates preferred hemlock neat . . .
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Working with MQ since 2010. |
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| mqjeff |
| Posted: Wed Sep 23, 2015 5:02 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| tczielke wrote: |
| I think Socrates preferred hemlock neat . . . |
Socrates himself was permanently pissed.
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