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| mk.gupta |
 Posted: Wed Aug 02, 2006 10:23 pm Post subject: need guidance on API |
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Novice
Joined: 27 Mar 2006
Posts: 13
Location: CA, US
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Dear all,
I m new to MQ series.
I have one requirement where the custom program(in java), reads the MQ queue synchronously & insert the corresponding message into a Oracle DB. On successful insertion only, it should delete the message from MQ Queue.
I want to know about which MQ based java API classes to be used for synchronous read & how to delete the message after DB updation task.
Please guide me how to acheive this.
_________________
Regrads,
Manish
manishgupta.tcs@gmail.com |
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| Vitor |
| Posted: Wed Aug 02, 2006 11:42 pm Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Everything you need to know is here:
http://publib.boulder.ibm.com/infocenter/wmqv6/v6r0/index.jsp
For your specific needs you should refer to the Application Programming Guide and the Using Java manual, which lay out all the concepts and information you need along with some samples.
MQ supports the concept of unit of work, so there's no problem with syncronising a DB insert with a queue read. You'll find the exact parameters required to request MQ does this in the manual. Likewise, a successfully commited read will automatically remove the message from the queue.
Happy reading! 
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Insanity is the best defence. |
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| mk.gupta |
| Posted: Thu Aug 03, 2006 2:32 am Post subject: |
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Novice
Joined: 27 Mar 2006
Posts: 13
Location: CA, US
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Thanks Vitor,
I started reading, Also any existing code for reference shall be very helpful.
Thanks,
Manish
_________________
Regrads,
Manish
manishgupta.tcs@gmail.com |
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| Vitor |
| Posted: Thu Aug 03, 2006 2:38 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Like I said, there's example code in the manuals. You'll find sample code for most things in with your queue manager installation; the exact location will be in the Quick Beginnings manual for your platform. On Windows it's Program Files\MQ\tools\samp, on Unix it's /var/mqm/opt/samp
Or something like those. It's in the manual anyway. 
Be aware that the samples are just that; samples to illustrate a point. They're not necessarially production quality.
Have fun
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| jefflowrey |
| Posted: Thu Aug 03, 2006 3:01 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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Also, if you need to guarantee that both the insert and the get are processed atomically, you need XA coordination (two-phase commit).
This requires some slightly different code on your part, and requires some configuration of the queue manager, and requires that your code runs with a server/bindings connection, and not as a client. This means it must run on the same machine as the queue manager.
But, as Vitor says - there's plenty of documentation and pre-supplied samples.
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| kevin_22 |
| Posted: Thu Aug 03, 2006 3:43 am Post subject: |
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Centurion
Joined: 08 Mar 2005
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| mk.gupta |
| Posted: Thu Aug 03, 2006 3:54 am Post subject: |
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Novice
Joined: 27 Mar 2006
Posts: 13
Location: CA, US
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Thanks guys,
I got the initial success as i could establish the connection with MQ server & started reading the Message with help of guides....but i couldn't get any reference (hard luck) for clearing the queue after browse.. see my code below, its reading wonderfully from queue but reading same message again & again. say I am successful in updading the DB, how can I clear the queue to read the next message, suppose in next run of program? Please gimme some clue.
Thanks,
Manish
import com.ibm.mq.*;
public class MQBrowse {
/**
* MQBrowse constructor comment.
*/
public MQBrowse() {
MQEnvironment.hostname = "localhost";
MQEnvironment.port = 1415;
MQEnvironment.channel = "SYSTEM.DEF.SVRCONN";
MQEnvironment.userID = "db2admin";
MQEnvironment.password = "P@ssw0rd123";
final String qManager ="BRKQM";
final MQQueueManager qMgr;
try{
// Create a connection to the queue manager
qMgr= new MQQueueManager(qManager);
// Set up the options on the queue we wish to open...
// Note. All MQSeries Options are prefixed with MQC in Java.
// Note: Open the queue for browsing option. (Important)
int openOptions = MQC.MQOO_BROWSE | MQC.MQGMO_LOGICAL_ORDER;
MQQueue system_default_local_queue1 = qMgr.accessQueue("Y.WXX.ORD.INPUT",
openOptions);
MQMessage retrievedMessage =new MQMessage();
// Set the get message options..
MQGetMessageOptions gmo =new MQGetMessageOptions(); // accept the defaults
// same as MQGMO_DEFAULT
gmo.options = MQC.MQGMO_WAIT | MQC.MQGMO_BROWSE_FIRST;
// get the message off the queue..
system_default_local_queue1.get(retrievedMessage,gmo);
System.out.println("Message retrieved from the queue");
// And prove we have the message by displaying the UTF message text
String msgText =retrievedMessage.readUTF();
System.out.println("The message is:"+msgText);
// Close the queue.
system_default_local_queue1.close();
// Disconnect from the queue manager.
qMgr.disconnect();
} // End of try
// If an error has occurred in the above, try to identify what went wrong.
// Was it an MQSeries error?
catch (MQException ex) {
System.out.println("An MQSeries error occurred :Completion code "+
ex.completionCode +"Reason code "+ex.reasonCode);
}
// Was it a Java buffer space error?
catch (java.io.IOException ex) {
System.out.println("An error occurred whilst writing to the message buffer: " + ex);
}
catch (Exception ex) {
System.out.println("An error occurred whilst writing to the message buffer:"+ex);
} //End of catch.
}
/**
* Insert the method's description here.
* Creation date: (31/07/2006 9:59:30 AM)
* @param args java.lang.String[]
*/
public static void main(String[] args) {
new MQBrowse();
}
}
_________________
Regrads,
Manish
manishgupta.tcs@gmail.com |
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| Vitor |
| Posted: Thu Aug 03, 2006 3:58 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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Of course it is - you've specified MQC.MQGMO_BROWSE_FIRST as an option so it's browsing the first message over and over. But why browse? A successful get removes the message from the queue in exactly the way you want.
Spend a bit more time reading, perhaps the Introduction to Messaging and Queuing, before jumping into the code. This really is very, very basic stuff. 
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| fjb_saper |
| Posted: Thu Aug 03, 2006 2:58 pm Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20696
Location: LI,NY
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And do a search on the manual on syncpoint... but if you need a multiphase commit with a DB you should really be doing it with WAS or Weblogic in JMS and use an external (WAS) J2EE transaction coordinator...
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| mk.gupta |
| Posted: Fri Aug 04, 2006 2:23 am Post subject: |
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Joined: 27 Mar 2006
Posts: 13
Location: CA, US
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