| Author |
Message
|
| michael.shapira |
 Posted: Wed Apr 04, 2007 3:16 am Post subject: MQ API to get the date of the message |
 |
|
Novice
Joined: 03 Apr 2007
Posts: 14
|
Hi All.
I am using MQ API (com.ibm.mq) to connect to the WebSphere MQ.
Lets say tat I have several messages in my queue. How can I get the datetime when the message was put to the queue without pulling it out from the queue?
Thank you |
|
| Back to top |
|
 |
| Vitor |
| Posted: Wed Apr 04, 2007 3:29 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
Browse each message in turn, retrieving the put date & put time from the message header.
The Using Java manual will guide you in the methods & options needed.
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| jefflowrey |
| Posted: Wed Apr 04, 2007 3:55 am Post subject: |
|
|
Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
|
I hope you're not writing your own monitoring solution.
The first message on the queue will be the oldest message.
The correct approach to having several messages on a queue is to process them all until there are no messages left on the queue.
_________________
I am *not* the model of the modern major general. |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:19 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| jefflowrey wrote: |
The first message on the queue will be the oldest message.
|
Unless the queue is delivering in priority sequence.
But yes, if the reason you're looking at datetime to work out which to process it's a bad design.
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| michael.shapira |
| Posted: Wed Apr 04, 2007 4:22 am Post subject: |
|
|
Novice
Joined: 03 Apr 2007
Posts: 14
|
No. I am looking for the date because the demand in my application is not to process messages with now-putDateTime<10 minutes.
Thank you all. Can you post a link on documentation about how to work and extract message header? |
|
| Back to top |
|
|
| michael.shapira |
| Posted: Wed Apr 04, 2007 4:27 am Post subject: |
|
|
Novice
Joined: 03 Apr 2007
Posts: 14
|
I found a sample code for message browsing
| Code: |
try
{
int openOption = 0;
openOption = MQC.MQOO_BROWSE | MQC.MQOO_INPUT_SHARED ; // open options for browse & share
q = manager.accessQueue("Q.TEST", openOption,null,null,null);
System.out.println( "Open queue sucessfull... ");
MQGetMessageOptions getMessageOptions = new MQGetMessageOptions();
getMessageOptions.options = MQC.MQGMO_BROWSE_FIRST;// | MQC.MQGMO_WAIT ; //for browsing
getMessageOptions.waitInterval = MQC.MQWI_UNLIMITED; // for waiting unlimted times
// waits unlimited
while(true)
{
MQMessage message = new MQMessage();
BufferedWriter writer ;
String strMsg;
try
{
System.out.println( "waiting for message ... ");
q.get(message, getMessageOptions);
System.out.println( "Get message sucessfull... ");
//message.getTotalMessageLength()
byte[] b = new byte[message.getTotalMessageLength()];
message.readFully(b);
strMsg = new String(b);
System.out.println(strMsg);
// if empty message, close the queue...
if ( strMsg.trim().equals("") )
{
System.out.println("empty message, closing the queue ...Q.TEST");
break;
}
message.clearMessage();
writer = new BufferedWriter(new FileWriter("c:\\draft\\MQ.txt", true));
writer.write ("\n");
writer.write(new String(b));
writer.write ("\n");
writer.close();
getMessageOptions.options = MQC.MQGMO_BROWSE_NEXT ;
}
catch (IOException e)
{
System.out.println("IOException during GET: " + e.getMessage());
break;
}
} // while ends here
}
catch ( MQException mqExp)
{
System.out.println("Error in opening queue ....");
//System.out.println("Queue Name : " + qName);
System.out.println("CC : " + mqExp.completionCode );
System.out.println("RC : " + mqExp.reasonCode);
}
|
but i don't see the date in the result |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:30 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| michael.shapira wrote: |
No. I am looking for the date because the demand in my application is not to process messages with now-putDateTime<10 minutes.
|
I'm always suspicious of designs that insert artificial delays.
You'll also encounter some issues if you're looping through a queue of any size looking for relevant messages in that manner, especially if new messages keep being added.
I've already mentioned the Using Java manual (or it's online equivalent).
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| jefflowrey |
| Posted: Wed Apr 04, 2007 4:32 am Post subject: |
|
|
Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
|
The put date and put time are not in the message body.
The code you showed only prints the message body.
It is a horrible idea to let messages pile up on a queue, and only process messages that are older than now - x, for any value of x greater than "0".
What is the business case behind the horrible technical requirement?
_________________
I am *not* the model of the modern major general. |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:33 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| michael.shapira wrote: |
| I don't see the date in the result |
Very few applications bother with it, for reasons alluded to earlier in the post.
You'll also need something a bit wizzier than that sample to achieve your ends, for the reasons I allude to.
The MQMD PutDate and PutTime fields are mapped onto the JMS header field JMSTimestamp.
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:35 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| Vitor wrote: |
You'll also encounter some issues |
Horrible is another valid description of this proposal..... 
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| jefflowrey |
| Posted: Wed Apr 04, 2007 4:42 am Post subject: |
|
|
Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
|
| Vitor wrote: |
| The MQMD PutDate and PutTime fields are mapped onto the JMS header field JMSTimestamp. |
The sample shown is using the base MQ API, not JMS.
_________________
I am *not* the model of the modern major general. |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:43 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| jefflowrey wrote: |
| Vitor wrote: |
| The MQMD PutDate and PutTime fields are mapped onto the JMS header field JMSTimestamp. |
The sample shown is using the base MQ API, not JMS. |
Like I said, I can get "Hello World" into a box now...  
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
| jefflowrey |
| Posted: Wed Apr 04, 2007 4:44 am Post subject: |
|
|
Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
|
| Vitor wrote: |
| Like I said, I can get "Hello World" into a box now... |
The easiest clue is that it mostly looks like a C MQ program, with MQ Options and etc.
_________________
I am *not* the model of the modern major general. |
|
| Back to top |
|
|
| michael.shapira |
| Posted: Wed Apr 04, 2007 4:54 am Post subject: |
|
|
Novice
Joined: 03 Apr 2007
Posts: 14
|
Let me correct myself. Indeed I am using MQ API.
About the bad desighn .... I am not Java programmer, I am mostly PL/SQL developer. When one use Oracle Application he can expect mostly stange issues that are mostly have even more strange solution.
I looked into Java manual. It describes the use of JMS , but I didn't find how can I get the header data with MQ API |
|
| Back to top |
|
|
| Vitor |
| Posted: Wed Apr 04, 2007 4:59 am Post subject: |
|
|
Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
|
| michael.shapira wrote: |
When one use Oracle Application he can expect mostly stange issues that are mostly have even more strange solution.
|
But this is MQ. Your design is leading you into a bad place that can cause serious problems later on.
Or it's horrible, to use the shorthand of my estemed associate.
As to the header data, I think I've already demonstrated my lack of reliable knowledge in this area so I'll pass on that question.
_________________
Honesty is the best policy.
Insanity is the best defence. |
|
| Back to top |
|
|
|
|
