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JavaRanch » Java Forums » Certification » EJB Certification (SCBCD/OCPJBCD)
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acknowledgement mode

Christophe Verré
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Joined: Nov 24, 2005
Posts: 14687
    
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I don't get the point of acknowledgement mode for message driven beans (Auto-acknowledge, Dups-ok-acknowledge). Is this part of the exam objectives ?


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Celinio Fernandes
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Joined: Jun 28, 2003
Posts: 547

I am not sure it is on the exam, has anyone seen a question related to message acknowledgment ?

Anyways, to answer your question:

Auto-acknowledge : tells the container that it should send an acknowledgment to the JMS provider soon after the message is given to an MDB instance to process
Dups-ok-acknowledge : tells the container that it doesn't have to send the acknowledgment immediately

So the bottom line is that auto-acknowledge will not send duplicate messages while dups-ok-acknowledge might send a message that has already been sent.


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vidya sagar
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Joined: Mar 02, 2005
Posts: 580
Is this part of the exam objectives ?


Yes
 
 
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