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EJB and synchronisation
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sunil s phanse
Greenhorn
Joined: Sep 17, 2002
Posts: 1
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Hello Can i call any synchronized method of a class from an EJB. We r facing a problem wherein we are calling 1 synchronized method from onMessage() of MDB. We are trying to use the 3rd party Java classes available for connection pool. They have implimented this in java class inside synchronized method/block. When we call this from EJB we face problems. Is there any solution to this other than doing everything inside EJB  [ December 05, 2003: Message edited by: sunil s phanse ]
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Kyle Brown
author
Ranch Hand
Joined: Aug 10, 2001
Posts: 3879
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What kind of "problems" do you face? What is happening? The EJB spec forbids you to make EJB methods synchronized, but it's generally OK to call a synchronized method in a helper class... Kyle
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Kyle Brown, Author of Persistence in the Enterprise and Enterprise Java Programming with IBM Websphere, 2nd Edition
See my homepage at http://www.kyle-brown.com/ for other WebSphere information.
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Pradeep bhatt
Ranch Hand
Joined: Feb 27, 2002
Posts: 8876
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but it's generally OK to call a synchronized method in a helper class...
That is a violation as well,isn't?
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Groovy
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Kyle Brown
author
Ranch Hand
Joined: Aug 10, 2001
Posts: 3879
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Well, it's a bit of a grey area. Section 24.1.2 of the EJB 2.0 spec says "� An enterprise Bean must not use thread synchronization primitives to synchronize execution of multiple instances. Same reason as above. Synchronization would not work if the EJB Container distributed enterprise bean�s instances across multiple JVMs." This is the only statement about synchronization primitives in the spec that I know of. In fact, the usual test for this is to make sure that none of the EJB methods themselves implement synchronized, no vendor that I know of will check the call trees descending from the bean. Kyle
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Pradeep bhatt
Ranch Hand
Joined: Feb 27, 2002
Posts: 8876
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Kyle, Thanks. How is your Websphere book writing going on ? Does IBM plan to come out with any Webservices certifications?
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Kyle Brown
author
Ranch Hand
Joined: Aug 10, 2001
Posts: 3879
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Hi Pradeep. The WebSphere book should be released on December 17! As for Web Services certifications, I know some are in the pipeline but aren't aware of any dates. You may want to ask Howard Kushner -- his company is usually deeply involved in writing the tests and certification guides. Kyle
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Pradeep bhatt
Ranch Hand
Joined: Feb 27, 2002
Posts: 8876
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Originally posted by Kyle Brown: Hi Pradeep. The WebSphere book should be released on December 17! As for Web Services certifications, I know some are in the pipeline but aren't aware of any dates. You may want to ask Howard Kushner -- his company is usually deeply involved in writing the tests and certification guides. Kyle
Are you planning for any book promotion ? How do I contact Howard Kushner ?
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Kyle Brown
author
Ranch Hand
Joined: Aug 10, 2001
Posts: 3879
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My book will be featured on JavaRanch the week of January 20th. Howard hangs around here -- do a search for his name, then PM him. Kyle
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Pradeep bhatt
Ranch Hand
Joined: Feb 27, 2002
Posts: 8876
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I have sent a PM to Howard. Thanks
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subject: EJB and synchronisation
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