concurrency problem

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concurrency problem

concurrency problem

2005-04-08 - By Kalra, Ashwani

Back

Reply: 1 2 3 4 5 6 7 8

I am facing concurrency problem in following scenario.

All our action classes call same stateful session bean . Each action class
obtains the reference from HTTPSession object and calls one and only one
business method.

To prevent the concurrent access to this instance which occurs when user
immediately presses two links quickly in succession I am using the following
code block

execute(...) //execute methods of Action class

{

.....

.....

//Obtain the session from Request.User will always be in session here

session=request.getSession()

Synchronised(session)

{

//call ejb's business method.

}

}

However sometimes more than one thread is able to pass through, And I get
exception from Appserver. As 2 threads are not allowed for statefull Session
bean.

Can there be problem in above code. Is it ok to synchronise on session object.

Thanks & Regds
Ashwani

Ext: 1860

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<META content="MSHTML 6.00.2800.1400" name=GENERATOR></HEAD>
<BODY>
<DIV>
I am facing concurrency problem in following scenario.
 
All our action classes call same stateful session bean . Each action class

obtains the reference from HTTPSession object and calls one and only one

business method.
To prevent the concurrent access to this instance which occurs when user

immediately presses two links quickly in succession I am using the following

code block
 
execute(...) //execute methods of Action class
{
....
....
//Obtain the session from Request.User will always be in session here
session=request.getSession()
Synchronised(session)
{
//call ejb's business method.
}
 
}
However sometimes more than one thread is able to pass through, And I get

exception from Appserver. As 2 threads are not allowed for statefull Session

bean.
Can there be problem in above code. Is it ok to synchronise on session

object.</DIV>
Thanks & Regds  Ashwani
Ext: 1860
  
<DIV> </DIV></BODY></HTML>

<table><tr><td bgcolor=#ffffff>This message contains
information that may be privileged or confidential and is the property of the
Capgemini Group. It is intended only for the person to whom it is addressed. If
you are not the intended recipient, you are not authorized to read, print,
retain, copy, disseminate, distribute, or use this message or any part thereof
. If you receive this message in error, please notify the sender immediately
and delete all copies of this message. 
 
</td></tr></table>
====================================================================
Companion Site: http://www.corej2eepatterns.com
J2EE BluePrints: http://java.sun.com/blueprints/corej2eepatterns
List Archive: http://archives.java.sun.com/archives/j2eepatterns-interest.html
Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to listserv@(protected)