It is called detachment, i.e. an instance that represents persistent data is read in one transaction, detached from it and then attached to another (updating) transaction. It is not possible in CMP.
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Peter Luttrell > Sent: Thursday, January 15, 2004 7:21 PM > To: [EMAIL PROTECTED] > Subject: [JBoss-user] EnityBeans: Optimistic Locking Help > > > Can JBoss handle cmp optimistic locking that spans web requests? > > Here's the scenario that i'm trying to get working: Open two > browser windows and display a value for a sample field. > Update the value on one. > Then update the value on the second, without refreshing > first, and i'm hoping to get an exception signifying the > stale data displayed, but i don't the update works fine. If > this is possible, how do i make this happen? > > I have constructed a very simple sample project based on the > optimistic locking section in the paydocs and have tried all > but the UID method of locking but can't seam to get it to > work. I'm wondering if someone might be able to identify what > i have wrong. > > The sample project can be downloaded here: > http://www.sharpuniverse.com/jboss/entitybeanlocking/sample.zi > p All you'll need to is set your jboss install dir in the > build.properties then run the deploy target and go to the > "entitybeanlocking" context. > > The JSP page reads the value from the db, puts the entitybean > in the session and displays the current value to the page. On > subsequent requests it gets the entitybean out of the > session. The update servlet gets the entitybean out of the > session and updates the value. In order to get optimistic > locking working, it sounds like i need to get and set the > value from the same reference, hence why i'm putting the > entity bean reference in the session. > > The documentation refers optimistic locking working "within > the transaction", which could be my problem considering i'm > executing across multiple web requests. If this is the > problem, can anyone suggest a strategy for getting it to work. > > thanks. > .peter > > > > > ---------- > CONFIDENTIALITY NOTICE: This e-mail message, including any > attachments,is for the sole use of the intended recipient(s), > even if addressed incorrectly, and may contain confidential > and privileged information. Any unauthorized review, use, > disclosure or distribution is prohibited. If you are not the > intended recipient, please contact the sender by reply e-mail > and destroy or delete all copies of the original message and > all attachments, including deletion from the trash or > equivalent folder. Thank you. > > ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ JBoss-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-user
