struts-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "David Erickson" <>
Subject Strategy for out of date items through forms using hibernate?
Date Wed, 17 Dec 2003 18:05:35 GMT
Hi I am using Struts with Hibernate in a webapplication.. we are using forms
etc. The problem I am currently trying to decide how to handle is thus:

Assume user 1 loads up an object in a form and is modifying it.
Assume user 2 loads up the same object in a form and is also modifying it.
User 1 submits the modified object.
User 2 also submits the object, however his is out of date and I would like
the webapp to tell him that and show the differences that exist.

What is the best way to use hibernate to deal with this? What I have
attempted is using the built in timestamp feature in MySQL, I have a field
in my object that is timestamp but does not insert or update, thus mysql
controls its value. Then when the user submits the object I loaded another
copy of that object from the DB and tried to compare their dates.. however
this gave me an error saying:

net.sf.hibernate.NonUniqueObjectException: a different object with the same
identifier value was already associated with the session: 1, of class:

because of the object I loaded to compare.

What do do? Is there a better strategy for tackling this? I tried using the
actual <timestamp> in the properties for my object, but then when I tried to
submit the object the generated sql said "when id=? AND timestamp=?" meaning
it would not update if the timestamp is different, and I'm unsure if I could
even determine if it did or did not update.

Thanks in advance,

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message