I created the JIRA issue: https://issues.apache.org/jira/browse/OPENJPA-758

On 30-okt-08, at 20:19, Kevin Sutter wrote:

This sounds like a bug, no? If the application is specifying user- written ValueHandlers, then doesn't OpenJPA have to use an appropriate classloader to find these application-level classes? I thought we ran into a similar
situation with other user-written plugin values.  Or, maybe I'm just
dreaming...  In any case, should a JIRA be opened for this situation?

Kevin

On Thu, Oct 30, 2008 at 1:12 PM, Michael Dick <[EMAIL PROTECTED] >wrote:

Hi Jan,

I believe installing OpenJPA as a third part persistence provider will resolve the problem. Third party persistence providers may be loaded by the application's classloader so the custom value handlers should be found.

You can find the documentation on installing a third party persistence
provider at [1]. Hopefully it has sufficient information to get you
started.
If not we can try to help.

WRT to the long term change you mentioned, I agree that we can handle it better. As a bare minimum we could try the current thread's classloader or
the entity's classloader if we can't find the class on the property's
classloader.

[1]

http://publib.boulder.ibm.com/infocenter/wasinfo/v6r1/index.jsp?topic=/com.ibm.websphere.ejbfep.multiplatform.doc/info/ae/ae/tejb_jpa3rdparty.html

Regards
-mike


On Thu, Oct 30, 2008 at 10:53 AM, Jan Dockx <[EMAIL PROTECTED]> wrote:

We are working with ValueHandlers for enterprise applications that will
be
deployed on WebSphere, currently 6.1.0.19. We believe that the current OpenJPA implementation has made a less than stellar choice in how to load
value handlers, and suggest a change. But since this is a long term
solution, we also ask for pointers on how to work around the issuefor for
our current WebSphere problem.



ValueHandlers are naturally (or so we find) specific for certain value types, that are often dependent on the semantics of your business, and
thus
are part of the application, in some way bundled in the ear you are
deploying. We do unit testing out of the container with OpenJPA 1.0.3,
and
everything works like a charm.

When we deploy on WebSphere however, nothing works. OpenJPA does not find
our value handlers.
Luckily OpenJPA is open source :-), so we found with certainty that the reason is that OpenJPA tries to load the value handler with the class
loader
that loaded the meta information for the property. The class of that
object
is part of OpenJPA, and inside WebSphere, OpenJPA is loaded with a class loader that has no access to the application code, the code in the ear.
So,
ClassNotFoundException. Bummer.

The long term solution, we believe, is not to use the classloader
associated with the meta information for the property (i.e., the OpenJPA class loader), but instead the class loader of the entity for which we
are
working (which is also reachable via the parameters of the method that
does
the loading). Using the class loader of the actual value we want to
handle
is not an option, since the value can be null. The entity however is
normally also part of the application, the ear, and cannot be null.

In the short term: how can we kick WebSphere 6.1.0.19 in a mode
(settings?
deploy as shared lib? some init code?) where the current OpenJPA
implementation in there will find our ValueHandler class?





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