[jdom-interest] using JDOM in IBM Websphere Application Server 4.0.5

[Sullivan, Sean C - MWT]

I am using the JDOM "b8" release in a J2EE web application.

My application runs in IBM Websphere Application Server 4.0.5

Here's what I have in my EAR file:

       foobar.ear/foobar.war/WEB-INF/lib/jdom.jar 

When I tried using the application, I observed a nasty error:

	java.lang.NoSuchMethodError


I discovered that this error was caused by a classloader / library conflict.

IBM Websphere 4.0.5 provides a copy of the JDOM library.  IBM 
distributes version "b7" of jdom.jar

You'll find JDOM here:

	$WAS4_HOME/lib/jdom.jar


To resolve the library conflict, we decided to set the following JVM 
system properties:

1) com.ibm.ws.classloader.J2EEApplicationMode=true
2) com.ibm.ws.classloader.warDelegationMode=false

Websphere's classloader architecture is described here:

http://www-3.ibm.com/software/webservers/appserv/doc/v40/ae/infocenter/was/r
nmodule.html

http://www-3.ibm.com/software/webservers/appserv/doc/v40/ae/infocenter/was/r
nclassholders.html

Cheers,

-Sean