I am attempting to use the addJar (string) when running under Tomcat 4.1.29, but I get a null pointer exception indicating that the classloader failed to file the jar file (the call to
Thread.currentThread().getContextClassLoader().getResource(resource) appears to return null).

I know the jar file is WEB-INF/lib/ptsj.jar (cos the HibernateStrutsPlugIn comes from that jar).

Can someone indicate how to get the addJar feature to work?

From the configuration file:
<mapping jar="ptsj.jar"/>

Start of stack trace:
09-Dec-2003 16:54:30 uk.co.faststep.util.HibernateStrutsPlugIn initHibernate
SEVERE: Rethrowing exception...
java.lang.NullPointerException
at net.sf.hibernate.cfg.Configuration.addJar(Configuration.java:299)
at net.sf.hibernate.cfg.Configuration.configure(Configuration.java:846)