[rules-users] Parent ClassLoader may not be null

[Abhay B. Chaware]

Hi
I am writing a drools based app. I am getting this error when I create an instance of KnowledgeBuilder

at line,

KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();


Here is the error. Can anyone tell what does this error mean ?

java.lang.NullPointerException: Parent ClassLoader may not be null
   at java.lang.ClassLoader.<init>(ClassLoader.java:239)
   at java.lang.ClassLoader.<init>(ClassLoader.java:226)
   at org.drools.util.CompositeClassLoader.<init>(CompositeClassLoader.java:38)
   at org.drools.util.ClassLoaderUtil.getClassLoader(ClassLoaderUtil.java:27)
   at org.drools.compiler.PackageBuilderConfiguration.setClassLoader(PackageBuilderConfiguration.java:333)
   at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:165)
   at org.drools.compiler.PackageBuilderConfiguration.<init>(PackageBuilderConfiguration.java:159)
   at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:210)
   at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:143)
   at Org.drools.builder.impl.KnowledgeBuilderFactoryServiceImpl.newKnowledgeBuilder(KnowledgeBuilderFactoryS
   at org.drools.builder.KnowledgeBuilderFactory.newKnowledgeBuilder(KnowledgeBuilderFactory.java:47)
   at com.ts.DBconnector.readKnowledgeBase(DBconnector.java:125)

I also tried adding this

            Thread.currentThread().setContextClassLoader( this.getClass().getClassLoader() );

But am still getting the same error ... please help !

-abhay

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110607/8bfd202b/attachment.html