Re: [drools-user] NoClassDefFoundError:org/drools/base/BaseClassFieldExtractor

[Mark Proctor]

http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/main/java/org/drools/compiler/PackageBuilderConfiguration.java This is how we determine the classloader: public PackageBuilderConfiguration() { ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); if ( classLoader == null ) { classLoader = this.getClass().getClassLoader(); } this.classLoader = classLoader; } I believe this is the normal way of doing it and to take it from the class, as default, may break other systems. Mark Nat wrote: I finally found the problem. Drools has a ClassFieldExtractorFactory that creates a classloader who's parent comes from Thread.currentThread().getContextClassLoader(). This willl cause the drools classloader to not be able to see the plugin classes. A better way to do it would have been to check both the context and the current classes classloader. Since that isn't going to happen I'll have to shift things around a bit to make it work. Nat Edson Tirelli-3 wrote: Nat, What kind of environment are you working on? Stand-alone JSE, app server JEE, etc? I'm asking because yesterday I had to fix the same issue for a JBRules Ant task and in the end it was an ant classloader that was messing with some stuff jbrules needs. So, basically, if you are sure you have all dependencies on classpath, it is probably a classloader issue. []s Edson Nat wrote: At runtime I am getting a NoClassDefFound exception for the class org.drools.base.BaseClassFieldExtractor when I try to call the method addPackageFromDrl( src) from PackageBuilder. I know the class is in drools-core.jar. I know that I can load and instansiate org.drools.RuleBaseFactory which is in the same jar file so I know the jar is in my classpath. I'm guessing BaseClassFieldExtractor needs something that is missing??? Does anyone have any ideas as to where I'm going wrong or how I can find what is missing? I know this is somewhat vague but I'm at a loss of where to look next. Thanks in advance for your time, Nat -- --- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3124-6000 Mobile: +55 11 9218-4151 JBoss, a division of Red Hat @ www.jboss.com IT executives: Red Hat still #1 for value http://www.redhat.com/promo/vendor/ --------------------------------------------------------------------- To unsubscribe from this list please visit: http://xircles.codehaus.org/manage_email