Unable to run "Hello World" Drools example in Eclipse

Answer 1

You're missing the eclipse JDT core jar in your classpath. If you are not using the Drools classpath container or if you manually created your own runtime, make sure that jar is part of your classpath or runtime directory. If you are using the Drools classpath container and generated a default runtime, and the JDT core jar is not there, make sure to use a recent version of the plugin that supports Eclipse 3.5.2. You can of course also just add the JDT core jar manually and recreate your runtime.

More info on runtimes can be found here: https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/trunk/target/docs/drools-flow/html/ch.Drools_Eclipse_IDE_Features.html#d4e1329

Kris