KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase();

KnowledgeBuilder knowledgeBuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();

knowledgeBuilder.add(ruleResource, ResourceType.DRL);

KnowledgeBuilderErrors knowledgeBuilderErrors = knowledgeBuilder.getErrors();

if (errors.size() > 0) {

   for (KnowledgeBuilderError knowledgeBuilderError : knowledgeBuilderErrors) {

      System.out.println(knowledgeBuilderError);

   }

} else {

   knowledgeBase.addKnowledgePackages(knowledgeBuilder.getKnowledgePackages());

}