org.kie.internal.utils.KieHelper kieHelper = new org.kie.internal.utils.KieHelper();
kieHelper.setClassLoader(this.getClass().getClassLoader());
kieHelper.addContent( drlContent, ResourceType.DRL );

Results res = kieHelper.verify();
if ( res.hasMessages( Message.Level.ERROR ) ) {
    throw new DroolsCompilationException("Exception while compiling rule ");
}

if ( kbConf == null ) {
    kbConf = KieServices.Factory.get().newKieBaseConfiguration();
}
kbConf.setOption( EqualityBehaviorOption.EQUALITY );

KieBase kieBase = kieHelper.build( kbConf );