Good day everyone: Sorry if this is a too basic question. I'm having a recurrent problem on my rules and I still don't know how to really solve it, I searched here at the forum but I'm not so sure that the solutions proposed would work for my use case. I have to call many different methods on the LHS of some of my rules so I insert a global 'utils' object and I make my calls within eval() blocks, like this: $myObj1: ClassX (eval(globalUtil.reSupplyNeeded(amount) )) Everything works fine for now. I wrapped all my util methods within try catch blocks to avoid screwing up my stateful session (in my use case, is CRITICAL to keep the session alive). So, if an exception is thrown, I return false or true depending on the method. My main problem is with evals where I do comparisons like this one: eval($myObj1.doSomething()==$myObj2.doSomething()) I have many of these and some times I get an annoying NPE. I know I could add !=null comparisons but my rules would grow considerably. eval is extremely useful so I was wondering if I can call it from my utility class, something like this: On my Drl file: rule "eval called from here and utility class" when $someObj1 : ClassX() $someObj2 : ClassY() $myObj : Class1( eval( globalUtil.doEval($someObj1.doSomething()==$someObj2.doSomething() ) ) ) then ...bla bla bla end On my Utility Class public boolean doEval(ClassIDontKnow argument){ try{ //I don't know if this even exists, just asking if it's possible return Drools.eval(argument); } catch(Exception e){ logger.error("Something bad happened!!"); return false; } } Is something like this even possible?? , if not, other approach that you would recommend me?? Thanks a lot in advance :-) -- View this message in context: http://drools.46999.n3.nabble.com/eval-call-from-java-code-tp4018398.html Sent from the Drools: User forum mailing list archive at Nabble.com.