If you want to stop execution you can do

kcontext.getKnowledgeRuntime().halt();

 

However this will only get executed once all the rules have been evaluated so it can’t be used to prevent null pointer exceptions in condtions.

 

Another approach which may (or may not) work is to get your condition to actually throw an exception if the condition doesn’t match this will normally stop the execution as well.

Eg

function isNull(Object o)

                if(o == null) throw new ValidationException(“Object is null  :(“);

return false;

end

 

rule “blagh”

when

          eval(isNull(someObject))

then

          //this will never be reached as an exception will be thrown

End

 

(you may need to fiddle with syntax and use a java method or something.

The other key thing to remember though is if you have structured your rules correctly (null check as the very first condition) then all 100 rules will share the same null check node and you will only be doing it once not 100 times anyway and so it will make little difference on performance. (And a null check is very fast anyway). Don’t optimize until you know you actually have to – there are likely to be other far more important performance issues in your application anyway

 

Thomas