Re: [rules-users] How to check if a property IS null ?

Thank you. "this == null" is weird indeed in Java, but I honestly don't know how to express this expression in Drools DSL. A more realistic rule would be: when $product : Product( ) Double( this == null ) from bookingService.getQty( $product ) So what I want to do is detect when a method call returns null. The method call can contain parameters but it can be a simple method like before. How to do this? Thank you. Hendy -- View this message in context: http://drools.46999.n3.nabble.com/How-to-check-if-a-property-IS-null-tp40... Sent from the Drools: User forum mailing list archive at Nabble.com.