Are these dynamic facts you're working with? If they aren't (and at least your new Invoke object is not), then try: then Invoke inv = new invoke(); $web.setInvoke(inv); insert(inv); update($web); end -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of psyduck Sent: Friday, May 09, 2008 2:20 PM To: rules-users(a)lists.jboss.org Subject: [rules-users] Nullpointer inserting fact. Hey, I ve got a class WebService{ getter/setter for invoke property } then i got the following rules rule "..." salience 10 when $web : WebService ( ) then Invoke inv = new invoke(); $web.setInvoke(inv); insert(inv); end this succeeds,but then the following rule : rule "..." salience 9 when $inv : Invoke( ) $web : WebService ( invoke == $inv); then ... end never gets executed,because he doesnt find a webservice with same invoke, (according to debug information,they are the same invoke object) Is it possible that this happens because when i inserted the webservice in the workingmemory, the invoke property was not yet defined(=null)? Does anyone know a solution for this? Thx in advance -- View this message in context: http://www.nabble.com/Nullpointer-inserting-fact.-tp17100525p17100525.html Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Improve your rule constraints: rule "..." ruleflow-group "invoke" salience 10 when $web : WebService ( invoke == null ) then Invoke inv = new invoke(); $web.setInvoke(inv); update( $web ); insert(inv); end []s Edson 2008/5/12 psyduck <psyduck101(a)gmail.com&gt;: -- Edson Tirelli JBoss Drools Core Development Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com