Hi, I am placing objects in the Hashmap that were retrieved from the database. There are currently a hundred objects that I'm storing in the HashMap. I just made a simple example earlier :) . What works for me now is putting the getting of the values in the eval(). However, I don't know how to assign the values that I've taken from the Map. eval( ( (MyClass)mapOfObj.get("keyOfObj")).getId() > 30); How do I assign (MyClass)mapOfObj.get("keyOfObj") to a variable? tnx, shaz ----- Original Message ---- From: "Anstis, Michael (M.)" <manstis1(a)ford.comTo: Rules Users List <rules-users(a)lists.jboss.orgSent: Friday, November 2, 2007 12:17:51 AM Subject: RE: [rules-users] Accessing maps (hashmaps) keys and values in rules By way of example (if you misunderstand how the rule engine should be used):- rule chkobj when $o : MyClass( id == "1", name == "name" ) then //Do something else $o.doSomething(); end From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Edson Tirelli Sent: 01 November 2007 15:48 To: Rules Users List Subject: Re: [rules-users] Accessing maps (hashmaps) keys and values in rules Shaz, We strongly advise you to move to 4.0.3, but this is not related to your problem. I think you are misunderstanding something. Why are you using the global map to store your fact? Simply insert it into the working memory and it will work fine. []s Edson 2007/11/1, Shaz Tumulak <shauii(a)yahoo.com&gt;: Hi, I can't seem to make this syntax work in Drools 4.0.2. Pls. see my sample code below. ________________________________________ class MyClass { String id; String name; MyClass(String id, String name){ this.id = id; this.name = name; } : getter, setter methods : } MyClass obj = new MyClass("1"", "name"); TreeMap<String, MyClass mapOfObj = new TreeMap<String, MyClass>(); mapOfObj.put("keyOfObj", obj); ________________________________________ DRL file ------- global java.util.TreeMap mapOfObj; rule chkobj when obj : MyClass(mapOfObj["keyOfObj"].id == "1"); eval(obj.getName() == "name"); ________________________________________ I'm getting this error: org.drools.RuntimeDroolsException: java.lang.NullPointerException at org.drools.rule.EvalCondition.isAllowed(EvalCondition.java:76) Is my syntax correct and has someone used this in 4.0.2 or should I move on to Drools 4.0.3? Thanks in advance. Regards, shaz Edson Tirelli-3 wrote: you are using latest build from trunk (I'm not sure it already works in MR3), you can use a simplified MVEL syntax: "99999999" ) > then > ... end converted into an inline-eval. Not as bad eval, but still more costly then using regular fields. > []s > Edson 2007/7/19, Ryan, Dennis (Dennis) <dennisryan(a)avaya.com our rules and the only way we have found values in the Map in the "when" clauses is thru use on which I know is a big no-no by rules purists. Is there a better > way, Maps in the when > clause? >>>> Thanks, >>> Dennis >> _______________________________________________ mailing list >> rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users >> -- JBoss Rules Core Developer division of Red Hat @ www.jboss.com _______________________________________________ list > rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users shauii(a)yahoo.com -- View this message in context: http://www.nabble.com/Accessing-maps-%28hashmaps%29-keys-and-values-in-ru... 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 -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com ____________________________________________________ Organic foods - just how healthy is health food? Be a better foodie Find out at Yahoo! Answers - http://ph.answers.yahoo.com/