RE: [rules-users] Accessing maps (hashmaps) keys and values in rules

IMHO you should still think about putting the Map values into working memory. This would both simplify your rules and make their execution faster (eval cannot be indexed, if I remember correctly). You might need to adapt your data model representation into one that is more efficient for use in a RETE network. Can you explain your use case to help understand? Unless you have very good reason to keep the facts in the Map your life will be more difficult than it need be. An "eval" returns a boolean indiciating whether the "pattern" matched and therefore, whilst you can reference other bound LHS facts, you cannot bind other objects to variables. Thanks, Mike _____ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of shaz Sent: 02 November 2007 02:32 To: Rules Users List Subject: Re: [rules-users] Accessing maps (hashmaps) keys and values in rules 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.com&gt; To: Rules Users List <rules-users(a)lists.jboss.org&gt; Sent: 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: <mailto:dennisryan@avaya.com> >: shauii(a)yahoo.com -- View this message in context: http://www.nabble.com/Accessing-maps-%28hashmaps%29-keys-and-values-in-rules -tf4112197.html#a13524477 <http://www.nabble.com/Accessing-maps-%28hashmaps%29-keys-and-values-in-rule s-tf4112197.html#a13524477> 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 _____ Platonic friends of the opposite sex - the real deal? Be a better buddy Find <http://ph.answers.yahoo.com/dir/index;_ylt=AsCq4OcgSoQ9qZZdke2cnGhL5Qt.;_yl v=3?link=over&sid=396545433> out at Yahoo! Answers