We are using Maps (HashMaps) in our rules and the only way we have found to access keys and values in the Map in the "when" clauses is thru use on eval() which I know is a big no-no by rules purists. Is there a better way, maybe some shorthand I'm not familiar with to deal with Maps in the when clause? Thanks, Dennis _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

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: > > Denis, > > If you are using latest build from trunk (I'm not sure it already works > in MR3), you can use a simplified MVEL syntax: > > when > Person( address["business"].phone == "99999999" ) > then > ... > end > > Although, the above will be converted into an inline-eval. Not as bad > as > a top level eval, but still more costly then using regular fields. > > []s > Edson > > 2007/7/19, Ryan, Dennis (Dennis) <dennisryan(a)avaya.com&gt;: >> >> We are using Maps (HashMaps) in our rules and the only way we have found >> to access keys and values in the Map in the "when" clauses is thru use on >> eval() which I know is a big no-no by rules purists. Is there a better >> way, >> maybe some shorthand I'm not familiar with to deal with Maps in the when >> clause? >> >> >> >> Thanks, >> >> Dennis >> >> _______________________________________________ >> 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 > > _______________________________________________ > rules-users mailing 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