From: mviens <mike(a)viens.com&gt; Subject: [rules-users] Question about Drools accessing a global HashMap and comparing it to an object value To: rules-users(a)lists.jboss.org Date: Tuesday, January 25, 2011, 3:37 PM MyObj is a Java object that contains:     String state;     String code;     public void addError(String message); myObjList is an ArrayList<MyObj> containing from 2 to 20,000 objects state2CodeMap is a HashMap<String, ArrayList<String>> containing an entry for each US state. The associated ArrayList contains a minimum of 1 entry, up to 200 entries. I need to create a rule that checks all of the MyObj objects in myObjList, gets the appropriate ArrayList from state2CodeMap based on myObj.state and then if myObj.code not memberOf $codeList, run the "then" portion of the rule. I have created about 60 fairly simple rules, that are working just fine, but this one is a little too complex for me to userstand how to write it in Drools. Looking at this page ( http://blog.athico.com/2007/06/chained-from-accumulate-collect.html http://blog.athico.com/2007/06/chained-from-accumulate-collect.html ), I can see that nested "from" seems to be supported, but the page seems to be for Drools 4. Plus, I have had to teach myself Drools in the past week. I could really use some help with this. Any assistance is greatly appreciated! Mike V.     global List myObjList;     global HashMap state2CodeMap;     # this rule is working just fine!     rule "Check for null State"         when             $objs : ArrayList() from collect(MyObj(state == null || state == "") from myObjList)         then             for (MyObj myObj : (ArrayList<MyObj>)$objs)             {                 myObj.addError("State must have a value");             }     end     # I really have no idea how to write this rule     rule "Check for valid code"         when             $objs : ArrayList() from collect(MyObj())         then             for (MyObj myObj : (ArrayList<MyObj>)$objs)             {                 myObj.addError("Code is not valid for the State");             }     end -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Question-about-Drools... 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

Hi Greg, Thank you for the reply. I converted the rules back to being processed in singular mode versus through an ArrayList as you recommended. I am curious about the reason though -- is it a performance issue or does it just make it more difficult to work with within the rule? I tried your recommendation of the rule, but it caused an error: rule "Check for valid code" when obj : MyObj(objState : state, objCode : code) codes : State2Code(state == objState && objCode not memberOf codes) then obj.addError("Code is not valid for the State"); end BuildError: Unable to create Field Extractor for 'objCode' of '[ClassObjectType class=com.abc.xyz.StateFips]' in rule 'Check for valid Code' When I changed the rule to this, the error is gone and it worked just fine. rule "Check for valid code" when obj : MyObj(objState : state, objCode : code) codes : State2Code(state == objState && codes not contains objCode) then obj.addError("Code is not valid for the State"); end Do you have any thoughts on why the first rule does not work but the second one does? Is it a bug? The only difference between the rule I have and the one you suggested was using a comma versus ==. I tried with the comma, but the error remained. I am using Drools 5.1.1. Mike V. -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Question-about-Drools... 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