[rules-users] not able to use map as global variable to get the object

Hi, I know some questions are raised regarding using map in drools. But most of them have answered that Map to be added as part of working memory and not global. My question is based on same lines. I have global variable of the the type map. I insert my facts in working memory. This facts are basically keys for the entities in map. Map will contain elements whose keys will be met or not. If element in map is found then i have to assign it to the variable so that i can use it ahead. I have tried may ways but i didnt get how to work with it. Similiarly i have multiple maps of different elements and i have to be sure which map to be used to retrieve element hence i dont want to set map in working memory. Below is the *trace of code* that fires Null pointer exception import java.util.List; import java.util.ArrayList; import java.util.Map; import java.util.HashMap; import domainObjects.ConcPercentRef; import domainObjects.EncapsulatingObject; global java.util.Map encapsulationMap; rule "test rule" no-loop when $key : EncapsulatingObject(id != 0 ) $object : *EncapsulatingObject(encapsulationMap[$key]* != null) then System.out.println("value is ::: "+encapsulationMap.get($key)); end *Exception trace * Exception in thread "main" [Error: null pointer: encapsulationMap[$key]] [Near : {... encapsulationMap[$key] != null ....}] ^ [Line: 1, Column: 1] at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain i have also tried using Map(encapsulationMap[$key] !=null but it fails. It does not throws exception but it dosent enters in then clause because some of the keys are present. Be sure of that. Any help will be highly appreciated Thanks Avin -- View this message in context: http://drools.46999.n3.nabble.com/not-able-to-use-map-as-global-variable-... Sent from the Drools: User forum mailing list archive at Nabble.com.