I'm using drools-5.3.0.Beta1. I've following rule file:

import java.util.*;

declare Student

   name : String @key

   subjectGradeMap : HashMap   

end

 

rule "Subject grade points"

dialect "mvel"

when

   $u : Student()

then

   if($u.subjectGradeMap == null)

   {

      $u.subjectGradeMap = new HashMap<String,Integer>();

   }

   $u.subjectGradeMap["CompSc"] += 100;

   System.out.println("Marks added");

end

I get following error while rule compilation:

Unable to Analyse Expression if($u.subjectGradeMap == null);

   {

      $u.subjectGradeMap = new HashMap<String,Integer>();

   };

   $u.subjectGradeMap["CompSc"] += 100;

   System.out.println("Marks added");:

[Error: was expecting type: java.lang.Object; but found type: <Unknown>]

[Near : {... if($u.subjectGradeMap == null) ....}]

             ^

[Line: 1, Column: 1] : [Rule name='Subject grade points']

Please let me know if this is correct usage in the above scenario.

Thanks,

Neel