[rules-users] variable instance check?
In java, I can check to see if a 2 variables references the same
instance as such:
Object a = new Object();
Object b = a;
a == b
Is there a way to do this in Drools? For instance, if there is an
object in working memory and it is a specific instance, I do not want to
fire the rule again. ie:
rule "User Lookup UserKey"
salience 10000
when
com.kronos.taws.model.User(empId == null, $key:empIdKey)
then
System.out.println("Firing 2!");
insert($key);
end
I want to ensure that $key is not already in working memory. But mind
you, there might be other $keys that are in working memory that do not
belong to this particular com.kronos.taws.model.User instance. I do not
want this rule to fire because I have subsequent rules that will make
empId a value other than null.
I attempted to do this:
rule "User Lookup UserKey"
when
com.kronos.taws.model.User(empId == null, $key:empIdKey)
not UserKey(this == $key)
then
System.out.println("Firing 2!");
insert($key);
end
However, I still think this is doing an equality check because once the
$key object is updated in another rule, this rule is fired again!
Thanks in advance!
Eric