global variable in optaplanner

Question

In drools rule file how do I set the value of (or initialize) a global variable for optaplanner. My use case is following:

I want to declare a global java map that is constant and will not change during the execution. Every rule will access the map to check for a value, if value is in the map then rule will evaluate to false. The map is being generated before execution starts by accessing data in files/database.

This link https://issues.jboss.org/browse/PLANNER-94 is also requesting the access to global variable but this feature is rejected now.

How do i use the hack defined in this link: Setting global variables in working memory in Drools planner, from which object i should get CustomSolverPhaseCommand? [I am not able to comment on this post yet because i don't have enough reputation, sorry if it seems duplicate question].

I am creating SolverFactory from xml Resource and xml file contains the path to .drl file. Just like in .drl we can access object HardSoftScoreHolder scoreHolder, I want to access the map in the same way in 'then' part of rule.

can anyone please help?

Answer 1

Look at the examples that have a class that ends with Parameterization instead, such as ConferenceParametrization, this is probably a better alternative than globals.