Re: [rules-users] RuntimeDroolsException as Solver concludes execution
Looks like an NPE in your rule.
Maybe maintenanceSlot or something is null.
You should raise an issue with drools-core (drools expert) that it
should give a better runtime error to show on which line it NPE'ed.
With kind regards,
Geoffrey De Smet
dweppenaar schreef:
Hi.
I am experiencing the following exception:
org.drools.RuntimeDroolsException: Exception executing ReturnValue
constraint org.drools.rule.ReturnValueRestriction@a5f6c234 :
java.lang.NullPointerException.
The rule that is causing the exception to occur is the following:
rule "spreadOvertime"
when
$violatingTask :
MaintenanceTask(eval(maintenanceSlot.getAvailability() == 1), motor != null,
maintenanceTechnician != null, $overtimeTaskID : id);
ArrayList( $numberOfViolations : size ) from collect(
MaintenanceTask(
id == ($overtimeTaskID + 1) ||
id == ($overtimeTaskID + 2) ||
id == ($overtimeTaskID - 1) ||
id == ($overtimeTaskID - 2),
eval(maintenanceSlot.getAvailability() >= 1) ) );
then
insertLogical(new IntConstraintOccurrence("spreadOvertime",
ConstraintType.NEGATIVE_SOFT,
$numberOfViolations, $violatingTask, $numberOfViolations));
//System.out.println("Rule Fired: spreadOvertime ( number of
violations:" + $numberOfViolations + " for task " + $violatingTask +
")");
end
The purpose of the rule is to spread the closer to normal maintenance
shifts.
Just to clarrify what the objects are:
MaintenanceTask: Consists of a MaintenanceSlot, MaintenanceTechnician and
Motor
MaintenanceSlot: Day, Timeslot, Availability and Index
The 'availability' of a MaintenanceSlot specifies whether it is considered
Overtime, ProductionTime or Normal Maintenance
This exception is thrown at the end of solving as the solver (I presume) is
supposed to return the best solution. The score is calculating and updating
but at the end of the specified step count, this exception occurs.
If I comment this rule out, no exception.
Any help would be appreciated!
Regards,
De Ville