Cron timer testing with psuedo clock in Drools Fusion? - drools

Question

I am trying to test the firing of a rule based on a cron timer using the pseudo clock in Drools Fusion 5.5. I want the rule to fire everyday at 1am:
rule "CALCULATING DATE FOR NEXT DAY"
timer (cron:00 00 01 * * ?)
no-loop
when
$summary: FxSummary(sameDayCcyFlag == false)
then
BusinessDayUtil b = new BusinessDayUtil();
modify($summary) {
setSettlementDate(b);
}
end
I then do the following in my test case:
PseudoClockScheduler timeService = ( PseudoClockScheduler ) ksession.getSessionClock();
DateFormat df = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ss.SSSZ" );
Date date = df.parse( "2014-01-16T01:00:00.000-0000" );
Summary sum = new Summary("YEN").setSameDayCcyFlag(false);
ksession.fireAllRules();
timeService.advanceTime( date.getTime(), TimeUnit.MILLISECONDS );
ksession.fireAllRules();
It doesn't seem to do anything...no indication that the timer fired or anything. I've also tried to insert a date at say 12:59:50 and advanced the clock 10sec. Also, fireUntilHalt to have the engine running, etc. Nothing seems to work. Am I using this correctly? Does the pseudo clock work with timers? Also, does it fire "missed" timers if I advance the clock past a timer that was supposed to fire?

Answer 1

Think about how cron can be implemented. The basic function is timer, and this works like ye olde kitchen's egg-timer: at one point in time you wind it up, and then it'll ring 4 or 5 minutes later. Thus, for the next cron ring of the bell, the Cook will have to look at the clock and calculate the interval to the indicated point in time.
You'll have to let the Cook look at the clock some time before the next 1:00am, say, around midnight. The code goes something like this, with advance() overloaded with Date and long to advance the pseudo-clock:
date = df.parse( "2014-01-15T00:00:00.000-0000" ); // Note: midnight
advance( date );
kSession.fireAllRules(); // (Ah, ring in one hour!)
advance( 1000*60*60 );
kSession.fireAllRules(); // Ring!
advance( 24*1000*60*60 );
kSession.fireAllRules(); // Ring!
The postman only rings twice ;-)