[rules-users] How to pass a "global" reference date to rules
Wolfgang Laun
wolfgang.laun at gmail.com
Tue Feb 5 09:38:30 EST 2013
On 05/02/2013, pdario <dario.piantanida at gmail.com> wrote:
> I see, I'll have a look at the classes you mention.
>
> But what if I need to calculate a time difference from today to another
> date
> (say "order expire date")?
> Would a "new Date()" in the rules give me the "pseudo" time?
java.util.Date is not the session clock. The default clock's
getCurrentTime returns System.currentTimeMillis() and the pseudo-clock
returns whatever you set it to.
You'll have to base all your calculations with dates in fact data on the
value returned by the session clock. I suppose you'll want to do this
in RHS code, so this is one approach:
global MyClock myClock;
rule "x"
when
$d : Date() // or (... $d: orderExpireDate,... )
then
System.out.println( $d + " diff in days: " + myClock.daysTo( $d ) );
end
This is a primitive implementation of MyClock:
public class MyClock {
private static final long MS_PER_DAY = 24*60*60*1000;
public static SessionClock sessionClock;
public MyClock( SessionClock sessionClock ){
this.sessionClock = sessionClock;
}
public int daysTo( Date d ){
long dTime = d.getTime();
int dDays = (int)((dTime - dTime % MS_PER_DAY)/MS_PER_DAY);
long sTime = sessionClock.getCurrentTime();
int sDays = (int)((sTime - sTime % MS_PER_DAY)/MS_PER_DAY);
return dDays - sDays;
}
}
>
> Thank you!
>
>
>
> --
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