Schedule Task at Interval based on Start time in Quartz

Question

I am new to Quartz and want to use it to schedule scripts in SQLServer using a service for clients using SQL Server Express.

I need a user to be able to schedule a task to run, say every second week starting from a particular date. eg: StartDate = 1/Jan/2013 12:00PM (Tuesday) and repeat every 14 days.

In the setup for the job, there is a StartTime (datetime), IntervalUnit (second, minute, hour, day, week, year) and RepeatsEvery (the number of intervals to fire after the start date).

eg: a setup of StartDate = "1/JAN/2013 12:00PM" and IntervalUnit = "DAY" and RepeatsEvery= 14, would fire the job every 2nd Tuesday at 12:00PM. If the StartDate is already passed, I need the job to fire on the next start date, eg: If I started the service today (18/JAN/2013), the next startdate would be 29/JAN/2013 12:00PM

I can't figure out how to make this work in Quartz, using the Calendar Trigger. Is this something that is built in to Quartz or do I need to calculate a new StartTime on startup?

Assuming I have to calculate a new StartTime, is there any built in function or neat shortcut for this, or do I need a function similar to this for each IntervalUnit:

'Days
Dim diff As Integer
diff = Now.Subtract(.StartTime).TotalDays
Dim offset As Integer
offset = .RepeatsEvery - (diff Mod .RepeatsEvery)
offset = Now.AddDays(offset).Subtract(.StartTime).TotalDays 'Get the days from Start t preserve time of day
Start = .StartTime.AddDays(offset)

score 1 · Accepted Answer · answered Jan 18 '13 at 10:41

You can create a trigger and then call trigger.GetFireTimeAfter(DateTime.Now) to calculate the new start date and then build and new trigger with the new StartDate.

The following is C#, but hopefully gives you the idea

var trigger = TriggerBuilder.Create()
                   .StartAt( new DateTimeOffset(new DateTime(2013,1,1)))
                   .WithSimpleSchedule(x=>x.RepeatForever()
                                          .WithInterval(new TimeSpan(14,0,0,0)))
                    .Build();                


var newStartingPoint = trigger.GetFireTimeAfter(DateTime.Now);

if (newStartingPoint.HasValue)  
{ 
     trigger = ((ISimpleTrigger) trigger).GetTriggerBuilder()
                                        .StartAt(newStartingPoint.Value)
                                        .Build();    
}

.GetTriggerBuilder() isn't available on ITrigger, which is why you have to cast the trigger to ISimpleTrigger, but the same principle works with other triggers.

Schedule Task at Interval based on Start time in Quartz

1 Answers1