Quartz. Net c tutorial - course 4: triggers

and jobs equally , triggers It's easy to use , But there are also some customized options to understand , Otherwise, it is difficult to give full play Quartz.NET The function of . in addition , There are also many different types trigger, It can meet all kinds of scheduling demand .

Common Trigger Attributes

be-all trigger class , Except for one TriggerKey properties , There are other common attributes . These attribute values are constructed trigger definition It's time for TriggerBuilder To assign a value ( The following example will introduce ).

Common property :

• JobKey:  stay trigger When triggered , For unique indication trigger object .
• StartTimeUtc:  Indicates when to trigger First scheduling . Its value is a DateTimeOffset object , Defines a time on the calendar . There are some trigger type , trigger Will trigger at the beginning , other trigger A scheduler start time will be marked . That means you can give trigger A scheduling time , similar : " The fifth day of January " , If StartTimeUtc The value of is 4 month 1 Number , Then we have to wait for months trigger Will trigger .
• EndTimeUtc:  Indicate when to start trigger Don't be dispatched again . in other words If trigger The scheduling time is Every month on the fifth , And EndTimeUtc The value is 7 month 1 Number , So this trigger The last execution time of is 6 month 5 Number .

Other properties are discussed in detail below .

Priority

If it's in your Quartz.NET There are several working threads in the thread pool , Quartz.NET There may not be enough resources to immediately execute trigger. At this time, you need to control Quartz.NET When there are idle worker threads , Which one? trigger Will get execution time . This needs to be given trigger set priority . If you don't set priorities , So the default value is 5, Any integer value can be set on the priority , Integer or negative number is ok .

Be careful :  The value of priority is only executed at the same time trigger It works . The scheduling time is early trigger Regardless of the priority, it will be later than the scheduling time trigger Execute first .

Be careful :  When one trigger It is detected that it needs to be restored , Then its priority will be restored to the same as the previous priority .

Misfire Instructions

misfire It means a trigger Because his scheduler was turned off, he missed its trigger time , Or because of Quartz.NET There are no available threads in the thread pool to execute trigger Of job. Different trigger Types have their own misfire Indicator . The default with 'smart policy' Indicator - It will be based on trigger Type and configuration to dynamically determine its own behavior . When the scheduler starts
, It looks for all missed triggers triggers, Then update according to their respective configured indicators triggers.

Calendars

Quartz.NET Calendar Object implementation ICalendar Interface , stay trigger When stored in the scheduler, it will interact with trigger Connect . Calendars Can be used from trigger Move a specific time block out of the trigger period of . for example , You have one. trigger In the morning of every working day 9:30, And then I added a Calendar To remove all holidays .

Calendar It can be any implementation ICalendar Serializable object of interface , The interface is as follows :

namespace Quartz
{
      
    public interface ICalendar
    {
      
        string Description {
       get; set; }

        ICalendar CalendarBase {
       set; get; }

        bool IsTimeIncluded(DateTimeOffset timeUtc);

        DateTime GetNextIncludedTimeUtc(DateTimeOffset timeUtc);
    }
} 

although calendarEven You can move out of periods as small as milliseconds , At that time, you may want to move out of the whole day , For convenience , Quartz.NET Defined a HolidayCalendar class .

Calendars Must be initialized and used AddCalendar() Sign up to scheduler. about HolidayCalendar, After initialization , You need to use it AddExcludedDate(DateTime date) Method to fill in the date you want to move out . The same calendar Objects can be given to multiple triggers Use :

Calendar Example

    HolidayCalendar cal = new HolidayCalendar();
    cal.AddExcludedDate(someDate);

    sched.AddCalendar("myHolidays", cal, false);

    ITrigger t = TriggerBuilder.Create()
        .WithIdentity("myTrigger")
        .ForJob("myJob")
        .WithSchedule(CronScheduleBuilder.DailyAtHourAndMinute(9, 30)) // execute job daily at 9:30
        .ModifiedByCalendar("myHolidays") // but not on holidays
        .Build();

    // .. schedule job with trigger

    ITrigger t2 = TriggerBuilder.Create()
        .WithIdentity("myTrigger2")
        .ForJob("myJob2")
        .WithSchedule(CronScheduleBuilder.DailyAtHourAndMinute(11, 30)) // execute job daily at 11:30
        .ModifiedByCalendar("myHolidays") // but not on holidays
        .Build();

    // .. schedule job with trigger2 

The next lesson introduces triggers Structural details of . Now? , Just know that the above code constructs two trigger, Each is scheduled to execute every day . however calendar It will make them skip the scheduling time .

You can see Quartz.Impl.Calendar Is there anything in the namespace that meets your needs ICalendar Realization .

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