Table of Contents

Class CronTriggerImpl

Namespace
Quartz.Impl.Triggers
Assembly
Quartz.dll

A concrete ITrigger that is used to fire a IJobDetail at given moments in time, defined with Unix 'cron-like' definitions.

[Serializable]
public class CronTriggerImpl : TriggerBase, IOperableTrigger, IMutableTrigger, IEquatable<TriggerBase>, ICronTrigger, ITrigger
Inheritance
CronTriggerImpl
Implements
Inherited Members

Remarks

For those unfamiliar with "cron", this means being able to create a firing schedule such as: "At 8:00am every Monday through Friday" or "At 1:30am every last Friday of the month".

The format of a "Cron-Expression" string is documented on the CronExpression class.

Here are some full examples:

Expression Meaning
"0 0 12 * * ?"" /> Fire at 12pm (noon) every day" />
"0 15 10 ? * *"" /> Fire at 10:15am every day" />
"0 15 10 * * ?"" /> Fire at 10:15am every day" />
"0 15 10 * * ? *"" /> Fire at 10:15am every day" />
"0 15 10 * * ? 2005"" /> Fire at 10:15am every day during the year 2005" />
"0 * 14 * * ?"" /> Fire every minute starting at 2pm and ending at 2:59pm, every day" />
"0 0/5 14 * * ?"" /> Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day" />
"0 0/5 14,18 * * ?"" /> Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day" />
"0 0-5 14 * * ?"" /> Fire every minute starting at 2pm and ending at 2:05pm, every day" />
"0 10,44 14 ? 3 WED"" /> Fire at 2:10pm and at 2:44pm every Wednesday in the month of March." />
"0 15 10 ? * MON-FRI"" /> Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday" />
"0 15 10 15 * ?"" /> Fire at 10:15am on the 15th day of every month" />
"0 15 10 L * ?"" /> Fire at 10:15am on the last day of every month" />
"0 15 10 ? * 6L"" /> Fire at 10:15am on the last Friday of every month" />
"0 15 10 ? * 6L"" /> Fire at 10:15am on the last Friday of every month" />
"0 15 10 ? * 6L 2002-2005"" /> Fire at 10:15am on every last Friday of every month during the years 2002, 2003, 2004 and 2005" />
"0 15 10 ? * 6#3"" /> Fire at 10:15am on the third Friday of every month" />

Pay attention to the effects of '?' and '*' in the day-of-week and day-of-month fields!

NOTES:

  • Support for specifying both a day-of-week and a day-of-month value is not complete (you'll need to use the '?' character in on of these fields).
  • Be careful when setting fire times between mid-night and 1:00 AM - "daylight savings" can cause a skip or a repeat depending on whether the time moves back or jumps forward.

Constructors

CronTriggerImpl(string, string, string, TimeProvider?)

Create a CronTriggerImpl with the given name, group and expression.

public CronTriggerImpl(string name, string group, string cronExpression, TimeProvider? timeProvider = null)

Parameters

name string

The name of the ITrigger

group string

The group of the ITrigger

cronExpression string

A cron expression dictating the firing sequence of the ITrigger

timeProvider TimeProvider

A TimeProvider to use, if not specified defaults to TimeProvider.System

Remarks

The start-time will also be set to the current time, and the time zone will be set to the system's default time zone. Everything else this trigger needs is a settable property, so the object-initializer form new CronTriggerImpl { Key = ..., JobKey = ..., EndTimeUtc = ... } replaces the constructor overloads that used to spell out each combination.

Exceptions

ArgumentNullException

name or group are null.

CronTriggerImpl(TimeProvider?)

Create a CronTriggerImpl with no settings.

public CronTriggerImpl(TimeProvider? timeProvider = null)

Parameters

timeProvider TimeProvider

Time provider instance to use, defaults to System

Remarks

The start-time will also be set to the current time, and the time zone will be set to the system's default time zone.

Properties

CronExpression

Set the CronExpression to the given one. The TimeZone on the passed-in CronExpression over-rides any that was already set on the Trigger.

public CronExpression? CronExpression { get; set; }

Property Value

CronExpression

The cron expression.

CronExpressionString

Gets or sets the cron expression string.

public string? CronExpressionString { get; set; }

Property Value

string

The cron expression string.

EndTimeUtc

Get or sets the time at which the CronTrigger should quit repeating - even if repeatCount isn't yet satisfied.

public override DateTimeOffset? EndTimeUtc { get; set; }

Property Value

DateTimeOffset?

FinalFireTimeUtc

Returns the last UTC time at which the ITrigger will fire, if the Trigger will repeat indefinitely, null will be returned.

Note that the return time *may* be in the past. 

public override DateTimeOffset? FinalFireTimeUtc { get; }

Property Value

DateTimeOffset?

HasMillisecondPrecision

Tells whether this Trigger instance can handle events in millisecond precision.

protected override bool HasMillisecondPrecision { get; }

Property Value

bool

MayFireAgain

Used by the IScheduler to determine whether or not it is possible for this ITrigger to fire again.

If the returned value is false then the IScheduler may remove the ITrigger from the IJobStore. 

public override bool MayFireAgain { get; }

Property Value

bool

MisfireInstruction

What the scheduler does when this trigger misses a firing.

public CronTriggerMisfireInstruction MisfireInstruction { get; }

Property Value

CronTriggerMisfireInstruction
See Also

NextFireTimeUtc

Returns the next time at which the ITrigger is scheduled to fire. If the trigger will not fire again, null will be returned. Note that the time returned can possibly be in the past, if the time that was computed for the trigger to next fire has already arrived, but the scheduler has not yet been able to fire the trigger (which would likely be due to lack of resources e.g. threads).

public override DateTimeOffset? NextFireTimeUtc { get; set; }

Property Value

DateTimeOffset?

Remarks

The value returned is not guaranteed to be valid until after the ITrigger has been added to the scheduler.

PreviousFireTimeUtc

Returns the previous time at which the ITrigger fired. If the trigger has not yet fired, null will be returned.

public override DateTimeOffset? PreviousFireTimeUtc { get; set; }

Property Value

DateTimeOffset?

StartTimeUtc

Returns the date/time on which the trigger may begin firing. This defines the initial boundary for trigger firings the trigger will not fire prior to this date and time.

public override DateTimeOffset StartTimeUtc { get; set; }

Property Value

DateTimeOffset

TimeZone

Sets the time zone for which the CronExpressionString of this ICronTrigger will be resolved.

public TimeZoneInfo TimeZone { get; set; }

Property Value

TimeZoneInfo

The time zone.

Remarks

If CronExpressionString is set after this property, the TimeZone setting on the CronExpression will "win". However if CronExpressionString is set after this property, the time zone applied by this method will remain in effect, since the string cron expression does not carry a time zone!

Methods

Clone()

Clones this instance.

public override ITrigger Clone()

Returns

ITrigger

ComputeFirstFireTimeUtc(ICalendar?)

Called by the scheduler at the time a ITrigger is first added to the scheduler, in order to have the ITrigger compute its first fire time, based on any associated calendar.

After this method has been called, NextFireTimeUtc should return a valid answer. 

public override DateTimeOffset? ComputeFirstFireTimeUtc(ICalendar? calendar)

Parameters

calendar ICalendar

Returns

DateTimeOffset?

the first time at which the ITrigger will be fired by the scheduler, which is also the same value NextFireTimeUtc will return (until after the first firing of the ITrigger).

GetFireTimeAfter(DateTimeOffset?)

Returns the next time at which the ITrigger will fire, after the given time. If the trigger will not fire after the given time, null will be returned.

public override DateTimeOffset? GetFireTimeAfter(DateTimeOffset? afterTimeUtc)

Parameters

afterTimeUtc DateTimeOffset?

Returns

DateTimeOffset?

GetPreviousValidTimeBefore(DateTimeOffset)

Returns the time before the given time that this ICronTrigger will fire.

protected DateTimeOffset? GetPreviousValidTimeBefore(DateTimeOffset date)

Parameters

date DateTimeOffset

The date.

Returns

DateTimeOffset?

GetScheduleBuilder()

Get a IScheduleBuilder that is configured to produce a schedule identical to this trigger's schedule.

public override IScheduleBuilder GetScheduleBuilder()

Returns

IScheduleBuilder

Triggered(ICalendar?)

Called when the IScheduler has decided to 'fire' the trigger (Execute the associated IJob), in order to give the ITrigger a chance to update itself for its next triggering (if any).

public override void Triggered(ICalendar? calendar)

Parameters

calendar ICalendar
See Also

UpdateAfterMisfire(ICalendar?)

This method should not be used by the Quartz client.

To be implemented by the concrete classes that extend this class.

The implementation should update the ITrigger's state according to the misfire instruction the ITrigger was built with, read as MisfireInstructionCode. 

public override void UpdateAfterMisfire(ICalendar? calendar)

Parameters

calendar ICalendar

UpdateWithNewCalendar(ICalendar, TimeSpan)

Updates the trigger with new calendar.

public override void UpdateWithNewCalendar(ICalendar calendar, TimeSpan misfireThreshold)

Parameters

calendar ICalendar

The calendar to update with.

misfireThreshold TimeSpan

The misfire threshold.

ValidateMisfireInstruction(int)

Validates the misfire instruction.

protected override bool ValidateMisfireInstruction(int misfireInstruction)

Parameters

misfireInstruction int

The misfire instruction.

Returns

bool

WillFireOn(DateTimeOffset, bool)

Determines whether the date and (optionally) time of the given Calendar instance falls on a scheduled fire-time of this trigger.

Note that the value returned is NOT validated against the related ICalendar (if any). 

public bool WillFireOn(DateTimeOffset timeUtc, bool dayOnly = false)

Parameters

timeUtc DateTimeOffset

The time to compare.

dayOnly bool

If set to true, the method will only determine if the trigger will fire during the day represented by the given Calendar (hours, minutes and seconds will be ignored).

Returns

bool

See Also

ITrigger
ISimpleTrigger
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