com.silverpeas.scheduler.trigger
Class JobTrigger

java.lang.Object
  com.silverpeas.scheduler.trigger.JobTrigger

Direct Known Subclasses:

CronJobTrigger, FixedPeriodJobTrigger

public abstract class JobTrigger
extends Object

A trigger of a job execution. A job trigger specifies the time, regular or not, at which a job must be executed. A job trigger is a schema about the triggering of job executions. It is is used for actually scheduling a job in the scheduling backend. This class is an abstract one from which new job trigger can be defined. Currently two types of trigger is supported: a trigger with an Unix-like cron expression and another one with a simple periodicity.

Constructor Summary

JobTrigger()

Method Summary

abstract void	accept(JobTriggerVisitor visitor) Accepts the specified visitor to visit it.
Date	getStartDate() Gets the date at which the trigger's scheduling should start.
JobTrigger	startAt(Date startDate) Sets the date at which the trigger's scheduling should start.
static JobTrigger	triggerAt(String cron) Creates a job trigger that will fire a job execution at given moments in time, defined by the specified cron expression.
static JobTrigger	triggerEvery(int time, TimeUnit unit) Creates a job trigger that will fire a job execution every the specified time.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JobTrigger

public JobTrigger()

Method Detail

accept

public abstract void accept(JobTriggerVisitor visitor)

Accepts the specified visitor to visit it. See the Visitor pattern.

Parameters:

visitor - the visitor to accept.

getStartDate

public Date getStartDate()

Gets the date at which the trigger's scheduling should start. Null means no explicit starting date and the first fire of the trigger will be done according to the triggering definition. It may or not be the first actual fire time of the trigger, depending on the type of this trigger and its triggering definition. However, the first actual fire time won't be done after this date.

Returns:

the job trigger's scheduling start date.

triggerEvery

public static JobTrigger triggerEvery(int time,
                                      TimeUnit unit)

Creates a job trigger that will fire a job execution every the specified time.

Returns:

a job trigger whose the triggering is scheduled periodically at a given time.

triggerAt

public static JobTrigger triggerAt(String cron)
                            throws ParseException

Creates a job trigger that will fire a job execution at given moments in time, defined by the specified cron expression. For more information on the syntax of the cron expression, please see the CronJobTrigger documentation.

Parameters:

cron - the Unix cron-like expression.

Returns:

a job trigger whose the triggering is scheduled at given moments in time.

Throws:

ParseException - if the specified cron expression isn't valid.

See Also:

CronJobTrigger

startAt

public JobTrigger startAt(Date startDate)

Sets the date at which the trigger's scheduling should start. May or may not be the first actual fire time of the trigger. However the first actual first time will not be before this date.

Parameters:

startDate - the job trigger's scheduling start date.