Class PeriodicTrigger
- java.lang.Object
- org.springframework.scheduling.support.PeriodicTrigger
- All Implemented Interfaces:
Trigger
public class PeriodicTrigger extends Object implements Trigger
A trigger for periodic task execution. The period may be applied as either fixed-rate or fixed-delay, and an initial delay value may also be configured. The default initial delay is 0, and the default behavior is fixed-delay (i.e. the interval between successive executions is measured from eachcompletion time). To measure the interval between the scheduledstart time of each execution instead, set the 'fixedRate' property totrue
.Note that the TaskScheduler interface already defines methods for scheduling tasks at fixed-rate or with fixed-delay. Both also support an optional value for the initial delay. Those methods should be used directly whenever possible. The value of this Trigger implementation is that it can be used within components that rely on the Trigger abstraction. For example, it may be convenient to allow periodic triggers, cron-based triggers, and even custom Trigger implementations to be used interchangeably.
- Since:
- 3.0
- Author:
- Mark Fisher
Constructor Summary
Constructors Constructor Description PeriodicTrigger(long period)
Create a trigger with the given period in milliseconds.PeriodicTrigger(long period, TimeUnit timeUnit)
Create a trigger with the given period and time unit.
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
equals(Object obj)
int
hashCode()
Date
nextExecutionTime(TriggerContext triggerContext)
Returns the time after which a task should run again.void
setFixedRate(boolean fixedRate)
Specify whether the periodic interval should be measured between the scheduled start times rather than between actual completion times.void
setInitialDelay(long initialDelay)
Specify the delay for the initial execution.
Constructor Detail
PeriodicTrigger
public PeriodicTrigger(long period)
Create a trigger with the given period in milliseconds.
PeriodicTrigger
public PeriodicTrigger(long period, TimeUnit timeUnit)
Create a trigger with the given period and time unit. The time unit will apply not only to the period but also to any 'initialDelay' value, if configured on this Trigger later viasetInitialDelay(long)
.
Method Detail
setInitialDelay
public void setInitialDelay(long initialDelay)
Specify the delay for the initial execution. It will be evaluated in terms of this trigger'sTimeUnit
. If no time unit was explicitly provided upon instantiation, the default is milliseconds.
setFixedRate
public void setFixedRate(boolean fixedRate)
Specify whether the periodic interval should be measured between the scheduled start times rather than between actual completion times. The latter, "fixed delay" behavior, is the default.
nextExecutionTime
public Date nextExecutionTime(TriggerContext triggerContext)
Returns the time after which a task should run again.- Specified by:
nextExecutionTime
in interfaceTrigger
- Parameters:
triggerContext
- context object encapsulating last execution times and last completion time- Returns:
- the next execution time as defined by the trigger, or
null
if the trigger won't fire anymore