org.springframework.scheduling.backportconcurrent
Class ScheduledExecutorTask

java.lang.Object
  org.springframework.scheduling.backportconcurrent.ScheduledExecutorTask

public class ScheduledExecutorTask
extends Object

JavaBean that describes a scheduled executor task, consisting of the Runnable and a delay plus period. The period needs to be specified; there is no point in a default for it.

The JSR-166 backport ScheduledExecutorService does not offer more sophisticated scheduling options such as cron expressions. Consider using Quartz for such advanced needs.

Note that the ScheduledExecutorService mechanism uses a Runnable instance that is shared between repeated executions, in contrast to Quartz which creates a new Job instance for each execution.

This class is analogous to the ScheduledTimerTask class for the JDK 1.3 Timer facility.

Since:

2.0.3

Author:

Juergen Hoeller

See Also:

ScheduledExecutorService.scheduleWithFixedDelay(java.lang.Runnable, long, long, edu.emory.mathcs.backport.java.util.concurrent.TimeUnit), ScheduledExecutorService.scheduleAtFixedRate(java.lang.Runnable, long, long, edu.emory.mathcs.backport.java.util.concurrent.TimeUnit), ScheduledTimerTask

Constructor Summary

ScheduledExecutorTask()
Create a new ScheduledExecutorTask, to be populated via bean properties.

ScheduledExecutorTask(Runnable executorTask)
Create a new ScheduledExecutorTask, with default one-time execution without delay.

ScheduledExecutorTask(Runnable executorTask, long delay)
Create a new ScheduledExecutorTask, with default one-time execution with the given delay.

ScheduledExecutorTask(Runnable executorTask, long delay, long period, boolean fixedRate)
Create a new ScheduledExecutorTask.

Method Summary

long	getDelay() Return the delay before starting the job for the first time.
long	getPeriod() Return the period between repeated task executions.
Runnable	getRunnable() Return the Runnable to schedule as executor task.
edu.emory.mathcs.backport.java.util.concurrent.TimeUnit	getTimeUnit() Return the time unit for the delay and period values.
boolean	isFixedRate() Return whether to schedule as fixed-rate execution.
boolean	isOneTimeTask() Is this task only ever going to execute once?
void	setDelay(long delay) Set the delay before starting the task for the first time, in milliseconds.
void	setFixedRate(boolean fixedRate) Set whether to schedule as fixed-rate execution, rather than fixed-delay execution.
void	setPeriod(long period) Set the period between repeated task executions, in milliseconds.
void	setRunnable(Runnable executorTask) Set the Runnable to schedule as executor task.
void	setTimeUnit(edu.emory.mathcs.backport.java.util.concurrent.TimeUnit timeUnit) Specify the time unit for the delay and period values.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScheduledExecutorTask

public ScheduledExecutorTask()

Create a new ScheduledExecutorTask, to be populated via bean properties.

See Also:

setDelay(long), setPeriod(long), setFixedRate(boolean)

ScheduledExecutorTask

public ScheduledExecutorTask(Runnable executorTask)

Create a new ScheduledExecutorTask, with default one-time execution without delay.

Parameters:

executorTask - the Runnable to schedule

ScheduledExecutorTask

public ScheduledExecutorTask(Runnable executorTask,
                             long delay)

Create a new ScheduledExecutorTask, with default one-time execution with the given delay.

Parameters:

executorTask - the Runnable to schedule

delay - the delay before starting the task for the first time (ms)

ScheduledExecutorTask

public ScheduledExecutorTask(Runnable executorTask,
                             long delay,
                             long period,
                             boolean fixedRate)

Create a new ScheduledExecutorTask.

Parameters:

executorTask - the Runnable to schedule

delay - the delay before starting the task for the first time (ms)

period - the period between repeated task executions (ms)

fixedRate - whether to schedule as fixed-rate execution

Method Detail

setRunnable

public void setRunnable(Runnable executorTask)

Set the Runnable to schedule as executor task.

getRunnable

public Runnable getRunnable()

Return the Runnable to schedule as executor task.

setDelay

public void setDelay(long delay)

Set the delay before starting the task for the first time, in milliseconds. Default is 0, immediately starting the task after successful scheduling.

getDelay

public long getDelay()

Return the delay before starting the job for the first time.

setPeriod

public void setPeriod(long period)

Set the period between repeated task executions, in milliseconds.

Default is -1, leading to one-time execution. In case of a positive value, the task will be executed repeatedly, with the given interval inbetween executions.

Note that the semantics of the period value vary between fixed-rate and fixed-delay execution.

Note: A period of 0 (for example as fixed delay) is not supported, simply because edu.emory.mathcs.backport.java.util.concurrent.ScheduledExecutorService itself does not support it. Hence a value of 0 will be treated as one-time execution; however, that value should never be specified explicitly in the first place!

See Also:

setFixedRate(boolean), isOneTimeTask(), ScheduledExecutorService.scheduleWithFixedDelay(java.lang.Runnable, long, long, edu.emory.mathcs.backport.java.util.concurrent.TimeUnit)

getPeriod

public long getPeriod()

Return the period between repeated task executions.

isOneTimeTask

public boolean isOneTimeTask()

Is this task only ever going to execute once?

Returns:

true if this task is only ever going to execute once

See Also:

getPeriod()

setTimeUnit

public void setTimeUnit(edu.emory.mathcs.backport.java.util.concurrent.TimeUnit timeUnit)

Specify the time unit for the delay and period values. Default is milliseconds (TimeUnit.MILLISECONDS).

See Also:

TimeUnit.MILLISECONDS, TimeUnit.SECONDS

getTimeUnit

public edu.emory.mathcs.backport.java.util.concurrent.TimeUnit getTimeUnit()

Return the time unit for the delay and period values.

setFixedRate

public void setFixedRate(boolean fixedRate)

Set whether to schedule as fixed-rate execution, rather than fixed-delay execution. Default is "false", that is, fixed delay.

See ScheduledExecutorService javadoc for details on those execution modes.

See Also:

ScheduledExecutorService.scheduleWithFixedDelay(java.lang.Runnable, long, long, edu.emory.mathcs.backport.java.util.concurrent.TimeUnit), ScheduledExecutorService.scheduleAtFixedRate(java.lang.Runnable, long, long, edu.emory.mathcs.backport.java.util.concurrent.TimeUnit)

isFixedRate

public boolean isFixedRate()

Return whether to schedule as fixed-rate execution.