Class ThreadPoolTaskScheduler

java.lang.Object

org.springframework.util.CustomizableThreadCreator

org.springframework.scheduling.concurrent.CustomizableThreadFactory

org.springframework.scheduling.concurrent.ExecutorConfigurationSupport

org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler

All Implemented Interfaces:

Serializable, Executor, ThreadFactory, EventListener, Aware, BeanNameAware, DisposableBean, InitializingBean, ApplicationContextAware, ApplicationListener<ContextClosedEvent>, Lifecycle, Phased, SmartLifecycle, AsyncTaskExecutor, TaskExecutor, SchedulingTaskExecutor, TaskScheduler

public class ThreadPoolTaskScheduler
extends ExecutorConfigurationSupport
implements AsyncTaskExecutor, SchedulingTaskExecutor, TaskScheduler

A standard implementation of Spring's TaskScheduler interface, wrapping a native ScheduledThreadPoolExecutor and providing all applicable configuration options for it. The default number of scheduler threads is 1; a higher number can be configured through setPoolSize(int).

This is Spring's traditional scheduler variant, staying as close as possible to ScheduledExecutorService semantics. Task execution happens on the scheduler thread(s) rather than on separate execution threads. As a consequence, a ScheduledFuture handle (for example, from schedule(Runnable, Instant)) represents the actual completion of the provided task (or series of repeated tasks).

Since:

3.0

Author:

Juergen Hoeller, Mark Fisher

See Also:

• setPoolSize(int)
• setRemoveOnCancelPolicy(boolean)
• setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean)
• setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean)
• ExecutorConfigurationSupport.setThreadFactory(ThreadFactory)
• setErrorHandler(ErrorHandler)
• ThreadPoolTaskExecutor
• SimpleAsyncTaskScheduler
• Serialized Form

Field Summary

Fields inherited from class ExecutorConfigurationSupport

DEFAULT_PHASE, logger

Fields inherited from interface AsyncTaskExecutor

TIMEOUT_IMMEDIATE, TIMEOUT_INDEFINITE

Constructor Summary

Constructors

Constructor	Description
ThreadPoolTaskScheduler()

Method Summary

Modifier and Type	Method	Description
protected ScheduledExecutorService	createExecutor(int poolSize, ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)	Create a new ScheduledExecutorService instance.
void	execute(Runnable task)	Execute the given task.
int	getActiveCount()	Return the number of currently active threads.
Clock	getClock()	Return the clock to use for scheduling purposes.
int	getPoolSize()	Return the current pool size.
ScheduledExecutorService	getScheduledExecutor()	Return the underlying ScheduledExecutorService for native access.
ScheduledThreadPoolExecutor	getScheduledThreadPoolExecutor()	Return the underlying ScheduledThreadPoolExecutor, if available.
protected ExecutorService	initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)	Create the target ExecutorService instance.
boolean	isRemoveOnCancelPolicy()	Deprecated. in favor of direct getScheduledThreadPoolExecutor() access
ScheduledFuture<?>	schedule(Runnable task, Instant startTime)	Schedule the given Runnable, invoking it at the specified execution time.
@Nullable ScheduledFuture<?>	schedule(Runnable task, Trigger trigger)	Schedule the given Runnable, invoking it whenever the trigger indicates a next execution time.
ScheduledFuture<?>	scheduleAtFixedRate(Runnable task, Duration period)	Schedule the given Runnable, starting as soon as possible and invoking it with the given period.
ScheduledFuture<?>	scheduleAtFixedRate(Runnable task, Instant startTime, Duration period)	Schedule the given Runnable, invoking it at the specified execution time and subsequently with the given period.
ScheduledFuture<?>	scheduleWithFixedDelay(Runnable task, Duration delay)	Schedule the given Runnable, starting as soon as possible and invoking it with the given delay between the completion of one execution and the start of the next.
ScheduledFuture<?>	scheduleWithFixedDelay(Runnable task, Instant startTime, Duration delay)	Schedule the given Runnable, invoking it at the specified execution time and subsequently with the given delay between the completion of one execution and the start of the next.
void	setClock(Clock clock)	Set the clock to use for scheduling purposes.
void	setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean flag)	Set whether to continue existing periodic tasks even when this executor has been shutdown.
void	setErrorHandler(ErrorHandler errorHandler)	Set a custom ErrorHandler strategy.
void	setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean flag)	Set whether to execute existing delayed tasks even when this executor has been shutdown.
void	setPoolSize(int poolSize)	Set the ScheduledExecutorService's pool size.
void	setRemoveOnCancelPolicy(boolean flag)	Set the remove-on-cancel mode on ScheduledThreadPoolExecutor.
void	setTaskDecorator(TaskDecorator taskDecorator)	Specify a custom TaskDecorator to be applied to any Runnable about to be executed.
Future<?>	submit(Runnable task)	Submit a Runnable task for execution, receiving a Future representing that task.
<T> Future<T>	submit(Callable<T> task)	Submit a Callable task for execution, receiving a Future representing that task.

Methods inherited from class ExecutorConfigurationSupport

afterExecute, afterPropertiesSet, beforeExecute, cancelRemainingTask, destroy, getPhase, initialize, initiateEarlyShutdown, initiateShutdown, isRunning, onApplicationEvent, setAcceptTasksAfterContextClose, setApplicationContext, setAwaitTerminationMillis, setAwaitTerminationSeconds, setBeanName, setPhase, setRejectedExecutionHandler, setThreadFactory, setThreadNamePrefix, setVirtualThreads, setWaitForTasksToCompleteOnShutdown, shutdown, start, stop, stop

Methods inherited from class CustomizableThreadFactory

newThread

Methods inherited from class CustomizableThreadCreator

createThread, getDefaultThreadNamePrefix, getThreadGroup, getThreadNamePrefix, getThreadPriority, isDaemon, nextThreadName, setDaemon, setThreadGroup, setThreadGroupName, setThreadPriority

Methods inherited from class Object

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

Methods inherited from interface ApplicationListener

supportsAsyncExecution

Methods inherited from interface AsyncTaskExecutor

execute, submitCompletable, submitCompletable

Methods inherited from interface SchedulingTaskExecutor

prefersShortLivedTasks

Methods inherited from interface SmartLifecycle

isAutoStartup, isPauseable

Methods inherited from interface TaskScheduler

schedule, scheduleAtFixedRate, scheduleAtFixedRate, scheduleWithFixedDelay, scheduleWithFixedDelay

Constructor Details

ThreadPoolTaskScheduler

public ThreadPoolTaskScheduler()

Method Details

setPoolSize

public void setPoolSize(int poolSize)

Set the ScheduledExecutorService's pool size. Default is 1.

This setting can be modified at runtime, for example through JMX.

setRemoveOnCancelPolicy

public void setRemoveOnCancelPolicy(boolean flag)

Set the remove-on-cancel mode on ScheduledThreadPoolExecutor.

Default is false. If set to true, the target executor will be switched into remove-on-cancel mode (if possible).

This setting can be modified at runtime, for example through JMX.

See Also:

• ScheduledThreadPoolExecutor.setRemoveOnCancelPolicy(boolean)

setContinueExistingPeriodicTasksAfterShutdownPolicy

public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean flag)

Set whether to continue existing periodic tasks even when this executor has been shutdown.

Default is false. If set to true, the target executor will be switched into continuing periodic tasks (if possible).

This setting can be modified at runtime, for example through JMX.

Since:

5.3.9

See Also:

• ScheduledThreadPoolExecutor.setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean)

setExecuteExistingDelayedTasksAfterShutdownPolicy

public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean flag)

Set whether to execute existing delayed tasks even when this executor has been shutdown.

Default is true. If set to false, the target executor will be switched into dropping remaining tasks (if possible).

This setting can be modified at runtime, for example through JMX.

Since:

5.3.9

See Also:

• ScheduledThreadPoolExecutor.setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean)

setTaskDecorator

public void setTaskDecorator(TaskDecorator taskDecorator)

Specify a custom TaskDecorator to be applied to any Runnable about to be executed.

Note that such a decorator is not being applied to the user-supplied Runnable/Callable but rather to the scheduled execution callback (a wrapper around the user-supplied task).

The primary use case is to set some execution context around the task's invocation, or to provide some monitoring/statistics for task execution.

Since:

6.2

setErrorHandler

public void setErrorHandler(ErrorHandler errorHandler)

Set a custom ErrorHandler strategy.

setClock

public void setClock(Clock clock)

Set the clock to use for scheduling purposes.

The default clock is the system clock for the default time zone.

Since:

5.3

See Also:

• Clock.systemDefaultZone()

getClock

public Clock getClock()

Description copied from interface: TaskScheduler

Return the clock to use for scheduling purposes.

Specified by:

getClock in interface TaskScheduler

See Also:

• Clock.systemDefaultZone()

initializeExecutor

protected ExecutorService initializeExecutor(ThreadFactory threadFactory,
 RejectedExecutionHandler rejectedExecutionHandler)

Description copied from class: ExecutorConfigurationSupport

Create the target ExecutorService instance. Called by afterPropertiesSet.

Specified by: