Package org.springframework.scheduling.concurrent

Class ThreadPoolExecutorFactoryBean

java.lang.Object

org.springframework.util.CustomizableThreadCreator

org.springframework.scheduling.concurrent.CustomizableThreadFactory

org.springframework.scheduling.concurrent.ExecutorConfigurationSupport

org.springframework.scheduling.concurrent.ThreadPoolExecutorFactoryBean

All Implemented Interfaces:

Serializable, ThreadFactory, EventListener, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.FactoryBean<ExecutorService>, org.springframework.beans.factory.InitializingBean, ApplicationContextAware, ApplicationListener<ContextClosedEvent>, Lifecycle, Phased, SmartLifecycle

public class ThreadPoolExecutorFactoryBean
extends ExecutorConfigurationSupport
implements org.springframework.beans.factory.FactoryBean<ExecutorService>

JavaBean that allows for configuring a ThreadPoolExecutor in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds", "queueCapacity" properties) and exposing it as a bean reference of its native ExecutorService type.

The default configuration is a core pool size of 1, with unlimited max pool size and unlimited queue capacity. This is roughly equivalent to Executors.newSingleThreadExecutor(), sharing a single thread for all tasks. Setting "queueCapacity" to 0 mimics Executors.newCachedThreadPool(), with immediate scaling of threads in the pool to a potentially very high number. Consider also setting a "maxPoolSize" at that point, as well as possibly a higher "corePoolSize" (see also the "allowCoreThreadTimeOut" mode of scaling).

For an alternative, you may set up a ThreadPoolExecutor instance directly using constructor injection, or use a factory method definition that points to the Executors class. This is strongly recommended in particular for common @Bean methods in configuration classes, where this FactoryBean variant would force you to return the FactoryBean type instead of the actual Executor type.

If you need a timing-based ScheduledExecutorService instead, consider ScheduledExecutorFactoryBean.

Since:

3.0

Author:

Juergen Hoeller

See Also:

• ExecutorService
• Executors
• ThreadPoolExecutor
• Serialized Form

Field Summary

Fields inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport

DEFAULT_PHASE, logger

Fields inherited from interface org.springframework.beans.factory.FactoryBean

OBJECT_TYPE_ATTRIBUTE

Constructor Summary

Constructors

Constructor	Description
ThreadPoolExecutorFactoryBean()

Method Summary

Modifier and Type	Method	Description
protected ThreadPoolExecutor	createExecutor(int corePoolSize, int maxPoolSize, int keepAliveSeconds, BlockingQueue<Runnable> queue, ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)	Create a new instance of ThreadPoolExecutor or a subclass thereof.
protected BlockingQueue<Runnable>	createQueue(int queueCapacity)	Create the BlockingQueue to use for the ThreadPoolExecutor.
ExecutorService	getObject()
Class<? extends ExecutorService>	getObjectType()
protected ExecutorService	initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)	Create the target ExecutorService instance.
protected void	initiateEarlyShutdown()	Early shutdown signal: do not trigger further tasks, let existing tasks complete before hitting the actual destruction step in the ExecutorConfigurationSupport.shutdown() method.
boolean	isSingleton()
void	setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut)	Specify whether to allow core threads to time out.
void	setCorePoolSize(int corePoolSize)	Set the ThreadPoolExecutor's core pool size.
void	setExposeUnconfigurableExecutor(boolean exposeUnconfigurableExecutor)	Specify whether this FactoryBean should expose an unconfigurable decorator for the created executor.
void	setKeepAliveSeconds(int keepAliveSeconds)	Set the ThreadPoolExecutor's keep-alive seconds.
void	setMaxPoolSize(int maxPoolSize)	Set the ThreadPoolExecutor's maximum pool size.
void	setPrestartAllCoreThreads(boolean prestartAllCoreThreads)	Specify whether to start all core threads, causing them to idly wait for work.
void	setQueueCapacity(int queueCapacity)	Set the capacity for the ThreadPoolExecutor's BlockingQueue.
void	setStrictEarlyShutdown(boolean defaultEarlyShutdown)	Specify whether to initiate an early shutdown signal on context close, disposing all idle threads and rejecting further task submissions.

Methods inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport

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

Methods inherited from class org.springframework.scheduling.concurrent.CustomizableThreadFactory

newThread

Methods inherited from class org.springframework.util.CustomizableThreadCreator

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.context.ApplicationListener

supportsAsyncExecution

Methods inherited from interface org.springframework.context.SmartLifecycle

isAutoStartup

Constructor Details

ThreadPoolExecutorFactoryBean

public ThreadPoolExecutorFactoryBean()

Method Details

setCorePoolSize

public void setCorePoolSize(int corePoolSize)

Set the ThreadPoolExecutor's core pool size. Default is 1.

setMaxPoolSize

public void setMaxPoolSize(int maxPoolSize)

Set the ThreadPoolExecutor's maximum pool size. Default is Integer.MAX_VALUE.

setKeepAliveSeconds

public void setKeepAliveSeconds(int keepAliveSeconds)

Set the ThreadPoolExecutor's keep-alive seconds. Default is 60.

setQueueCapacity

public void setQueueCapacity(int queueCapacity)

Set the capacity for the ThreadPoolExecutor's BlockingQueue. Default is Integer.MAX_VALUE.

Any positive value will lead to a LinkedBlockingQueue instance; any other value will lead to a SynchronousQueue instance.

See Also:

• LinkedBlockingQueue
• SynchronousQueue

setAllowCoreThreadTimeOut

public void setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut)

Specify whether to allow core threads to time out. This enables dynamic growing and shrinking even in combination with a non-zero queue (since the max pool size will only grow once the queue is full).

Default is "false".

See Also:

• ThreadPoolExecutor.allowCoreThreadTimeOut(boolean)

setPrestartAllCoreThreads

public void setPrestartAllCoreThreads(boolean prestartAllCoreThreads)

Specify whether to start all core threads, causing them to idly wait for work.

Default is "false".

Since:

5.3.14

See Also:

• ThreadPoolExecutor.prestartAllCoreThreads()

setStrictEarlyShutdown

public void setStrictEarlyShutdown(boolean defaultEarlyShutdown)

Specify whether to initiate an early shutdown signal on context close, disposing all idle threads and rejecting further task submissions.

Default is "false". See ThreadPoolTaskExecutor.setStrictEarlyShutdown(boolean) for details.

Since:

6.1.4

See Also:

• ExecutorConfigurationSupport.initiateShutdown()

setExposeUnconfigurableExecutor

public void setExposeUnconfigurableExecutor(boolean exposeUnconfigurableExecutor)

Specify whether this FactoryBean should expose an unconfigurable decorator for the created executor.

Default is "false", exposing the raw executor as bean reference. Switch this flag to "true" to strictly prevent clients from modifying the executor's configuration.

See Also:

• Executors.unconfigurableExecutorService(java.util.concurrent.ExecutorService)

initializeExecutor

protected ExecutorService initializeExecutor(ThreadFactory threadFactory,
 RejectedExecutionHandler rejectedExecutionHandler)

Description copied from class: ExecutorConfigurationSupport

Create the target ExecutorService instance. Called by afterPropertiesSet.

Specified by:

initializeExecutor in class ExecutorConfigurationSupport

Parameters:

threadFactory - the ThreadFactory to use

rejectedExecutionHandler - the RejectedExecutionHandler to use

Returns:

a new ExecutorService instance

See Also:

• ExecutorConfigurationSupport.afterPropertiesSet()

createExecutor

protected ThreadPoolExecutor createExecutor(int corePoolSize,
 int maxPoolSize,
 int keepAliveSeconds,
 BlockingQueue<Runnable> queue,
 ThreadFactory threadFactory,
 RejectedExecutionHandler rejectedExecutionHandler)

Create a new instance of ThreadPoolExecutor or a subclass thereof.

The default implementation creates a standard ThreadPoolExecutor. Can be overridden to provide custom ThreadPoolExecutor subclasses.

Parameters:

corePoolSize - the specified core pool size

maxPoolSize - the specified maximum pool size

keepAliveSeconds - the specified keep-alive time in seconds

queue - the BlockingQueue to use

threadFactory - the ThreadFactory to use

rejectedExecutionHandler - the RejectedExecutionHandler to use

Returns:

a new ThreadPoolExecutor instance

See Also:

• ExecutorConfigurationSupport.afterPropertiesSet()

createQueue

protected BlockingQueue<Runnable> createQueue(int queueCapacity)

Create the BlockingQueue to use for the ThreadPoolExecutor.

A LinkedBlockingQueue instance will be created for a positive capacity value; a SynchronousQueue else.

Parameters:

queueCapacity - the specified queue capacity

Returns:

the BlockingQueue instance

See Also:

• LinkedBlockingQueue
• SynchronousQueue

initiateEarlyShutdown

protected void initiateEarlyShutdown()

Description copied from class: ExecutorConfigurationSupport

Early shutdown signal: do not trigger further tasks, let existing tasks complete before hitting the actual destruction step in the ExecutorConfigurationSupport.shutdown() method. This goes along with a coordinated lifecycle stop phase.

Called from ExecutorConfigurationSupport.onApplicationEvent(ContextClosedEvent) if no indications for a late shutdown have been determined, that is, if the "acceptTasksAfterContextClose and "waitForTasksToCompleteOnShutdown" flags have not been set.

The default implementation calls ExecutorConfigurationSupport.initiateShutdown().

Overrides:

initiateEarlyShutdown in class ExecutorConfigurationSupport

See Also:

• ExecutorConfigurationSupport.initiateShutdown()

getObject

@Nullable
public ExecutorService getObject()

Specified by:

getObject in interface org.springframework.beans.factory.FactoryBean<ExecutorService>

getObjectType

public Class<? extends ExecutorService> getObjectType()

Specified by:

getObjectType in interface org.springframework.beans.factory.FactoryBean<ExecutorService>

isSingleton

public boolean isSingleton()

Specified by:

isSingleton in interface org.springframework.beans.factory.FactoryBean<ExecutorService>