public class

ThreadPoolTaskExecutor

extends ExecutorConfigurationSupport
implements SchedulingTaskExecutor
java.lang.Object
   ↳ org.springframework.util.CustomizableThreadCreator
     ↳ org.springframework.scheduling.concurrent.CustomizableThreadFactory
       ↳ org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
         ↳ org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor

Class Overview

JavaBean that allows for configuring a JDK 1.5 java.util.concurrent.ThreadPoolExecutor in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds", "queueCapacity" properties) and exposing it as a Spring TaskExecutor. This class is also well suited for management and monitoring (e.g. through JMX), providing several useful attributes: "corePoolSize", "maxPoolSize", "keepAliveSeconds" (all supporting updates at runtime); "poolSize", "activeCount" (for introspection only).

For an alternative, you may set up a ThreadPoolExecutor instance directly using constructor injection, or use a factory method definition that points to the JDK 1.5 java.util.concurrent.Executors class. To expose such a raw Executor as a Spring TaskExecutor, simply wrap it with a ConcurrentTaskExecutor adapter.

NOTE: This class implements Spring's TaskExecutor interface as well as the JDK 1.5 Executor interface, with the former being the primary interface, the other just serving as secondary convenience. For this reason, the exception handling follows the TaskExecutor contract rather than the Executor contract, in particular regarding the TaskRejectedException.

If you prefer native ExecutorService exposure instead, consider ThreadPoolExecutorFactoryBean as an alternative to this class.

See Also

Summary

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Inherited Constants
From interface org.springframework.core.task.AsyncTaskExecutor
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Inherited Fields
From class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
Public Constructors
ThreadPoolTaskExecutor()
Public Methods
void execute(Runnable task, long startTimeout)
Execute the given task.
void execute(Runnable task)
Execute the given task.
int getActiveCount()
Return the number of currently active threads.
int getCorePoolSize()
Return the ThreadPoolExecutor's core pool size.
int getKeepAliveSeconds()
Return the ThreadPoolExecutor's keep-alive seconds.
int getMaxPoolSize()
Return the ThreadPoolExecutor's maximum pool size.
int getPoolSize()
Return the current pool size.
ThreadPoolExecutor getThreadPoolExecutor()
Return the underlying ThreadPoolExecutor for native access.
boolean prefersShortLivedTasks()
This task executor prefers short-lived work units.
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 setKeepAliveSeconds(int keepAliveSeconds)
Set the ThreadPoolExecutor's keep-alive seconds.
void setMaxPoolSize(int maxPoolSize)
Set the ThreadPoolExecutor's maximum pool size.
void setQueueCapacity(int queueCapacity)
Set the capacity for the ThreadPoolExecutor's BlockingQueue.
<T> Future<T> submit(Callable<T> task)
Submit a Callable task for execution, receiving a Future representing that task.
Future<?> submit(Runnable task)
Submit a Runnable task for execution, receiving a Future representing that task.
Protected Methods
BlockingQueue<Runnable> createQueue(int queueCapacity)
Create the BlockingQueue to use for the ThreadPoolExecutor.
ExecutorService initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)
Create the target ExecutorService instance.
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Inherited Methods
From class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
From class org.springframework.scheduling.concurrent.CustomizableThreadFactory
From class org.springframework.util.CustomizableThreadCreator
From class java.lang.Object
From interface java.util.concurrent.Executor
From interface java.util.concurrent.ThreadFactory
From interface org.springframework.beans.factory.BeanNameAware
From interface org.springframework.beans.factory.DisposableBean
From interface org.springframework.beans.factory.InitializingBean
From interface org.springframework.core.task.AsyncTaskExecutor
From interface org.springframework.core.task.TaskExecutor
From interface org.springframework.scheduling.SchedulingTaskExecutor

Public Constructors

public ThreadPoolTaskExecutor ()

Public Methods

public void execute (Runnable task, long startTimeout)

Execute the given task.

Parameters
task the Runnable to execute (never null)
startTimeout the time duration (milliseconds) within which the task is supposed to start. This is intended as a hint to the executor, allowing for preferred handling of immediate tasks. Typical values are TIMEOUT_IMMEDIATE or TIMEOUT_INDEFINITE (the default as used by execute(Runnable)).

public void execute (Runnable task)

Execute the given task.

The call might return immediately if the implementation uses an asynchronous execution strategy, or might block in the case of synchronous execution.

Parameters
task the Runnable to execute (never null)

public int getActiveCount ()

Return the number of currently active threads.

See Also

public int getCorePoolSize ()

Return the ThreadPoolExecutor's core pool size.

public int getKeepAliveSeconds ()

Return the ThreadPoolExecutor's keep-alive seconds.

public int getMaxPoolSize ()

Return the ThreadPoolExecutor's maximum pool size.

public int getPoolSize ()

Return the current pool size.

See Also

public ThreadPoolExecutor getThreadPoolExecutor ()

Return the underlying ThreadPoolExecutor for native access.

Returns
  • the underlying ThreadPoolExecutor (never null)
Throws
IllegalStateException if the ThreadPoolTaskExecutor hasn't been initialized yet

public boolean prefersShortLivedTasks ()

This task executor prefers short-lived work units.

Returns
  • true if this TaskExecutor prefers short-lived tasks

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". Note that this feature is only available on Java 6 or above. On Java 5, consider switching to the backport-concurrent version of ThreadPoolTaskExecutor which also supports this feature.

See Also

public void setCorePoolSize (int corePoolSize)

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

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

public void setKeepAliveSeconds (int keepAliveSeconds)

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

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

public void setMaxPoolSize (int maxPoolSize)

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

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

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
  • java.util.concurrent.LinkedBlockingQueue
  • java.util.concurrent.SynchronousQueue

public Future<T> submit (Callable<T> task)

Submit a Callable task for execution, receiving a Future representing that task. The Future will return the Callable's result upon completion.

Parameters
task the Callable to execute (never null)
Returns
  • a Future representing pending completion of the task

public Future<?> submit (Runnable task)

Submit a Runnable task for execution, receiving a Future representing that task. The Future will return a null result upon completion.

Parameters
task the Runnable to execute (never null)
Returns
  • a Future representing pending completion of the task

Protected Methods

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
  • java.util.concurrent.LinkedBlockingQueue
  • java.util.concurrent.SynchronousQueue

protected ExecutorService initializeExecutor (ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)

Create the target ExecutorService instance. Called by afterPropertiesSet.

Parameters
threadFactory the ThreadFactory to use
rejectedExecutionHandler the RejectedExecutionHandler to use
Returns
  • a new ExecutorService instance