java.lang.Object
- org.springframework.util.CustomizableThreadCreator
- - org.springframework.scheduling.concurrent.CustomizableThreadFactory
  - - org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
    - - org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor

All Implemented Interfaces:
Serializable, Executor, ThreadFactory, Aware, BeanNameAware, DisposableBean, InitializingBean, AsyncListenableTaskExecutor, AsyncTaskExecutor, TaskExecutor, SchedulingTaskExecutor
```
public class ThreadPoolTaskExecutor
extends ExecutorConfigurationSupport
implements AsyncListenableTaskExecutor, SchedulingTaskExecutor
```
JavaBean that allows for configuring a 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).
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).
NOTE: This class implements Spring's TaskExecutor interface as well as the 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.
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. To expose such a raw Executor as a Spring TaskExecutor, simply wrap it with a ConcurrentTaskExecutor adapter.
Since:
2.0
Author:
Juergen Hoeller
See Also:
TaskExecutor, ThreadPoolExecutor, ThreadPoolExecutorFactoryBean, ConcurrentTaskExecutor, Serialized Form

Field Summary
- Fields inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
  logger
- Fields inherited from interface org.springframework.core.task.AsyncTaskExecutor
  TIMEOUT_IMMEDIATE, TIMEOUT_INDEFINITE

Constructor Summary
Constructors
Constructor Description
ThreadPoolTaskExecutor()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected BlockingQueue<Runnable>`	`createQueue(int queueCapacity)`	Create the BlockingQueue to use for the ThreadPoolExecutor.
`void`	`execute(Runnable task)`	Execute the given `task`.
`void`	`execute(Runnable task, long startTimeout)`	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.
`protected ExecutorService`	`initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)`	Note: This method exposes an `ExecutorService` to its base class but stores the actual `ThreadPoolExecutor` handle internally.
`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.
`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.
`ListenableFuture<?>`	`submitListenable(Runnable task)`	Submit a `Runnable` task for execution, receiving a `ListenableFuture` representing that task.
`<T> ListenableFuture<T>`	`submitListenable(Callable<T> task)`	Submit a `Callable` task for execution, receiving a `ListenableFuture` representing that task.

Methods inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
afterPropertiesSet, destroy, initialize, setAwaitTerminationSeconds, setBeanName, setRejectedExecutionHandler, setThreadFactory, setThreadNamePrefix, setWaitForTasksToCompleteOnShutdown, shutdown

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

- Constructor Detail
  - ThreadPoolTaskExecutor
```
public ThreadPoolTaskExecutor()
```
- Method Detail
  - setCorePoolSize
```
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.
  - getCorePoolSize
```
public int getCorePoolSize()
```
    Return the ThreadPoolExecutor's core pool size.
  - setMaxPoolSize
```
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.
  - getMaxPoolSize
```
public int getMaxPoolSize()
```
    Return the ThreadPoolExecutor's maximum pool size.
  - setKeepAliveSeconds
```
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.
  - getKeepAliveSeconds
```
public int getKeepAliveSeconds()
```
    Return the ThreadPoolExecutor's keep-alive seconds.
  - 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)
  - 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 necessarily being applied to the user-supplied Runnable/Callable but rather to the actual execution callback (which may be 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.
    NOTE: Exception handling in TaskDecorator implementations is limited to plain Runnable execution via execute calls. In case of #submit calls, the exposed Runnable will be a FutureTask which does not propagate any exceptions; you might have to cast it and call Future#get to evaluate exceptions. See the ThreadPoolExecutor#afterExecute javadoc for an example of how to access exceptions in such a Future case.
    Since:
    4.3
  - initializeExecutor
```
protected ExecutorService initializeExecutor(ThreadFactory threadFactory,
                                             RejectedExecutionHandler rejectedExecutionHandler)
```
    Note: This method exposes an ExecutorService to its base class but stores the actual ThreadPoolExecutor handle internally. Do not override this method for replacing the executor, rather just for decorating its ExecutorService handle or storing custom state.
    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()
  - 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
  - getThreadPoolExecutor
```
public ThreadPoolExecutor getThreadPoolExecutor()
                                         throws IllegalStateException
```
    Return the underlying ThreadPoolExecutor for native access.
    Returns:
    the underlying ThreadPoolExecutor (never null)
    Throws:
    IllegalStateException - if the ThreadPoolTaskExecutor hasn't been initialized yet
  - getPoolSize
```
public int getPoolSize()
```
    Return the current pool size.
    See Also:
    ThreadPoolExecutor.getPoolSize()
  - getActiveCount
```
public int getActiveCount()
```
    Return the number of currently active threads.
    See Also:
    ThreadPoolExecutor.getActiveCount()
  - execute
```
public void execute(Runnable task)
```
    Description copied from interface: TaskExecutor
    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.
    Specified by:
    execute in interface Executor
    Specified by:
    execute in interface TaskExecutor
    Parameters:
    task - the Runnable to execute (never null)
  - execute
```
public void execute(Runnable task,
                    long startTimeout)
```
    Description copied from interface: AsyncTaskExecutor
    Execute the given task.
    Specified by:
    execute in interface AsyncTaskExecutor
    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 AsyncTaskExecutor.TIMEOUT_IMMEDIATE or AsyncTaskExecutor.TIMEOUT_INDEFINITE (the default as used by TaskExecutor.execute(Runnable)).
  - submit
```
public Future<?> submit(Runnable task)
```
    Description copied from interface: AsyncTaskExecutor
    Submit a Runnable task for execution, receiving a Future representing that task. The Future will return a null result upon completion.
    Specified by:
    submit in interface AsyncTaskExecutor
    Parameters:
    task - the Runnable to execute (never null)
    Returns:
    a Future representing pending completion of the task
  - submit
```
public <T> Future<T> submit(Callable<T> task)
```
    Description copied from interface: AsyncTaskExecutor
    Submit a Callable task for execution, receiving a Future representing that task. The Future will return the Callable's result upon completion.
    Specified by:
    submit in interface AsyncTaskExecutor
    Parameters:
    task - the Callable to execute (never null)
    Returns:
    a Future representing pending completion of the task
  - submitListenable
```
public ListenableFuture<?> submitListenable(Runnable task)
```
    Description copied from interface: AsyncListenableTaskExecutor
    Submit a Runnable task for execution, receiving a ListenableFuture representing that task. The Future will return a null result upon completion.
    Specified by:
    submitListenable in interface AsyncListenableTaskExecutor
    Parameters:
    task - the Runnable to execute (never null)
    Returns:
    a ListenableFuture representing pending completion of the task
  - submitListenable
```
public <T> ListenableFuture<T> submitListenable(Callable<T> task)
```
    Description copied from interface: AsyncListenableTaskExecutor
    Submit a Callable task for execution, receiving a ListenableFuture representing that task. The Future will return the Callable's result upon completion.
    Specified by:
    submitListenable in interface AsyncListenableTaskExecutor
    Parameters:
    task - the Callable to execute (never null)
    Returns:
    a ListenableFuture representing pending completion of the task
  - prefersShortLivedTasks
```
public boolean prefersShortLivedTasks()
```
    This task executor prefers short-lived work units.
    Specified by:
    prefersShortLivedTasks in interface SchedulingTaskExecutor
    Returns:
    true if this TaskExecutor prefers short-lived tasks

Class ThreadPoolTaskExecutor

Field Summary

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

Fields inherited from interface org.springframework.core.task.AsyncTaskExecutor

Constructor Summary

Method Summary

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

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

Methods inherited from class org.springframework.util.CustomizableThreadCreator

Methods inherited from class java.lang.Object

Constructor Detail

ThreadPoolTaskExecutor

Method Detail

setCorePoolSize

getCorePoolSize

setMaxPoolSize

getMaxPoolSize

setKeepAliveSeconds

getKeepAliveSeconds

setQueueCapacity

setAllowCoreThreadTimeOut

setTaskDecorator

initializeExecutor

createQueue

getThreadPoolExecutor

getPoolSize

getActiveCount

execute

execute

submit

submit

submitListenable

submitListenable

prefersShortLivedTasks