The Spring Framework

## org.springframework.scheduling.backportconcurrent
Class ThreadPoolTaskExecutor

    java.lang.Object
      org.springframework.util.CustomizableThreadCreator
          org.springframework.scheduling.backportconcurrent.CustomizableThreadFactory
              org.springframework.scheduling.backportconcurrent.ThreadPoolTaskExecutor

All Implemented Interfaces:
  edu.emory.mathcs.backport.java.util.concurrent.Executor, edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory, BeanNameAware, DisposableBean, InitializingBean, TaskExecutor, SchedulingTaskExecutor

    public class ThreadPoolTaskExecutor

extends CustomizableThreadFactory
implements SchedulingTaskExecutor, edu.emory.mathcs.backport.java.util.concurrent.Executor, BeanNameAware, InitializingBean, DisposableBean

JavaBean that allows for configuring a JSR-166 backport `ThreadPoolExecutor` in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds", "queueCapacity" properties), exposing it as a Spring `TaskExecutor`. This is an alternative to configuring a ThreadPoolExecutor instance directly using constructor injection, with a separate `ConcurrentTaskExecutor` adapter wrapping it.

For any custom needs, in particular for defining a `ScheduledThreadPoolExecutor`, it is recommended to use a straight definition of the Executor instance or a factory method definition that points to the JSR-166 backport `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 JSR-166 `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`.

Since:
  2.0.3
Author:
  Juergen Hoeller
See Also:
  `TaskExecutor`, `Executor`, `ThreadPoolExecutor`, `ScheduledThreadPoolExecutor`, `Executors`, `ConcurrentTaskExecutor`

Field Summary
`protected Log` `logger`

Constructor Summary
`ThreadPoolTaskExecutor()`

Method Summary
`void` `afterPropertiesSet()` Calls `initialize()` after the container applied all property values.
`protected edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue` `createQueue(int queueCapacity)` Create the BlockingQueue to use for the ThreadPoolExecutor.
`void` `destroy()` Calls `shutdown` when the BeanFactory destroys the task executor instance.
`void` `execute(Runnable task)` Implementation of both the JSR-166 backport Executor interface and the Spring TaskExecutor interface, delegating to the ThreadPoolExecutor instance.
`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.
`edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor` `getThreadPoolExecutor()` Return the underlying ThreadPoolExecutor for native access.
`void` `initialize()` Creates the BlockingQueue and the ThreadPoolExecutor.
`boolean` `prefersShortLivedTasks()` This task executor prefers short-lived work units.
`void` `setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut)` Specify whether to allow core threads to time out.
`void` `setBeanName(String name)` Set the name of the bean in the bean factory that created this bean.
`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` `setRejectedExecutionHandler(edu.emory.mathcs.backport.java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)` Set the RejectedExecutionHandler to use for the ThreadPoolExecutor.
`void` `setThreadFactory(edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory threadFactory)` Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool.
`void` `setThreadNamePrefix(String threadNamePrefix)` Specify the prefix to use for the names of newly created threads.
`void` `setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown)` Set whether to wait for scheduled tasks to complete on shutdown.
`void` `shutdown()` Perform a shutdown on the ThreadPoolExecutor.

Methods inherited from class org.springframework.scheduling.backportconcurrent.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`

Field Detail

### logger

    protected final Log logger

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.

### 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". Note that this feature is only available on backport-concurrent 3.0 or above (based on the code in Java 6).

  See Also:
    `ThreadPoolExecutor.allowCoreThreadTimeOut(boolean)`

### 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`

### setThreadFactory

    public void setThreadFactory(edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory threadFactory)

  Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool.

  Default is this executor itself (i.e. the factory that this executor inherits from). See `CustomizableThreadCreator`'s javadoc for available bean properties.

  See Also:
    `CustomizableThreadCreator.setThreadPriority(int)`, `CustomizableThreadCreator.setDaemon(boolean)`

### setRejectedExecutionHandler

    public void setRejectedExecutionHandler(edu.emory.mathcs.backport.java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)

  Set the RejectedExecutionHandler to use for the ThreadPoolExecutor. Default is the ThreadPoolExecutor's default abort policy.

  See Also:
    `ThreadPoolExecutor.AbortPolicy`

### setWaitForTasksToCompleteOnShutdown

    public void setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown)

  Set whether to wait for scheduled tasks to complete on shutdown.

  Default is "false". Switch this to "true" if you prefer fully completed tasks at the expense of a longer shutdown phase.

  See Also:
    `ThreadPoolExecutor.shutdown()`, `ThreadPoolExecutor.shutdownNow()`

### setThreadNamePrefix

    public void setThreadNamePrefix(String threadNamePrefix)

  Description copied from class: `CustomizableThreadCreator`
  Specify the prefix to use for the names of newly created threads. Default is "SimpleAsyncTaskExecutor-".

  Overrides:
    `setThreadNamePrefix` in class `CustomizableThreadCreator`

### setBeanName

    public void setBeanName(String name)

  Description copied from interface: `BeanNameAware`
  Set the name of the bean in the bean factory that created this bean.

  Invoked after population of normal bean properties but before an init callback such as `InitializingBean.afterPropertiesSet()` or a custom init-method.

  Specified by:
    `setBeanName` in interface `BeanNameAware`
  Parameters:
    `name` - the name of the bean in the factory. Note that this name is the actual bean name used in the factory, which may differ from the originally specified name: in particular for inner bean names, the actual bean name might have been made unique through appending "#..." suffixes. Use the `BeanFactoryUtils.originalBeanName(String)` method to extract the original bean name (without suffix), if desired.

### afterPropertiesSet

    public void afterPropertiesSet()

  Calls `initialize()` after the container applied all property values.

  Specified by:
    `afterPropertiesSet` in interface `InitializingBean`
  See Also:
    `initialize()`

### initialize

    public void initialize()

  Creates the BlockingQueue and the ThreadPoolExecutor.

  See Also:
    `createQueue(int)`

### createQueue

    protected edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue 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 edu.emory.mathcs.backport.java.util.concurrent.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

### execute

    public void execute(Runnable task)

  Implementation of both the JSR-166 backport Executor interface and the Spring TaskExecutor interface, delegating to the ThreadPoolExecutor instance.

  Specified by:
    `execute` in interface `edu.emory.mathcs.backport.java.util.concurrent.Executor`
  Specified by:
    `execute` in interface `TaskExecutor`
  Parameters:
    `task` - the `Runnable` to execute (never `null`)
  See Also:
    `Executor.execute(Runnable)`, `TaskExecutor.execute(Runnable)`

### 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

### 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()`

### destroy

    public void destroy()

  Calls `shutdown` when the BeanFactory destroys the task executor instance.

  Specified by:
    `destroy` in interface `DisposableBean`
  See Also:
    `shutdown()`

### shutdown

    public void shutdown()

  Perform a shutdown on the ThreadPoolExecutor.

  See Also:
    `ThreadPoolExecutor.shutdown()`

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