Class ThreadPoolTaskExecutor
- All Implemented Interfaces:
Serializable
,Executor
,ThreadFactory
,Aware
,BeanNameAware
,DisposableBean
,InitializingBean
,AsyncListenableTaskExecutor
,AsyncTaskExecutor
,TaskExecutor
,SchedulingTaskExecutor
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:
-
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
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionprotected void
cancelRemainingTask
(Runnable task) Cancel the given remaining task which never commended execution, as returned fromExecutorService.shutdownNow()
.protected BlockingQueue<Runnable>
createQueue
(int queueCapacity) Create the BlockingQueue to use for the ThreadPoolExecutor.void
Execute the giventask
.void
Execute the giventask
.int
Return the number of currently active threads.int
Return the ThreadPoolExecutor's core pool size.int
Return the ThreadPoolExecutor's keep-alive seconds.int
Return the ThreadPoolExecutor's maximum pool size.int
Return the current pool size.Return the underlying ThreadPoolExecutor for native access.protected ExecutorService
initializeExecutor
(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) Note: This method exposes anExecutorService
to its base class but stores the actualThreadPoolExecutor
handle internally.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
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
setTaskDecorator
(TaskDecorator taskDecorator) Specify a customTaskDecorator
to be applied to anyRunnable
about to be executed.Future<?>
Submit a Runnable task for execution, receiving a Future representing that task.<T> Future<T>
Submit a Callable task for execution, receiving a Future representing that task.submitListenable
(Runnable task) Submit aRunnable
task for execution, receiving aListenableFuture
representing that task.<T> ListenableFuture<T>
submitListenable
(Callable<T> task) Submit aCallable
task for execution, receiving aListenableFuture
representing that task.Methods inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
afterPropertiesSet, destroy, initialize, setAwaitTerminationMillis, 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
Methods inherited from interface org.springframework.scheduling.SchedulingTaskExecutor
prefersShortLivedTasks
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Constructor Details
-
ThreadPoolTaskExecutor
public ThreadPoolTaskExecutor()
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Method Details
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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.
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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 isInteger.MAX_VALUE
.This setting can be modified at runtime, for example through JMX.
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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.
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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 isInteger.MAX_VALUE
.Any positive value will lead to a LinkedBlockingQueue instance; any other value will lead to a SynchronousQueue instance.
- See Also:
-
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".
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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:
-
setTaskDecorator
Specify a customTaskDecorator
to be applied to anyRunnable
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 plainRunnable
execution viaexecute
calls. In case of#submit
calls, the exposedRunnable
will be aFutureTask
which does not propagate any exceptions; you might have to cast it and callFuture#get
to evaluate exceptions. See theThreadPoolExecutor#afterExecute
javadoc for an example of how to access exceptions in such aFuture
case.- Since:
- 4.3
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initializeExecutor
protected ExecutorService initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) Note: This method exposes anExecutorService
to its base class but stores the actualThreadPoolExecutor
handle internally. Do not override this method for replacing the executor, rather just for decorating itsExecutorService
handle or storing custom state.- Specified by:
initializeExecutor
in classExecutorConfigurationSupport
- Parameters:
threadFactory
- the ThreadFactory to userejectedExecutionHandler
- the RejectedExecutionHandler to use- Returns:
- a new ExecutorService instance
- See Also:
-
createQueue
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:
-
getThreadPoolExecutor
Return the underlying ThreadPoolExecutor for native access.- Returns:
- the underlying ThreadPoolExecutor (never
null
) - Throws:
IllegalStateException
- if the ThreadPoolTaskExecutor hasn't been initialized yet
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getPoolSize
public int getPoolSize()Return the current pool size.- See Also:
-
getActiveCount
public int getActiveCount()Return the number of currently active threads.- See Also:
-
execute
Description copied from interface:TaskExecutor
Execute the giventask
.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 interfaceExecutor
- Specified by:
execute
in interfaceTaskExecutor
- Parameters:
task
- theRunnable
to execute (nevernull
)
-
execute
Description copied from interface:AsyncTaskExecutor
Execute the giventask
.- Specified by:
execute
in interfaceAsyncTaskExecutor
- Parameters:
task
- theRunnable
to execute (nevernull
)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 areAsyncTaskExecutor.TIMEOUT_IMMEDIATE
orAsyncTaskExecutor.TIMEOUT_INDEFINITE
(the default as used byTaskExecutor.execute(Runnable)
).
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submit
Description copied from interface:AsyncTaskExecutor
Submit a Runnable task for execution, receiving a Future representing that task. The Future will return anull
result upon completion.- Specified by:
submit
in interfaceAsyncTaskExecutor
- Parameters:
task
- theRunnable
to execute (nevernull
)- Returns:
- a Future representing pending completion of the task
-
submit
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 interfaceAsyncTaskExecutor
- Parameters:
task
- theCallable
to execute (nevernull
)- Returns:
- a Future representing pending completion of the task
-
submitListenable
Description copied from interface:AsyncListenableTaskExecutor
Submit aRunnable
task for execution, receiving aListenableFuture
representing that task. The Future will return anull
result upon completion.- Specified by:
submitListenable
in interfaceAsyncListenableTaskExecutor
- Parameters:
task
- theRunnable
to execute (nevernull
)- Returns:
- a
ListenableFuture
representing pending completion of the task
-
submitListenable
Description copied from interface:AsyncListenableTaskExecutor
Submit aCallable
task for execution, receiving aListenableFuture
representing that task. The Future will return the Callable's result upon completion.- Specified by:
submitListenable
in interfaceAsyncListenableTaskExecutor
- Parameters:
task
- theCallable
to execute (nevernull
)- Returns:
- a
ListenableFuture
representing pending completion of the task
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cancelRemainingTask
Description copied from class:ExecutorConfigurationSupport
Cancel the given remaining task which never commended execution, as returned fromExecutorService.shutdownNow()
.- Overrides:
cancelRemainingTask
in classExecutorConfigurationSupport
- Parameters:
task
- the task to cancel (typically aRunnableFuture
)- See Also:
-