public class

ThreadPoolExecutorFactoryBean

extends ExecutorConfigurationSupport
implements DisposableBean FactoryBean<T> InitializingBean
java.lang.Object
   ↳ org.springframework.util.CustomizableThreadCreator
     ↳ org.springframework.scheduling.concurrent.CustomizableThreadFactory
       ↳ org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
         ↳ org.springframework.scheduling.concurrent.ThreadPoolExecutorFactoryBean

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 bean reference of its native java.util.concurrent.ExecutorService type.

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.

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

See Also

Summary

[Expand]
Inherited Fields
From class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
Public Constructors
ThreadPoolExecutorFactoryBean()
Public Methods
ExecutorService getObject()
Return an instance (possibly shared or independent) of the object managed by this factory.
Class<? extends ExecutorService> getObjectType()
Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean isSingleton()
Is the object managed by this factory a singleton? That is, will getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory.

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 setQueueCapacity(int queueCapacity)
Set the capacity for the ThreadPoolExecutor's BlockingQueue.
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.
[Expand]
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.ThreadFactory
From interface org.springframework.beans.factory.BeanNameAware
From interface org.springframework.beans.factory.DisposableBean
From interface org.springframework.beans.factory.FactoryBean
From interface org.springframework.beans.factory.InitializingBean

Public Constructors

public ThreadPoolExecutorFactoryBean ()

Public Methods

public ExecutorService getObject ()

Return an instance (possibly shared or independent) of the object managed by this factory.

As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Returns
  • an instance of the bean (can be null)
Throws
Exception

public Class<? extends ExecutorService> getObjectType ()

Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Returns
  • the type of object that this FactoryBean creates, or null if not known at the time of the call

public boolean isSingleton ()

Is the object managed by this factory a singleton? That is, will getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Returns
  • whether the exposed object is a singleton

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.

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 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.

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

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