Spring Framework

org.springframework.scheduling.concurrent
Class ThreadPoolExecutorFactoryBean

java.lang.Object
  extended by org.springframework.util.CustomizableThreadCreator
      extended by org.springframework.scheduling.concurrent.CustomizableThreadFactory
          extended by org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
              extended by org.springframework.scheduling.concurrent.ThreadPoolExecutorFactoryBean
All Implemented Interfaces:
java.io.Serializable, java.util.concurrent.ThreadFactory, Aware, BeanNameAware, DisposableBean, FactoryBean<java.util.concurrent.ExecutorService>, InitializingBean

public class ThreadPoolExecutorFactoryBean
extends ExecutorConfigurationSupport
implements FactoryBean<java.util.concurrent.ExecutorService>, InitializingBean, DisposableBean

JavaBean that allows for configuring a JDK 1.5 ThreadPoolExecutor in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds", "queueCapacity" properties) and exposing it as a bean reference of its native 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 Executors class.

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

Since:
3.0
Author:
Juergen Hoeller
See Also:
ExecutorService, Executors, ThreadPoolExecutor, Serialized Form

Field Summary
 
Fields inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
logger
 
Constructor Summary
ThreadPoolExecutorFactoryBean()
           
 
Method Summary
protected  java.util.concurrent.BlockingQueue<java.lang.Runnable> createQueue(int queueCapacity)
          Create the BlockingQueue to use for the ThreadPoolExecutor.
 java.util.concurrent.ExecutorService getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 java.lang.Class<? extends java.util.concurrent.ExecutorService> getObjectType()
          Return the type of object that this FactoryBean creates, or null if not known in advance.
protected  java.util.concurrent.ExecutorService initializeExecutor(java.util.concurrent.ThreadFactory threadFactory, java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)
          Create the target ExecutorService instance.
 boolean isSingleton()
          Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?
 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.
 
Methods inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
afterPropertiesSet, destroy, initialize, 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.beans.factory.InitializingBean
afterPropertiesSet
 
Methods inherited from interface org.springframework.beans.factory.DisposableBean
destroy
 

Constructor Detail

ThreadPoolExecutorFactoryBean

public ThreadPoolExecutorFactoryBean()
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.


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.


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.


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 Java 6 or above. On Java 5, consider switching to the backport-concurrent version of ThreadPoolTaskExecutor which also supports this feature.

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

setExposeUnconfigurableExecutor

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.

See Also:
Executors.unconfigurableScheduledExecutorService(java.util.concurrent.ScheduledExecutorService)

initializeExecutor

protected java.util.concurrent.ExecutorService initializeExecutor(java.util.concurrent.ThreadFactory threadFactory,
                                                                  java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)
Description copied from class: ExecutorConfigurationSupport
Create the target ExecutorService instance. Called by afterPropertiesSet.

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 java.util.concurrent.BlockingQueue<java.lang.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

getObject

public java.util.concurrent.ExecutorService getObject()
                                               throws java.lang.Exception
Description copied from interface: FactoryBean
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.

Specified by:
getObject in interface FactoryBean<java.util.concurrent.ExecutorService>
Returns:
an instance of the bean (can be null)
Throws:
java.lang.Exception - in case of creation errors
See Also:
FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<? extends java.util.concurrent.ExecutorService> getObjectType()
Description copied from interface: FactoryBean
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.

Specified by:
getObjectType in interface FactoryBean<java.util.concurrent.ExecutorService>
Returns:
the type of object that this FactoryBean creates, or null if not known at the time of the call
See Also:
ListableBeanFactory.getBeansOfType(java.lang.Class)

isSingleton

public boolean isSingleton()
Description copied from interface: FactoryBean
Is the object managed by this factory a singleton? That is, will FactoryBean.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 SmartFactoryBean.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.

Specified by:
isSingleton in interface FactoryBean<java.util.concurrent.ExecutorService>
Returns:
whether the exposed object is a singleton
See Also:
FactoryBean.getObject(), SmartFactoryBean.isPrototype()

Spring Framework