public class ThreadPoolExecutorFactoryBean extends ExecutorConfigurationSupport implements FactoryBean<ExecutorService>, InitializingBean, DisposableBean
ThreadPoolExecutor
in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds",
"queueCapacity" properties) and exposing it as a bean reference of its native
ExecutorService type.
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).
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.
This is strongly recommended in particular for common @Bean methods in
configuration classes, where this FactoryBean variant would force you to
return the FactoryBean type instead of the actual Executor type.
If you need a timing-based ScheduledExecutorService
instead, consider ScheduledExecutorFactoryBean.
ExecutorService,
Executors,
ThreadPoolExecutor,
Serialized Formlogger| Constructor and Description |
|---|
ThreadPoolExecutorFactoryBean() |
| Modifier and Type | Method and Description |
|---|---|
protected ThreadPoolExecutor |
createExecutor(int corePoolSize,
int maxPoolSize,
int keepAliveSeconds,
BlockingQueue<Runnable> queue,
ThreadFactory threadFactory,
RejectedExecutionHandler rejectedExecutionHandler)
Create a new instance of
ThreadPoolExecutor or a subclass thereof. |
protected BlockingQueue<Runnable> |
createQueue(int queueCapacity)
Create the BlockingQueue to use for the ThreadPoolExecutor.
|
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. |
protected ExecutorService |
initializeExecutor(ThreadFactory threadFactory,
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.
|
afterPropertiesSet, cancelRemainingTask, destroy, initialize, setAwaitTerminationSeconds, setBeanName, setRejectedExecutionHandler, setThreadFactory, setThreadNamePrefix, setWaitForTasksToCompleteOnShutdown, shutdownnewThreadcreateThread, getDefaultThreadNamePrefix, getThreadGroup, getThreadNamePrefix, getThreadPriority, isDaemon, nextThreadName, setDaemon, setThreadGroup, setThreadGroupName, setThreadPriorityclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitafterPropertiesSetdestroypublic void setCorePoolSize(int corePoolSize)
public void setMaxPoolSize(int maxPoolSize)
Integer.MAX_VALUE.public void setKeepAliveSeconds(int keepAliveSeconds)
public void setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut)
Default is "false".
public void setQueueCapacity(int queueCapacity)
Integer.MAX_VALUE.
Any positive value will lead to a LinkedBlockingQueue instance; any other value will lead to a SynchronousQueue instance.
LinkedBlockingQueue,
SynchronousQueuepublic void setExposeUnconfigurableExecutor(boolean exposeUnconfigurableExecutor)
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.
protected ExecutorService initializeExecutor(ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)
ExecutorConfigurationSupportExecutorService instance.
Called by afterPropertiesSet.initializeExecutor in class ExecutorConfigurationSupportthreadFactory - the ThreadFactory to userejectedExecutionHandler - the RejectedExecutionHandler to useExecutorConfigurationSupport.afterPropertiesSet()protected ThreadPoolExecutor createExecutor(int corePoolSize, int maxPoolSize, int keepAliveSeconds, BlockingQueue<Runnable> queue, ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler)
ThreadPoolExecutor or a subclass thereof.
The default implementation creates a standard ThreadPoolExecutor.
Can be overridden to provide custom ThreadPoolExecutor subclasses.
corePoolSize - the specified core pool sizemaxPoolSize - the specified maximum pool sizekeepAliveSeconds - the specified keep-alive time in secondsqueue - the BlockingQueue to usethreadFactory - the ThreadFactory to userejectedExecutionHandler - the RejectedExecutionHandler to useExecutorConfigurationSupport.afterPropertiesSet()protected BlockingQueue<Runnable> createQueue(int queueCapacity)
A LinkedBlockingQueue instance will be created for a positive capacity value; a SynchronousQueue else.
queueCapacity - the specified queue capacityLinkedBlockingQueue,
SynchronousQueue@Nullable public ExecutorService getObject()
FactoryBeanAs 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.
getObject in interface FactoryBean<ExecutorService>null)FactoryBeanNotInitializedExceptionpublic Class<? extends ExecutorService> getObjectType()
FactoryBeannull 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.
getObjectType in interface FactoryBean<ExecutorService>null if not known at the time of the callListableBeanFactory.getBeansOfType(java.lang.Class<T>)public boolean isSingleton()
FactoryBeanFactoryBean.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.
The default implementation returns true, since a
FactoryBean typically manages a singleton instance.
isSingleton in interface FactoryBean<ExecutorService>FactoryBean.getObject(),
SmartFactoryBean.isPrototype()