org.springframework.scheduling.concurrent
Class ScheduledExecutorFactoryBean

java.lang.Object
  org.springframework.scheduling.concurrent.ScheduledExecutorFactoryBean

All Implemented Interfaces:

BeanNameAware, DisposableBean, FactoryBean, InitializingBean

public class ScheduledExecutorFactoryBean
extends Object
implements FactoryBean, BeanNameAware, InitializingBean, DisposableBean

FactoryBean that sets up a JDK 1.5 ScheduledExecutorService (by default: ScheduledThreadPoolExecutor as implementation) and exposes it for bean references.

Allows for registration of ScheduledExecutorTasks, automatically starting the ScheduledExecutorService on initialization and cancelling it on destruction of the context. In scenarios that just require static registration of tasks at startup, there is no need to access the ScheduledExecutorService instance itself in application code.

Note that ScheduledExecutorService uses a Runnable instance that is shared between repeated executions, in contrast to Quartz which instantiates a new Job for each execution.

This class is analogous to the TimerFactoryBean class for the JDK 1.3 Timer facility.

Since:

2.0

Author:

Juergen Hoeller

See Also:

ScheduledExecutorTask, ScheduledExecutorService, ScheduledThreadPoolExecutor, TimerFactoryBean

Field Summary

protected Log

logger

Constructor Summary

ScheduledExecutorFactoryBean()

Method Summary

void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected ScheduledExecutorService	createExecutor(int poolSize, ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) Create a new ScheduledExecutorService instance.
void	destroy() Cancel the ScheduledExecutorService on bean factory shutdown, stopping all scheduled tasks.
Object	getObject() Return an instance (possibly shared or independent) of the object managed by this factory.
Class	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
protected Runnable	getRunnableToSchedule(ScheduledExecutorTask task) Determine the actual Runnable to schedule for the given task.
boolean	isSingleton() Is the object managed by this factory a singleton?
protected void	registerTasks(ScheduledExecutorTask[] tasks, ScheduledExecutorService executor) Register the specified ScheduledExecutorTasks on the given ScheduledExecutorService.
void	setBeanName(String name) Set the name of the bean in the bean factory that created this bean.
void	setContinueScheduledExecutionAfterException(boolean continueScheduledExecutionAfterException) Specify whether to continue the execution of a scheduled task after it threw an exception.
void	setExposeUnconfigurableExecutor(boolean exposeUnconfigurableExecutor) Specify whether this FactoryBean should expose an unconfigurable decorator for the created executor.
void	setPoolSize(int poolSize) Set the ScheduledExecutorService's pool size.
void	setRejectedExecutionHandler(RejectedExecutionHandler rejectedExecutionHandler) Set the RejectedExecutionHandler to use for the ThreadPoolExecutor.
void	setScheduledExecutorTasks(ScheduledExecutorTask[] scheduledExecutorTasks) Register a list of ScheduledExecutorTask objects with the ScheduledExecutorService that this FactoryBean creates.
void	setThreadFactory(ThreadFactory threadFactory) Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool.
void	setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown) Set whether to wait for scheduled tasks to complete on shutdown.

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

ScheduledExecutorFactoryBean

public ScheduledExecutorFactoryBean()

Method Detail

setPoolSize

public void setPoolSize(int poolSize)

Set the ScheduledExecutorService's pool size. Default is 1.

setThreadFactory

public void setThreadFactory(ThreadFactory threadFactory)

Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool. Default is the ThreadPoolExecutor's default thread factory.

See Also:

Executors.defaultThreadFactory()

setRejectedExecutionHandler

public void setRejectedExecutionHandler(RejectedExecutionHandler rejectedExecutionHandler)

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

See Also:

ThreadPoolExecutor.AbortPolicy

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)

setScheduledExecutorTasks

public void setScheduledExecutorTasks(ScheduledExecutorTask[] scheduledExecutorTasks)

Register a list of ScheduledExecutorTask objects with the ScheduledExecutorService that this FactoryBean creates. Depending on each ScheduledExecutorTask's settings, it will be registered via one of ScheduledExecutorService's schedule methods.

See Also:

ScheduledExecutorService.schedule(java.lang.Runnable, long, java.util.concurrent.TimeUnit), ScheduledExecutorService.scheduleWithFixedDelay(java.lang.Runnable, long, long, java.util.concurrent.TimeUnit), ScheduledExecutorService.scheduleAtFixedRate(java.lang.Runnable, long, long, java.util.concurrent.TimeUnit)

setContinueScheduledExecutionAfterException

public void setContinueScheduledExecutionAfterException(boolean continueScheduledExecutionAfterException)

Specify whether to continue the execution of a scheduled task after it threw an exception.

Default is "false", matching the native behavior of a ScheduledExecutorService. Switch this flag to "true" for exception-proof execution of each task, continuing scheduled execution as in the case of successful execution.

See Also:

ScheduledExecutorService.scheduleAtFixedRate(java.lang.Runnable, long, long, java.util.concurrent.TimeUnit)

setWaitForTasksToCompleteOnShutdown

public void setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown)

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

Default is "true". Switch this to "false" if you prefer a shorter shutdown phase over fully completed tasks.

NOTE: The default will change to "false" as of Spring 2.1, for consistency with the defaults in the Quartz support.

See Also:

ExecutorService.shutdown(), ExecutorService.shutdownNow()

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()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

createExecutor

protected ScheduledExecutorService createExecutor(int poolSize,
                                                  ThreadFactory threadFactory,
                                                  RejectedExecutionHandler rejectedExecutionHandler)

Create a new ScheduledExecutorService instance. Called by afterPropertiesSet.

The default implementation creates a ScheduledThreadPoolExecutor. Can be overridden in subclasses to provide custom ScheduledExecutorService instances.

Parameters:

poolSize - the specified pool size

threadFactory - the ThreadFactory to use

rejectedExecutionHandler - the RejectedExecutionHandler to use

Returns:

a new ScheduledExecutorService instance

See Also:

afterPropertiesSet(), ScheduledThreadPoolExecutor

registerTasks

protected void registerTasks(ScheduledExecutorTask[] tasks,
                             ScheduledExecutorService executor)

Register the specified ScheduledExecutorTasks on the given ScheduledExecutorService.

Parameters:

tasks - the specified ScheduledExecutorTasks (never empty)

executor - the ScheduledExecutorService to register the tasks on.

getRunnableToSchedule

protected Runnable getRunnableToSchedule(ScheduledExecutorTask task)

Determine the actual Runnable to schedule for the given task.

Wraps the task's Runnable in a DelegatingExceptionProofRunnable if necessary, according to the "continueScheduledExecutionAfterException" flag.

Parameters:

task - the ScheduledExecutorTask to schedule

Returns:

the actual Runnable to schedule (may be a decorator)

getObject

public Object getObject()

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

Returns:

an instance of the bean (can be null)

See Also:

FactoryBeanNotInitializedException

getObjectType

public Class 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

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

Returns:

whether the exposed object is a singleton

See Also:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()

destroy

public void destroy()

Cancel the ScheduledExecutorService on bean factory shutdown, stopping all scheduled tasks.

Specified by:

destroy in interface DisposableBean

See Also:

ExecutorService.shutdown()