org.springframework.scheduling.concurrent
Class ScheduledExecutorFactoryBean

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

All Implemented Interfaces:

DisposableBean, FactoryBean, InitializingBean

public class ScheduledExecutorFactoryBean
extends Object
implements FactoryBean, 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.
boolean	isSingleton() Is the bean managed by this factory a singleton or a prototype?
protected void	registerTasks(ScheduledExecutorTask[] tasks, ScheduledExecutorService executor) Register the specified ScheduledExecutorTasks on the given ScheduledExecutorService.
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.

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

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)

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

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.

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.ScheduledThreadPoolExecutor(int, java.util.concurrent.ThreadFactory, java.util.concurrent.RejectedExecutionHandler)

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.

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 bean managed by this factory a singleton or a prototype? 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.

Specified by:

isSingleton in interface FactoryBean

Returns:

if this bean is a singleton

See Also:

FactoryBean.getObject()

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()