Spring Framework

org.springframework.scheduling.concurrent
Class ScheduledExecutorFactoryBean

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.ScheduledExecutorFactoryBean
All Implemented Interfaces:
java.io.Serializable, java.util.concurrent.ThreadFactory, Aware, BeanNameAware, DisposableBean, FactoryBean<java.util.concurrent.ScheduledExecutorService>, InitializingBean

public class ScheduledExecutorFactoryBean
extends ExecutorConfigurationSupport
implements FactoryBean<java.util.concurrent.ScheduledExecutorService>

FactoryBean that sets up a JDK 1.5 ScheduledExecutorService (by default: a ScheduledThreadPoolExecutor) 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.

WARNING: Runnables submitted via a native ScheduledExecutorService are removed from the execution schedule once they throw an exception. If you would prefer to continue execution after such an exception, switch this FactoryBean's "continueScheduledExecutionAfterException" property to "true".

Since:
2.0
Author:
Juergen Hoeller
See Also:
setPoolSize(int), ExecutorConfigurationSupport.setThreadFactory(java.util.concurrent.ThreadFactory), ScheduledExecutorTask, ScheduledExecutorService, ScheduledThreadPoolExecutor, Serialized Form

Field Summary
 
Fields inherited from class org.springframework.scheduling.concurrent.ExecutorConfigurationSupport
logger
 
Constructor Summary
ScheduledExecutorFactoryBean()
           
 
Method Summary
protected  java.util.concurrent.ScheduledExecutorService createExecutor(int poolSize, java.util.concurrent.ThreadFactory threadFactory, java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)
          Create a new ScheduledExecutorService instance.
 java.util.concurrent.ScheduledExecutorService getObject()
          Return an instance (possibly shared or independent) of the object managed by this factory.
 java.lang.Class<? extends java.util.concurrent.ScheduledExecutorService> getObjectType()
          Return the type of object that this FactoryBean creates, or null if not known in advance.
protected  java.lang.Runnable getRunnableToSchedule(ScheduledExecutorTask task)
          Determine the actual Runnable to schedule for the given task.
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)?
protected  void registerTasks(ScheduledExecutorTask[] tasks, java.util.concurrent.ScheduledExecutorService executor)
          Register the specified ScheduledExecutorTasks on the given ScheduledExecutorService.
 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 setScheduledExecutorTasks(ScheduledExecutorTask[] scheduledExecutorTasks)
          Register a list of ScheduledExecutorTask objects with the ScheduledExecutorService that this FactoryBean creates.
 
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
 

Constructor Detail

ScheduledExecutorFactoryBean

public ScheduledExecutorFactoryBean()
Method Detail

setPoolSize

public void setPoolSize(int poolSize)
Set the ScheduledExecutorService's pool size. Default is 1.


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)

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()

createExecutor

protected java.util.concurrent.ScheduledExecutorService createExecutor(int poolSize,
                                                                       java.util.concurrent.ThreadFactory threadFactory,
                                                                       java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)
Create a new ScheduledExecutorService instance.

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:
ExecutorConfigurationSupport.afterPropertiesSet(), ScheduledThreadPoolExecutor

registerTasks

protected void registerTasks(ScheduledExecutorTask[] tasks,
                             java.util.concurrent.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 java.lang.Runnable getRunnableToSchedule(ScheduledExecutorTask task)
Determine the actual Runnable to schedule for the given task.

Wraps the task's Runnable in a DelegatingErrorHandlingRunnable that will catch and log the Exception. If necessary, it will suppress the Exception according to the "continueScheduledExecutionAfterException" flag.

Parameters:
task - the ScheduledExecutorTask to schedule
Returns:
the actual Runnable to schedule (may be a decorator)

getObject

public java.util.concurrent.ScheduledExecutorService 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<java.util.concurrent.ScheduledExecutorService>
Returns:
an instance of the bean (can be null)
See Also:
FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<? extends java.util.concurrent.ScheduledExecutorService> 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.ScheduledExecutorService>
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.ScheduledExecutorService>
Returns:
whether the exposed object is a singleton
See Also:
FactoryBean.getObject(), SmartFactoryBean.isPrototype()

Spring Framework