Package org.springframework.context.event

Class AbstractApplicationEventMulticaster

java.lang.Object

org.springframework.context.event.AbstractApplicationEventMulticaster

All Implemented Interfaces:

org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanClassLoaderAware, org.springframework.beans.factory.BeanFactoryAware, ApplicationEventMulticaster

Direct Known Subclasses:

SimpleApplicationEventMulticaster

public abstract class AbstractApplicationEventMulticaster
extends Object
implements ApplicationEventMulticaster, org.springframework.beans.factory.BeanClassLoaderAware, org.springframework.beans.factory.BeanFactoryAware

Abstract implementation of the ApplicationEventMulticaster interface, providing the basic listener registration facility.

Doesn't permit multiple instances of the same listener by default, as it keeps listeners in a linked Set. The collection class used to hold ApplicationListener objects can be overridden through the "collectionClass" bean property.

Implementing ApplicationEventMulticaster's actual ApplicationEventMulticaster.multicastEvent(org.springframework.context.ApplicationEvent) method is left to subclasses. SimpleApplicationEventMulticaster simply multicasts all events to all registered listeners, invoking them in the calling thread. Alternative implementations could be more sophisticated in those respects.

Since:

1.2.3

Author:

Juergen Hoeller, Stephane Nicoll

See Also:

• getApplicationListeners(ApplicationEvent, ResolvableType)
• SimpleApplicationEventMulticaster

Constructor Summary

Constructors

Constructor	Description
AbstractApplicationEventMulticaster()

Method Summary

Modifier and Type	Method	Description
void	addApplicationListener(ApplicationListener<?> listener)	Add a listener to be notified of all events.
void	addApplicationListenerBean(String listenerBeanName)	Add a listener bean to be notified of all events.
protected Collection<ApplicationListener<?>>	getApplicationListeners()	Return a Collection containing all ApplicationListeners.
protected Collection<ApplicationListener<?>>	getApplicationListeners(ApplicationEvent event, org.springframework.core.ResolvableType eventType)	Return a Collection of ApplicationListeners matching the given event type.
void	removeAllListeners()	Remove all listeners registered with this multicaster.
void	removeApplicationListener(ApplicationListener<?> listener)	Remove a listener from the notification list.
void	removeApplicationListenerBean(String listenerBeanName)	Remove a listener bean from the notification list.
void	removeApplicationListenerBeans(Predicate<String> predicate)	Remove all matching listener beans from the set of registered listener bean names (referring to bean classes which in turn implement the ApplicationListener interface directly).
void	removeApplicationListeners(Predicate<ApplicationListener<?>> predicate)	Remove all matching listeners from the set of registered ApplicationListener instances (which includes adapter classes such as ApplicationListenerMethodAdapter, e.g.
void	setBeanClassLoader(ClassLoader classLoader)
void	setBeanFactory(org.springframework.beans.factory.BeanFactory beanFactory)
protected boolean	supportsEvent(Class<?> listenerType, org.springframework.core.ResolvableType eventType)	Filter a listener early through checking its generically declared event type before trying to instantiate it.
protected boolean	supportsEvent(ApplicationListener<?> listener, org.springframework.core.ResolvableType eventType, Class<?> sourceType)	Determine whether the given listener supports the given event.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.context.event.ApplicationEventMulticaster

multicastEvent, multicastEvent

Constructor Details

AbstractApplicationEventMulticaster

public AbstractApplicationEventMulticaster()

Method Details

setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)

Specified by:

setBeanClassLoader in interface org.springframework.beans.factory.BeanClassLoaderAware

setBeanFactory

public void setBeanFactory(org.springframework.beans.factory.BeanFactory beanFactory)

Specified by:

setBeanFactory in interface org.springframework.beans.factory.BeanFactoryAware

addApplicationListener

public void addApplicationListener(ApplicationListener<?> listener)

Description copied from interface: ApplicationEventMulticaster

Add a listener to be notified of all events.

Specified by:

addApplicationListener in interface ApplicationEventMulticaster

Parameters:

listener - the listener to add

See Also:

• ApplicationEventMulticaster.removeApplicationListener(ApplicationListener)
• ApplicationEventMulticaster.removeApplicationListeners(Predicate)

addApplicationListenerBean

public void addApplicationListenerBean(String listenerBeanName)

Description copied from interface: ApplicationEventMulticaster

Add a listener bean to be notified of all events.

Specified by:

addApplicationListenerBean in interface ApplicationEventMulticaster

Parameters:

listenerBeanName - the name of the listener bean to add

See Also:

• ApplicationEventMulticaster.removeApplicationListenerBean(String)
• ApplicationEventMulticaster.removeApplicationListenerBeans(Predicate)

removeApplicationListener

public void removeApplicationListener(ApplicationListener<?> listener)

Description copied from interface: ApplicationEventMulticaster

Remove a listener from the notification list.

Specified by:

removeApplicationListener in interface ApplicationEventMulticaster

Parameters:

listener - the listener to remove

See Also:

• ApplicationEventMulticaster.addApplicationListener(ApplicationListener)
• ApplicationEventMulticaster.removeApplicationListeners(Predicate)

removeApplicationListenerBean

public void removeApplicationListenerBean(String listenerBeanName)

Description copied from interface: ApplicationEventMulticaster

Remove a listener bean from the notification list.

Specified by:

removeApplicationListenerBean in interface ApplicationEventMulticaster

Parameters:

listenerBeanName - the name of the listener bean to remove

See Also:

• ApplicationEventMulticaster.addApplicationListenerBean(String)
• ApplicationEventMulticaster.removeApplicationListenerBeans(Predicate)

removeApplicationListeners

public void removeApplicationListeners(Predicate<ApplicationListener<?>> predicate)

Description copied from interface: ApplicationEventMulticaster

Remove all matching listeners from the set of registered ApplicationListener instances (which includes adapter classes such as ApplicationListenerMethodAdapter, e.g. for annotated EventListener methods).

Note: This just applies to instance registrations, not to listeners registered by bean name.

Specified by:

removeApplicationListeners in interface ApplicationEventMulticaster

Parameters:

predicate - the predicate to identify listener instances to remove, e.g. checking SmartApplicationListener.getListenerId()

See Also:

• ApplicationEventMulticaster.addApplicationListener(ApplicationListener)
• ApplicationEventMulticaster.removeApplicationListener(ApplicationListener)

removeApplicationListenerBeans

public void removeApplicationListenerBeans(Predicate<String> predicate)

Description copied from interface: ApplicationEventMulticaster

Remove all matching listener beans from the set of registered listener bean names (referring to bean classes which in turn implement the ApplicationListener interface directly).

Note: This just applies to bean name registrations, not to programmatically registered ApplicationListener instances.

Specified by:

removeApplicationListenerBeans in interface ApplicationEventMulticaster

Parameters:

predicate - the predicate to identify listener bean names to remove

See Also:

• ApplicationEventMulticaster.addApplicationListenerBean(String)
• ApplicationEventMulticaster.removeApplicationListenerBean(String)

removeAllListeners

public void removeAllListeners()

Description copied from interface: ApplicationEventMulticaster

Remove all listeners registered with this multicaster.

After a remove call, the multicaster will perform no action on event notification until new listeners are registered.

Specified by:

removeAllListeners in interface ApplicationEventMulticaster

See Also:

• ApplicationEventMulticaster.removeApplicationListeners(Predicate)

getApplicationListeners

protected Collection<ApplicationListener<?>> getApplicationListeners()

Return a Collection containing all ApplicationListeners.

Returns:

a Collection of ApplicationListeners

See Also:

• ApplicationListener

getApplicationListeners

protected Collection<ApplicationListener<?>> getApplicationListeners(ApplicationEvent event,
 org.springframework.core.ResolvableType eventType)

Return a Collection of ApplicationListeners matching the given event type. Non-matching listeners get excluded early.

Parameters:

event - the event to be propagated. Allows for excluding non-matching listeners early, based on cached matching information.

eventType - the event type

Returns:

a Collection of ApplicationListeners

See Also:

• ApplicationListener

supportsEvent

protected boolean supportsEvent(Class<?> listenerType,
 org.springframework.core.ResolvableType eventType)

Filter a listener early through checking its generically declared event type before trying to instantiate it.

If this method returns true for a given listener as a first pass, the listener instance will get retrieved and fully evaluated through a supportsEvent(ApplicationListener, ResolvableType, Class) call afterwards.

Parameters:

listenerType - the listener's type as determined by the BeanFactory

eventType - the event type to check

Returns:

whether the given listener should be included in the candidates for the given event type

supportsEvent

protected boolean supportsEvent(ApplicationListener<?> listener,
 org.springframework.core.ResolvableType eventType,
 @Nullable
 Class<?> sourceType)

Determine whether the given listener supports the given event.

The default implementation detects the SmartApplicationListener and GenericApplicationListener interfaces. In case of a standard ApplicationListener, a GenericApplicationListenerAdapter will be used to introspect the generically declared type of the target listener.

Parameters:

listener - the target listener to check

eventType - the event type to check against

sourceType - the source type to check against

Returns:

whether the given listener should be included in the candidates for the given event type