org.springframework.context.event

Class AbstractApplicationEventMulticaster

java.lang.Object

org.springframework.context.event.AbstractApplicationEventMulticaster

All Implemented Interfaces:

Aware, BeanClassLoaderAware, BeanFactoryAware, ApplicationEventMulticaster

Direct Known Subclasses:

SimpleApplicationEventMulticaster

public abstract class AbstractApplicationEventMulticaster
extends java.lang.Object
implements ApplicationEventMulticaster, BeanClassLoaderAware, 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 and Description
AbstractApplicationEventMulticaster()

Method Summary

Modifier and Type	Method and Description
void	addApplicationListener(ApplicationListener<?> listener) Add a listener to be notified of all events.
void	addApplicationListenerBean(java.lang.String listenerBeanName) Add a listener bean to be notified of all events.
protected java.util.Collection<ApplicationListener<?>>	getApplicationListeners() Return a Collection containing all ApplicationListeners.
protected java.util.Collection<ApplicationListener<?>>	getApplicationListeners(ApplicationEvent event, 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(java.lang.String listenerBeanName) Remove a listener bean from the notification list.
void	setBeanClassLoader(java.lang.ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
void	setBeanFactory(BeanFactory beanFactory) Callback that supplies the owning factory to a bean instance.
protected boolean	supportsEvent(ApplicationListener<?> listener, ResolvableType eventType, java.lang.Class<?> sourceType) Determine whether the given listener supports the given event.
protected boolean	supportsEvent(java.lang.Class<?> listenerType, ResolvableType eventType) Filter a listener early through checking its generically declared event type before trying to instantiate it.

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 Detail

AbstractApplicationEventMulticaster

public AbstractApplicationEventMulticaster()

Method Detail

setBeanClassLoader

public void setBeanClassLoader(java.lang.ClassLoader classLoader)

Description copied from interface: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:

setBeanClassLoader in interface BeanClassLoaderAware

Parameters:

classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

setBeanFactory

public void setBeanFactory(BeanFactory beanFactory)

Description copied from interface: BeanFactoryAware

Callback that supplies the owning factory to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean.afterPropertiesSet() or a custom init-method.

Specified by:

setBeanFactory in interface BeanFactoryAware

Parameters:

beanFactory - owning BeanFactory (never null). The bean can immediately call methods on the factory.

See Also:

BeanInitializationException

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

addApplicationListenerBean

public void addApplicationListenerBean(java.lang.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

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

removeApplicationListenerBean

public void removeApplicationListenerBean(java.lang.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 add

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 being registered.

Specified by:

removeAllListeners in interface ApplicationEventMulticaster

getApplicationListeners

protected java.util.Collection<ApplicationListener<?>> getApplicationListeners()

Return a Collection containing all ApplicationListeners.

Returns:

a Collection of ApplicationListeners

See Also:

ApplicationListener

getApplicationListeners

protected java.util.Collection<ApplicationListener<?>> getApplicationListeners(ApplicationEvent event,
                                                                               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(java.lang.Class<?> listenerType,
                                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,
                                ResolvableType eventType,
                                java.lang.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