Class SourceFilteringListener

java.lang.Object

org.springframework.context.event.SourceFilteringListener

All Implemented Interfaces:

EventListener, ApplicationListener<ApplicationEvent>, GenericApplicationListener, SmartApplicationListener, org.springframework.core.Ordered

public class SourceFilteringListener
extends Object
implements GenericApplicationListener

ApplicationListener decorator that filters events from a specified event source, invoking its delegate listener for matching ApplicationEvent objects only.

Can also be used as base class, overriding the onApplicationEventInternal(ApplicationEvent) method instead of specifying a delegate listener.

Since:

2.0.5

Author:

Juergen Hoeller, Stephane Nicoll

Field Summary

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SourceFilteringListener(Object source)	Create a SourceFilteringListener for the given event source, expecting subclasses to override the onApplicationEventInternal(ApplicationEvent) method (instead of specifying a delegate listener).
	SourceFilteringListener(Object source, ApplicationListener<?> delegate)	Create a SourceFilteringListener for the given event source.

Method Summary

Modifier and Type	Method	Description
String	getListenerId()	Return an optional identifier for the listener.
int	getOrder()	Determine this listener's order in a set of listeners for the same event.
void	onApplicationEvent(ApplicationEvent event)	Handle an application event.
protected void	onApplicationEventInternal(ApplicationEvent event)	Actually process the event, after having filtered according to the desired event source already.
boolean	supportsEventType(org.springframework.core.ResolvableType eventType)	Determine whether this listener actually supports the given event type.
boolean	supportsSourceType(@Nullable Class<?> sourceType)	Determine whether this listener actually supports the given source type.

Methods inherited from class Object

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

Methods inherited from interface ApplicationListener

supportsAsyncExecution

Methods inherited from interface GenericApplicationListener

supportsEventType

Constructor Details

SourceFilteringListener

public SourceFilteringListener(Object source,
 ApplicationListener<?> delegate)

Create a SourceFilteringListener for the given event source.

Parameters:

source - the event source that this listener filters for, only processing events from this source

delegate - the delegate listener to invoke with event from the specified source

SourceFilteringListener

protected SourceFilteringListener(Object source)

Create a SourceFilteringListener for the given event source, expecting subclasses to override the onApplicationEventInternal(ApplicationEvent) method (instead of specifying a delegate listener).

Parameters:

source - the event source that this listener filters for, only processing events from this source

Method Details

onApplicationEvent

public void onApplicationEvent(ApplicationEvent event)

Description copied from interface: ApplicationListener

Handle an application event.

Specified by:

onApplicationEvent in interface ApplicationListener<ApplicationEvent>

Parameters:

event - the event to respond to

supportsEventType

public boolean supportsEventType(org.springframework.core.ResolvableType eventType)

Description copied from interface: GenericApplicationListener

Determine whether this listener actually supports the given event type.

Specified by:

supportsEventType in interface GenericApplicationListener

Parameters:

eventType - the event type (never null)

supportsSourceType

public boolean supportsSourceType(@Nullable Class<?> sourceType)

Description copied from interface: SmartApplicationListener

Determine whether this listener actually supports the given source type.

The default implementation always returns true.

Specified by:

supportsSourceType in interface SmartApplicationListener

Parameters:

sourceType - the source type, or null if no source

getOrder

public int getOrder()

Description copied from interface: SmartApplicationListener

Determine this listener's order in a set of listeners for the same event.

The default implementation returns Ordered.LOWEST_PRECEDENCE.

Specified by:

getOrder in interface org.springframework.core.Ordered

Specified by:

getOrder in interface SmartApplicationListener

getListenerId

public String getListenerId()

Description copied from interface: SmartApplicationListener

Return an optional identifier for the listener.

The default value is an empty String.

Specified by:

getListenerId in interface SmartApplicationListener

See Also:

• EventListener.id()
• ApplicationEventMulticaster.removeApplicationListeners(Predicate)

onApplicationEventInternal

protected void onApplicationEventInternal(ApplicationEvent event)

Actually process the event, after having filtered according to the desired event source already.

The default implementation invokes the specified delegate, if any.

Parameters:

event - the event to process (matching the specified source)