Class ApplicationListenerMethodAdapter

java.lang.Object

org.springframework.context.event.ApplicationListenerMethodAdapter

All Implemented Interfaces:

EventListener, ApplicationListener<ApplicationEvent>, GenericApplicationListener, SmartApplicationListener, Ordered

Direct Known Subclasses:

TransactionalApplicationListenerMethodAdapter

public class ApplicationListenerMethodAdapter
extends Object
implements GenericApplicationListener

GenericApplicationListener adapter that delegates the processing of an event to an EventListener annotated method.

Delegates to processEvent(ApplicationEvent) to give subclasses a chance to deviate from the default. Unwraps the content of a PayloadApplicationEvent if necessary to allow a method declaration to define any arbitrary event type. If a condition is defined, it is evaluated prior to invoking the underlying method.

Since:

4.2

Author:

Stephane Nicoll, Juergen Hoeller, Sam Brannen, Sebastien Deleuze, Yanming Zhou

Field Summary

Fields

Modifier and Type	Field	Description
protected final org.apache.commons.logging.Log	logger

Fields inherited from interface Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor	Description
ApplicationListenerMethodAdapter(String beanName, Class<?> targetClass, Method method)	Construct a new ApplicationListenerMethodAdapter.

Method Summary

Modifier and Type	Method	Description
protected @Nullable Object	doInvoke(@Nullable Object... args)	Invoke the event listener method with the given argument values.
protected @Nullable String	getCondition()	Return the condition to use.
protected String	getDefaultListenerId()	Determine the default id for the target listener, to be applied in case of no annotation-specified id value.
protected String	getDetailedErrorMessage(Object bean, @Nullable String message)	Add additional details such as the bean type and method signature to the given error message.
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.
protected Object	getTargetBean()	Return the target bean instance to use.
protected Method	getTargetMethod()	Return the target listener method.
protected void	handleAsyncError(Throwable t)
protected void	handleResult(Object result)
protected boolean	isDefaultExecution()	Return whether default execution is applicable for the target listener.
void	onApplicationEvent(ApplicationEvent event)	Handle an application event.
void	processEvent(ApplicationEvent event)	Process the specified ApplicationEvent, checking if the condition matches and handling a non-null result, if any.
protected @Nullable Object @Nullable []	resolveArguments(ApplicationEvent event)	Resolve the method arguments to use for the specified ApplicationEvent.
boolean	shouldHandle(ApplicationEvent event)	Determine whether the listener method would actually handle the given event, checking if the condition matches.
boolean	supportsEventType(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.
String	toString()

Methods inherited from class Object

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

Methods inherited from interface ApplicationListener

supportsAsyncExecution

Methods inherited from interface GenericApplicationListener

supportsEventType

Field Details

logger

protected final org.apache.commons.logging.Log logger

Constructor Details

ApplicationListenerMethodAdapter

public ApplicationListenerMethodAdapter(String beanName,
 Class<?> targetClass,
 Method method)

Construct a new ApplicationListenerMethodAdapter.

Parameters:

beanName - the name of the bean to invoke the listener method on

targetClass - the target class that the method is declared on

method - the listener method to invoke

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(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 Ordered

Specified by:

getOrder in interface SmartApplicationListener

Returns:

the order value

See Also:

• Ordered.HIGHEST_PRECEDENCE
• Ordered.LOWEST_PRECEDENCE

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)

getDefaultListenerId

protected String getDefaultListenerId()

Determine the default id for the target listener, to be applied in case of no annotation-specified id value.

The default implementation builds a method name with parameter types.

Since:

5.3.5

See Also:

• getListenerId()

isDefaultExecution

protected boolean isDefaultExecution()

Return whether default execution is applicable for the target listener.

Since:

6.2

See Also:

• onApplicationEvent(ApplicationEvent)
• EventListener.defaultExecution()

processEvent

public void processEvent(ApplicationEvent event)

Process the specified ApplicationEvent, checking if the condition matches and handling a non-null result, if any.

Parameters:

event - the event to process through the listener method

shouldHandle

public boolean shouldHandle(ApplicationEvent event)

Determine whether the listener method would actually handle the given event, checking if the condition matches.

Parameters:

event - the event to process through the listener method

Since:

6.1

resolveArguments

protected @Nullable Object @Nullable [] resolveArguments(ApplicationEvent event)

Resolve the method arguments to use for the specified ApplicationEvent.

These arguments will be used to invoke the method handled by this instance. Can return null to indicate that no suitable arguments could be resolved and therefore the method should not be invoked at all for the specified event.

handleResult

protected void handleResult(Object result)

handleAsyncError

protected void handleAsyncError(Throwable t)

doInvoke

protected @Nullable Object doInvoke(@Nullable Object... args)

Invoke the event listener method with the given argument values.

getTargetBean

protected Object getTargetBean()

Return the target bean instance to use.

getTargetMethod

protected Method getTargetMethod()

Return the target listener method.

Since:

5.3

getCondition

protected @Nullable String getCondition()

Return the condition to use.

Matches the condition attribute of the EventListener annotation or any matching attribute on a composed annotation that is meta-annotated with @EventListener.

getDetailedErrorMessage

protected String getDetailedErrorMessage(Object bean,
 @Nullable String message)

Add additional details such as the bean type and method signature to the given error message.

Parameters:

message - error message to append the HandlerMethod details to

toString

public String toString()

Overrides:

toString in class Object