org.springframework.context.event

Class ApplicationListenerMethodAdapter

java.lang.Object

org.springframework.context.event.ApplicationListenerMethodAdapter

All Implemented Interfaces:

EventListener, ApplicationListener<ApplicationEvent>, GenericApplicationListener, Ordered

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 sub-classes a chance to deviate from the default. Unwraps the content of a PayloadApplicationEvent if necessary to allow 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

Field Summary

Fields

Modifier and Type	Field and Description
protected Log	logger

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
ApplicationListenerMethodAdapter(String beanName, Class<?> targetClass, Method method)

Method Summary

Modifier and Type	Method and Description
protected Object	doInvoke(Object... args) Invoke the event listener method with the given argument values.
protected String	getCondition() Return the condition to use.
protected String	getDetailedErrorMessage(Object bean, String message) Add additional details such as the bean type and method signature to the given error message.
int	getOrder() Get the order value of this object.
protected Object	getTargetBean() Return the target bean instance to use.
protected void	handleResult(Object result)
void	onApplicationEvent(ApplicationEvent event) Handle an application event.
void	processEvent(ApplicationEvent event) Process the specified ApplicationEvent, checking if the condition match and handling non-null result, if any.
protected Object[]	resolveArguments(ApplicationEvent event) Resolve the method arguments to use for the specified ApplicationEvent.
boolean	supportsEventType(ResolvableType eventType) Determine whether this listener actually supports the given event type.
boolean	supportsSourceType(Class<?> sourceType) Determine whether this listener actually supports the given source type.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final Log logger

Constructor Detail

ApplicationListenerMethodAdapter

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

Method Detail

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: GenericApplicationListener

Determine whether this listener actually supports the given source type.

Specified by:

supportsSourceType in interface GenericApplicationListener

Parameters:

sourceType - the source type, or null if no source

getOrder

public int getOrder()

Description copied from interface: Ordered

Get the order value of this object.

Higher values are interpreted as lower priority. As a consequence, the object with the lowest value has the highest priority (somewhat analogous to Servlet load-on-startup values).

Same order values will result in arbitrary sort positions for the affected objects.

Specified by:

getOrder in interface Ordered

Returns:

the order value

See Also:

Ordered.HIGHEST_PRECEDENCE, Ordered.LOWEST_PRECEDENCE

processEvent

public void processEvent(ApplicationEvent event)

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

resolveArguments

@Nullable
protected Object[] 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)

doInvoke

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

Invoke the event listener method with the given argument values.

getTargetBean

protected Object getTargetBean()

Return the target bean instance to use.

getCondition

@Nullable
protected 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,
                                         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