org.springframework.context.event

Class ApplicationListenerMethodAdapter

java.lang.Object

org.springframework.context.event.ApplicationListenerMethodAdapter

All Implemented Interfaces:

java.util.EventListener, ApplicationListener<ApplicationEvent>, GenericApplicationListener, Ordered

Direct Known Subclasses:

ApplicationListenerMethodTransactionalAdapter

public class ApplicationListenerMethodAdapter
extends java.lang.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, Sam Brannen

Field Summary

Fields

Modifier and Type	Field and Description
private ApplicationContext	applicationContext
private java.lang.String	beanName
private java.lang.reflect.Method	bridgedMethod
private java.lang.String	condition
private java.util.List<ResolvableType>	declaredEventTypes
private EventExpressionEvaluator	evaluator
private EventListener	eventListener
protected Log	logger
private java.lang.reflect.Method	method
private AnnotatedElementKey	methodKey
private java.lang.Class<?>	targetClass

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
private void	assertTargetBean(java.lang.reflect.Method method, java.lang.Object targetBean, java.lang.Object[] args) Assert that the target bean class is an instance of the class where the given method is declared.
protected java.lang.Object	doInvoke(java.lang.Object... args) Invoke the event listener method with the given argument values.
protected java.lang.String	getCondition() Return the condition to use.
protected java.lang.String	getDetailedErrorMessage(java.lang.Object bean, java.lang.String message) Add additional details such as the bean type and method signature to the given error message.
protected EventListener	getEventListener()
private java.lang.String	getInvocationErrorMessage(java.lang.Object bean, java.lang.String message, java.lang.Object[] resolvedArgs)
protected <A extends java.lang.annotation.Annotation> A	getMethodAnnotation(java.lang.Class<A> annotationType)
int	getOrder() Get the order value of this object.
private ResolvableType	getResolvableType(ApplicationEvent event)
protected java.lang.Object	getTargetBean() Return the target bean instance to use.
protected void	handleResult(java.lang.Object result)
(package private) void	init(ApplicationContext applicationContext, EventExpressionEvaluator evaluator) Initialize this instance.
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.
private void	publishEvent(java.lang.Object event)
protected java.lang.Object[]	resolveArguments(ApplicationEvent event) Resolve the method arguments to use for the specified ApplicationEvent.
private java.util.List<ResolvableType>	resolveDeclaredEventTypes()
private boolean	shouldHandle(ApplicationEvent event, java.lang.Object[] args)
boolean	supportsEventType(ResolvableType eventType) Determine whether this listener actually supports the given event type.
boolean	supportsSourceType(java.lang.Class<?> sourceType) Determine whether this listener actually supports the given source type.
java.lang.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

beanName

private final java.lang.String beanName

method

private final java.lang.reflect.Method method

targetClass

private final java.lang.Class<?> targetClass

bridgedMethod

private final java.lang.reflect.Method bridgedMethod

declaredEventTypes

private final java.util.List<ResolvableType> declaredEventTypes

methodKey

private final AnnotatedElementKey methodKey

applicationContext

private ApplicationContext applicationContext

evaluator

private EventExpressionEvaluator evaluator

condition

private java.lang.String condition

eventListener

private EventListener eventListener

Constructor Detail

ApplicationListenerMethodAdapter

public ApplicationListenerMethodAdapter(java.lang.String beanName,
                                        java.lang.Class<?> targetClass,
                                        java.lang.reflect.Method method)

Method Detail

init

void init(ApplicationContext applicationContext,
          EventExpressionEvaluator evaluator)

Initialize this instance.

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

supportsSourceType

public boolean supportsSourceType(java.lang.Class<?> sourceType)

Description copied from interface: GenericApplicationListener

Determine whether this listener actually supports the given source type.

Specified by:

supportsSourceType in interface GenericApplicationListener

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

protected java.lang.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(java.lang.Object result)

publishEvent

private void publishEvent(java.lang.Object event)

shouldHandle

private boolean shouldHandle(ApplicationEvent event,
                             java.lang.Object[] args)

getMethodAnnotation

protected <A extends java.lang.annotation.Annotation> A getMethodAnnotation(java.lang.Class<A> annotationType)

doInvoke

protected java.lang.Object doInvoke(java.lang.Object... args)

Invoke the event listener method with the given argument values.

getTargetBean

protected java.lang.Object getTargetBean()

Return the target bean instance to use.

getEventListener

protected EventListener getEventListener()

getCondition

protected java.lang.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 java.lang.String getDetailedErrorMessage(java.lang.Object bean,
                                                   java.lang.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

assertTargetBean

private void assertTargetBean(java.lang.reflect.Method method,
                              java.lang.Object targetBean,
                              java.lang.Object[] args)

Assert that the target bean class is an instance of the class where the given method is declared. In some cases the actual bean instance at event- processing time may be a JDK dynamic proxy (lazy initialization, prototype beans, and others). Event listener beans that require proxying should prefer class-based proxy mechanisms.

getInvocationErrorMessage

private java.lang.String getInvocationErrorMessage(java.lang.Object bean,
                                                   java.lang.String message,
                                                   java.lang.Object[] resolvedArgs)

getResolvableType

private ResolvableType getResolvableType(ApplicationEvent event)

resolveDeclaredEventTypes

private java.util.List<ResolvableType> resolveDeclaredEventTypes()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object