org.axonframework.messaging.annotation

Class WrappedMessageHandlingMember<T>

java.lang.Object

org.axonframework.messaging.annotation.WrappedMessageHandlingMember<T>

Type Parameters:

T - the entity type

All Implemented Interfaces:

MessageHandlingMember<T>

Direct Known Subclasses:

SagaMethodMessageHandlingMember

public abstract class WrappedMessageHandlingMember<T>
extends Object
implements MessageHandlingMember<T>

Abstract implementation of a MessageHandlingMember that delegates to a wrapped MessageHandlingMember. Extend this class to provide additional functionality to the delegate member.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	WrappedMessageHandlingMember(MessageHandlingMember<T> delegate) Initializes the member using the given delegate.

Method Summary

Modifier and Type	Method and Description
Optional<Map<String,Object>>	annotationAttributes(Class<? extends Annotation> annotationType) Get the attributes of an annotation of given annotationType on the method of the target entity.
boolean	canHandle(Message<?> message) Checks if this handler is capable of handling the given message.
Object	handle(Message<?> message, T target) Handles the given message by invoking the appropriate method on given target.
boolean	hasAnnotation(Class<? extends Annotation> annotationType) Checks whether the method of the target entity contains the given annotationType.
Class<?>	payloadType() Returns the payload type of messages that can be processed by this handler.
int	priority() Returns a number representing the priority of this handler over other handlers capable of processing the same message.
<HT> Optional<HT>	unwrap(Class<HT> handlerType) Returns the wrapped handler object if its type is an instance of the given handlerType.

Methods inherited from class java.lang.Object

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

Constructor Detail

WrappedMessageHandlingMember

protected WrappedMessageHandlingMember(MessageHandlingMember<T> delegate)

Initializes the member using the given delegate.

Parameters:

delegate - the actual message handling member to delegate to

Method Detail

payloadType

public Class<?> payloadType()

Description copied from interface: MessageHandlingMember

Returns the payload type of messages that can be processed by this handler.

Specified by:

payloadType in interface MessageHandlingMember<T>

Returns:

The payload type of messages expected by this handler

priority

public int priority()

Description copied from interface: MessageHandlingMember

Returns a number representing the priority of this handler over other handlers capable of processing the same message.

In general, a handler with a higher priority will receive the message before (or instead of) handlers with a lower priority. However, the priority value may not be the only indicator that is used to determine the order of invocation. For instance, a message processor may decide to ignore the priority value if one message handler is a more specific handler of the message than another handler.

Specified by:

priority in interface MessageHandlingMember<T>

Returns:

Number indicating the priority of this handler over other handlers

canHandle

public boolean canHandle(Message<?> message)

Description copied from interface: MessageHandlingMember

Checks if this handler is capable of handling the given message.

Specified by:

canHandle in interface MessageHandlingMember<T>

Parameters:

message - The message that is to be handled

Returns:

true if the handler is capable of handling the message, false otherwise

handle

public Object handle(Message<?> message,
                     T target)
              throws Exception

Description copied from interface: MessageHandlingMember

Handles the given message by invoking the appropriate method on given target. This may result in an exception if the given target is not capable of handling the message or if an exception is thrown during invocation of the method.

Specified by:

handle in interface MessageHandlingMember<T>

Parameters:

message - The message to handle

target - The target to handle the message

Returns:

The message handling result in case the invocation was successful

Throws:

Exception - when there was a problem that prevented invocation of the method or if an exception was thrown from the invoked method

unwrap

public <HT> Optional<HT> unwrap(Class<HT> handlerType)

Description copied from interface: MessageHandlingMember

Returns the wrapped handler object if its type is an instance of the given handlerType. For instance, if this method is invoked with Executable and the message is handled by a method of the target entity, then this method will return the method handle as a Method.

Specified by:

unwrap in interface MessageHandlingMember<T>

Type Parameters:

HT - The wrapped handler type

Parameters:

handlerType - The expected type of the wrapped handler

Returns:

An Optional containing the wrapped handler object or an empty Optional if the handler is not an instance of the given handlerType

annotationAttributes

public Optional<Map<String,Object>> annotationAttributes(Class<? extends Annotation> annotationType)

Description copied from interface: MessageHandlingMember

Get the attributes of an annotation of given annotationType on the method of the target entity. If the annotation is present on the target method an Optional is returned containing the properties mapped by their name. If the annotation is not present an empty Optional is returned.

Specified by:

annotationAttributes in interface MessageHandlingMember<T>

Parameters:

annotationType - The annotation to check for on the target method

Returns:

An optional containing a map of the properties of the annotation, or an empty optional if the annotation is missing on the method

hasAnnotation

public boolean hasAnnotation(Class<? extends Annotation> annotationType)

Description copied from interface: MessageHandlingMember

Checks whether the method of the target entity contains the given annotationType.

Specified by:

hasAnnotation in interface MessageHandlingMember<T>

Parameters:

annotationType - Annotation to check for on the target method

Returns:

true if the annotation is present on the target method, false otherwise