org.axonframework.common.annotation
Class MessageHandlerInvoker

java.lang.Object
  org.axonframework.common.annotation.MessageHandlerInvoker

public final class MessageHandlerInvoker
extends Object

Abstract class to support implementations that need to invoke methods based on an annotation.

Since:

0.6

Author:

Allard Buijze

Constructor Summary

MessageHandlerInvoker(Object target, Class<? extends Annotation> annotationType, boolean allowDuplicates)
Initialize a handler invoker for the given target object that has handler method annotated with given annotationType.

Method Summary

MethodMessageHandler	findHandlerMethod(Message message) Finds the handler method that can handle the given message, or null if no such handler exists.
Class	getTargetType() Returns the targetType on which handler methods are invoked.
Object	invokeHandlerMethod(Message parameter) Invoke the handler demarcated with the given annotationClass on the target for the given event.

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageHandlerInvoker

public MessageHandlerInvoker(Object target,
                             Class<? extends Annotation> annotationType,
                             boolean allowDuplicates)

Initialize a handler invoker for the given target object that has handler method annotated with given annotationType.

Parameters:

target - The target to invoke methods on

annotationType - The type of annotation used to demarcate the handler methods

allowDuplicates - Whether or not to accept multiple handlers listening to messages with the same payload type

Method Detail

invokeHandlerMethod

public Object invokeHandlerMethod(Message parameter)
                           throws InvocationTargetException,
                                  IllegalAccessException

Invoke the handler demarcated with the given annotationClass on the target for the given event. Returns the result of the execution of the handler method, or null if no suitable handler was found.

Parameters:

parameter - the event to handle

Returns:

the return value of the invocation

Throws:

IllegalAccessException - when the security manager does not allow the invocation

InvocationTargetException - when the handler throws a checked Exception

findHandlerMethod

public MethodMessageHandler findHandlerMethod(Message message)

Finds the handler method that can handle the given message, or null if no such handler exists.

Parameters:

message - The message to find a handler for

Returns:

The handler for the given message, or null if none exists

getTargetType

public Class getTargetType()

Returns the targetType on which handler methods are invoked. This is the runtime type of the object that contains the method that handles the messages (not per se the Class that declares the method).

Returns:

the targetType on which handler methods are invoked