Module it.tidalwave.messagebus

Package it.tidalwave.messagebus

Class MessageBusHelper

java.lang.Object

it.tidalwave.messagebus.MessageBusHelper

public class MessageBusHelper
extends Object

A helper for objects that receive messages by means of listener methods: methods with a single parameter annotated with ListensTo. It finds such methods in the classes of the hierarchy of the owner object that are annotated with SimpleMessageSubscriber, and subscribes or unsubscribes all of them at once. MessageBusHelper doesn't depend on a specific message bus: the actual subscription is performed by means of an MessageBusHelper.Adapter.

Author:

Fabrizio Giudici

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MessageBusHelper.Adapter	An adapter between MessageBusHelper and a specific message bus.
static interface	MessageBusHelper.MethodAdapter<T>	The binding of a listener method to a message bus, which can subscribe and unsubscribe it.

Constructor Summary

Constructors

Constructor	Description
MessageBusHelper()

Method Summary

Modifier and Type	Method	Description
<T> void	publish(Class<T> topicType, T topic)	Publishes a message with an explicit topic.
void	publish(Object message)	Publishes a message.
void	subscribeAll()	Subscribes all the listener methods of the owner object: the methods with a single parameter annotated with ListensTo, declared in the classes of the hierarchy of the owner that are annotated with SimpleMessageSubscriber.
void	unsubscribeAll()	Unsubscribes all the listener methods subscribed by subscribeAll().

Methods inherited from class java.lang.Object

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

Constructor Details

MessageBusHelper

public MessageBusHelper()

Method Details

subscribeAll

public void subscribeAll()

Subscribes all the listener methods of the owner object: the methods with a single parameter annotated with ListensTo, declared in the classes of the hierarchy of the owner that are annotated with SimpleMessageSubscriber. Methods declared in classes that are not annotated are ignored.

unsubscribeAll

public void unsubscribeAll()

Unsubscribes all the listener methods subscribed by subscribeAll().

publish

public void publish(@Nonnull
 Object message)

Publishes a message. The topic is the class of the message.

Parameters:

message - the message to deliver

publish

public <T> void publish(@Nonnull
 Class<T> topicType,
 @Nonnull
 T topic)

Publishes a message with an explicit topic.

Type Parameters:

T - the static type of the topic

Parameters:

topicType - the topic

topic - the message to deliver