Package org.refcodes.eventbus

The GenericEventBus is the (virtual) machine wide manager for event handling. It implements a publish/subscribe mechanism.

"... lately some colleagues and me were reasoning on how to do client-side (Browser, JavaScript) communication between web-page components ... decoupled ... in general I recommend taking a look at an event-bus (aka page-bus), with Java why not take a look at the refcodes-eventbus? ... the following “equation” came to mind … simply speaking, the equation Observer pattern + Publish–subscribe pattern = Message broker solves to refcodes-eventbus ..."

Lightweight message broker = event-bus?

A lightweight Message broker can be a good solution for requirements doing in-JVM (Java Virtual Machine) communication as of:

Signaling events to some event-listener … Subscribing your event-listener for some specific events … Publishing events merely to interested event-listeners … Strongly decoupling the publisher and the subscriber … Considering privacy issues (no simple broadcast) …

In the article refcodes-eventbus: Observer + Publish–subscribe = Message broker I describe the refcodes-eventbus accompanied with a plain simple example on how to use it.

The refcodes-eventbus artifact makes use of the refcodes-matcher framework for defining the criteria on when to deliver an event to an event-listener. It also sets on top of the refcodes-observer framework regarding issues around the Observer pattern ... See also "http://www.refcodes.org/blog/publish_subscribe_observe_event-bus"

Interface Summary

Interface	Description
BusEvent	Intuitive Meta-Interface for the BusEvent as used by the EventBus.
BusEvent.BusEventBuilder	Intuitive Meta-Interface for the BusEvent.BusEventBuilder as used by the EventBus.
BusMatcher	A convenience definition of an EventMatcher for the ready to use out of the box EventBusImpl implementation of the generic GenericEventBus definition.
BusObserver	A convenience definition of an Observer for the ready to use out of the box EventBusImpl implementation of the generic GenericEventBus definition.
DispatchStrategyAccessor	Provides an accessor for a DispatchStrategy property.
DispatchStrategyAccessor.DispatchStrategyMutator	Provides a mutator for a DispatchStrategy property.
DispatchStrategyAccessor.DispatchStrategyProperty	Provides a DispatchStrategy property.
EventBus	The EventBus defines a predefined GenericEventBus tailored to use the ActionMetaDataEvent as event type to use.
GenericBusEvent<A,META extends org.refcodes.observer.EventMetaData,SRC extends GenericEventBus<?,?,?,?,?>>	Intuitive Meta-Interface for the GenericActionMetaDataEvent as used by the EventBus.
GenericBusEvent.GenericBusEventBuilder<A,META extends org.refcodes.observer.EventMetaData,SRC extends GenericEventBus<?,?,?,?,?>,B extends GenericBusEvent.GenericBusEventBuilder<A,META,SRC,B>>	Intuitive Meta-Interface for the GenericBusEvent.GenericBusEventBuilder as used by the GenericEventBus.
GenericBusObservable<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,MATCH extends org.refcodes.observer.EventMatcher<E>,H>	The Observable part of the GenericEventBus provides means to register Observer instances.
GenericBusPublisher<E extends org.refcodes.observer.GenericEvent<?>>	The Interface BusPublisher.
GenericEventBus<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,MATCH extends org.refcodes.observer.EventMatcher<E>,META extends org.refcodes.observer.EventMetaData,H>	The GenericEventBus is the (virtual) machine wide manager for GenericActionEvent handling.

Class Summary

Class	Description
AbstractEventBus<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,MATCH extends org.refcodes.observer.EventMatcher<E>,META extends org.refcodes.observer.EventMetaData,H>	The Class AbstractEventBus.
BusEventBuilderImpl	Intuitive Meta-Class for the ActionMetaDataEventBuilderImpl as used by the EventBus.
BusEventImpl	Intuitive Meta-Class for the ActionMetaDataEventImpl as used by the EventBus.
BusMatcherSugar	Declarative syntactic sugar which may be statically imported in order to allow declarative definitions for the BusMatcher elements.
EventBusImpl	The EventBusImpl is a ready to use implementation of a EventBus using a default DispatchStrategy being DispatchStrategy.CASCADE and extending the AbstractEventBus.

Enum Summary

Enum	Description
DispatchStrategy	The DispatchStrategy defines how child events are published within a parent event publish cycle.