Package org.refcodes.eventbus

The GenericEventBus is the (virtual) machine wide manager for event handling.

See: Description

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.
BusObservable<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,EM extends org.refcodes.observer.EventMatcher<E>,H>	The Observable part of the GenericEventBus provides means to register Observer instances.
BusObserver	A convenience definition of an Observer for the ready to use out of the box EventBusImpl implementation of the generic GenericEventBus definition.
BusPublisher<E extends org.refcodes.observer.GenericEvent<?>>	The Interface BusPublisher.
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,EM extends org.refcodes.observer.EventMetaData,SRC extends GenericEventBus<?,?,?,?>>	Intuitive Meta-Interface for the GenericActionMetaDataEvent as used by the EventBus.
GenericBusEvent.GenericBusEventBuilder<A,EM extends org.refcodes.observer.EventMetaData,SRC extends GenericEventBus<?,?,?,?>,B extends GenericBusEvent.GenericBusEventBuilder<A,EM,SRC,B>>	Intuitive Meta-Interface for the GenericBusEvent.GenericBusEventBuilder as used by the GenericEventBus.
GenericEventBus<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,EM extends org.refcodes.observer.EventMatcher<E>,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>,EM extends org.refcodes.observer.EventMatcher<E>,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.
BusObservableImpl<E extends org.refcodes.observer.GenericEvent<?>,O extends org.refcodes.observer.Observer<E>,EM extends org.refcodes.observer.EventMatcher<E>,H>	This delegate hides any additional functionality away from a caller concerning the the provides implementation.
BusPublisherImpl<E extends org.refcodes.observer.GenericEvent<?>>	This delegate hides any additional functionality away from a caller concerning the the provides implementation.
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.

Package org.refcodes.eventbus Description

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"