DefaultEventBus

A default event bus implementation that synchronously publishes events to registered listeners. Listeners can be registered or unregistered for events as necessary. <p/> An event bus enables a publish/subscribe paradigm within Shiro - components can publish or consume events they find relevant without needing to be tightly coupled to other components. This affords great flexibility within Shiro by promoting loose coupling and high cohesion between components and a much safer pluggable architecture that is more resilient to change over time. <h2>Sending Events</h2> If a component wishes to publish events to other components: <pre> MyEvent myEvent = createMyEvent(); eventBus.publish(myEvent); </pre> The event bus will determine the type of event and then dispatch the event to components that wish to receive events of that type. <h2>Receiving Events</h2> A component can receive events of interest by doing the following. <ol> <li>For each type of event you wish to consume, create a method that accepts a single event argument. The method argument type indicates the type of event to receive.</li> <li>Annotate each of these methods with the {@link hunt.shiro.event.Subscribe Subscribe} annotation.</li> <li>Register the component with the event bus: <pre> eventBus.register(myComponent); </pre> </li> </ol> After registering the component, when when an event of a respective type is published, the component's {@code Subscribe}-annotated method(s) will be invoked as expected.

This design (and its constituent helper components) was largely influenced by Guava's <a href="http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/eventbus/EventBus.html">EventBus</a> concept, although no code was shared/imported (even though Guava is Apache 2.0 licensed and could have been used).

This implementation is thread-safe and may be used concurrently.

@since 1.3

class DefaultEventBus : EventBus {

this();

EventListenerResolver getEventListenerResolver();

void setEventListenerResolver(EventListenerResolver eventListenerResolver);

void publish(Object event);

void register(Object instance);

void unregister(Object instance);

}

Constructors

this this(): Undocumented in source.

Members

Functions

getEventListenerResolver EventListenerResolver getEventListenerResolver(): Undocumented in source. Be warned that the author may not have intended to support it.
publish void publish(Object event): Undocumented in source. Be warned that the author may not have intended to support it.
register void register(Object instance): Undocumented in source. Be warned that the author may not have intended to support it.
setEventListenerResolver void setEventListenerResolver(EventListenerResolver eventListenerResolver): Undocumented in source. Be warned that the author may not have intended to support it.
unregister void unregister(Object instance): Undocumented in source. Be warned that the author may not have intended to support it.

Inherited Members

From EventBus

publish void publish(Object event): Publishes the specified event to an event subsystem that will deliver events to relevant {@link Subscribe}rs.
register void register(Object subscriber): Registers all event handler methods on the specified instance to receive relevant events. The handler methods are determined by the {@code EventBus} implementation, typically by using an {@link hunt.shiro.event.support.EventListenerResolver EventListenerResolver} (e.g. {@link hunt.shiro.event.support.AnnotationEventListenerResolver AnnotationEventListenerResolver}).
unregister void unregister(Object subscriber): Unregisters all previously-registered event handler methods on the specified instance. If the specified object was not previously registered, calling this method has no effect.