org.bushe.swing.event
Interface EventService

All Known Implementing Classes:
SwingEventService, ThreadSafeEventService

public interface EventService

The core interface. An EventService provides publish/subscribe services to a single JVM using Class-based and String-based (i.e. "topic") publications and subscriptions.

In class-based pub/sub, EventSubscribers subscribe to a type on an EventService, such as the EventBus, by providing a class, interface or generic type. The EventService notifies subscribers when objects are published on the EventService with a matching type. Full class semantics are respected. That is, if a subscriber subscribes to a class, the subscriber is notified if an object of that class is publish or if an object of a subclass of that class is published. Likewise if a subscriber subscribes to an interface, it will be notified if any object that implements that interface is published. Subscribers can subscribe "exactly" using subscribeExactly(Class, EventSubscriber) so that they are notified only if an object of the exact class is published (and will not be notified if subclasses are published, since this would not be "exact")

In topic-based pub/sub, an object "payload" is published on a topic name (String). EventTopicSubscribers subscribe to either the exact name of the topic or they may subscribe using a Regular Expression that is used to match topic names.

See the overview for an general introduction and package documentation for usage details and examples.

A single subscriber cannot subscribe more than once to an event or topic name. EventService implementations should handle double-subscription requests by returning false on subscribe(). A single EventSubscriber can subscribe to more than one event class, and a single EventTopicSubscriber can subscribe to more than one topic name or pattern. A single object may implement both EventSubscriber and EventTopicSubscriber interfaces. Subscribers are guaranteed to only be called for the classes and/or topic names they subscribe to. If a subscriber subscribes to a topic and to a regular expression that matches the topic name, this is considered two different subscriptions and the subscriber will be called twice for the publication on the topic. Similarly, if a subscriber subscribes to a class and its subclasses using subscribe() and again to a class of the same type using subscribeExactly(), this is considered two different subscriptions and the subscriber will be called twice for the publication for a single event of the exact type.

By default the EventService only holds WeakReferences to subscribers. If a subscriber has no references to it, then it can be garbage collected. This avoids memory leaks in exchange for the risk of accidentally adding a listener and have it disappear unexpectedly. If you want to subscribe a subscriber that will have no other reference to it, then use one of the subscribeStrongly() methods, which will prevent garbage collection.

Unless garbage collected, EventSubscribers will remain subscribed until they are passed to one of the unsubscribe() methods with the event class or topic name to which there are subscribed.

Subscribers are called in the order in which they are subscribed by default (FIFO), unless subscribers implement Prioritized. Those subscribers that implement Prioritized and return a negative priority are moved to the front of the list (the more negative, the more to the front). Those subscribers that implement Prioritized and return a positive priority are moved to the end of the list (the more positive, the more to the back). The FIFO guarantee is only valid for the same subscribe() call. That is, the order of two subscribers, one to List.class and the other to ArrayList.class is not guaranteed to be in the order of subscription when an ArrayList is published. The same is true for topic subscribers when using RegEx expressions - when "Foo" is published, the order of subscribers that are subscribed to "Foo", "Fo*" and "F*" are not guaranteed, though the second "Fo*" subscriber will never be called before the first "Fo*" subscriber (ditto List and ArrayList). Prioritized subscribers are always guaranteed to be in the order of priority, no matter the call or the resulting mix of subscribers. All ordering rules apply to all types subscribers: class, topic, pattern, veto, etc. For Swing users, note that FIFO is the opposite of Swing, where event listeners are called in the reverse order of when they were subscribed (FILO).

Publication on a class or topic name can be vetoed by a VetoEventListener. All VetoEventListeners are checked before any EventSubscribers or EventTopicSubscribers are called. This is unlike the JavaBean's VetoPropertyEventListener which can leave side effects and half-propogated events. VetoEventListeners are subscribed in the same manner as EventSubscribers and EventTopicSubscribers.

The state of a published event can be tracked if an event or a topic's payload object implements the PublicationStatus interface. EventServices are required to set such objects' PublicationStatus at the appropriate times during publication.

This simple example prints "Hello World"

 EventService eventService = new ThreadSafeEventService();
 //Create a subscriber
 EventTopicSubscriber subscriber = new EventTopicSubscriber() {
    public void onEvent(String topic, Object event) {
        System.out.println(topic+" "+event);
    }
 });
 eventService.subscribe("Hello", subscriber);
 eventService.publish("Hello", "World");
 System.out.println(subscriber + " Since the reference is used after it is subscribed, it doesn't get garbage collected, this is not necessary if you use subscribeStrongly()");
 

Events and/or topic data can be cached, but are not by default. To cache events or topic data, call setDefaultCacheSizePerClassOrTopic(int), setCacheSizeForEventClass(Class, int), or setCacheSizeForTopic(String, int), setCacheSizeForTopic(Pattern, int). Retrieve cached values with getLastEvent(Class), getLastTopicData(String), getCachedEvents(Class), or getCachedTopicData(String). Using caching while subscribing is most likely to make sense only if you subscribe and publish on the same thread (so caching is very useful for Swing applications since both happen on the EDT in a single-threaded manner). In multithreaded applications, you never know if your subscriber has handled an event while it was being subscribed (before the subscribe() method returned) that is newer or older than the retrieved cached value (taken before or after subscribe() respectively).

There is nothing special about the term "Event," this could just as easily be called a "Message" Service, this term is already taken by the JMS, which is similar, but is used across processes and networks.

See Also:
ThreadSafeEventService} for the default implementation, SwingEventService} for the Swing-safe implementation, EventBus} for simple access to the Swing-safe implementation, org.bushe.swing.event.annotation.EventSubscriber} for subscription annotations, org.bushe.swing.event.annotation.EventTopicSubscriber} for subscription annotations

Method Summary
 void clearAllSubscribers()
          Clears all current subscribers and veto subscribers
 void clearCache()
          Clear all event caches for all topics and event.
 void clearCache(Class eventClass)
          Clears the event cache for a specific event class or interface and it's any of it's subclasses or implementing classes.
 void clearCache(Pattern pattern)
          Clears the topic data cache for all topics that match a particular pattern.
 void clearCache(String topic)
          Clears the topic data cache for a specific topic name.
<T> List<T>
getCachedEvents(Class<T> eventClass)
          When caching, returns the last set of event published for the type supplied.
 List getCachedTopicData(String topic)
          When caching, returns the last set of payload objects published on the topic name supplied.
 int getCacheSizeForEventClass(Class eventClass)
          Returns the number of events cached for a particular class of event.
 int getCacheSizeForTopic(String topic)
          Returns the number of cached data objects published on a particular topic.
 int getDefaultCacheSizePerClassOrTopic()
          The default number of events or payloads kept per event class or topic
<T> T
getLastEvent(Class<T> eventClass)
          When caching, returns the last event publish for the type supplied.
 Object getLastTopicData(String topic)
          When caching, returns the last payload published on the topic name supplied.
<T> List<T>
getSubscribers(Class<T> eventClass)
          Union of getSubscribersToClass(Class) and getSubscribersToExactClass(Class)
<T> List<T>
getSubscribers(Pattern pattern)
          Gets the subscribers that subscribed to a regular expression.
<T> List<T>
getSubscribers(String topic)
          Union of getSubscribersByPattern(String) and geSubscribersToTopic(String)
<T> List<T>
getSubscribers(Type type)
          Gets the subscribers that subscribed to a generic type.
<T> List<T>
getSubscribersByPattern(String topic)
          Gets the subscribers that subscribed with a Pattern that matches the given topic.
<T> List<T>
getSubscribersToClass(Class<T> eventClass)
          Gets subscribers that subscribed with the given a class, but not those subscribed exactly to the class.
<T> List<T>
getSubscribersToExactClass(Class<T> eventClass)
          Gets subscribers that are subscribed exactly to a class, but not those subscribed non-exactly to a class.
<T> List<T>
getSubscribersToTopic(String topic)
          Get the subscribers that subscribed to a topic.
<T> List<T>
getVetoEventListeners(String topicOrPattern)
          Union of getVetoSubscribersToTopic(String) and getVetoSubscribersByPattern(String) Misnamed method, should be called getVetoSubscribers(String).
<T> List<T>
getVetoSubscribers(Class<T> eventClass)
          Gets veto subscribers that subscribed to a given class.
<T> List<T>
getVetoSubscribers(Pattern pattern)
          Gets the veto subscribers that subscribed to a regular expression.
<T> List<T>
getVetoSubscribers(String topic)
          Deprecated. use getVetoSubscribersToTopic instead for direct replacement, or use getVetoEventListeners to get topic and pattern matchers. In EventBus 2.0 this name will replace getVetoEventListeners() and have it's union functionality
<T> List<T>
getVetoSubscribersByPattern(String topic)
          Gets the veto subscribers that are subscribed by pattern that match the topic.
<T> List<T>
getVetoSubscribersToClass(Class<T> eventClass)
          Gets the veto subscribers that subscribed to a class.
<T> List<T>
getVetoSubscribersToExactClass(Class<T> eventClass)
          Get veto subscribers that subscribed to a given class exactly.
<T> List<T>
getVetoSubscribersToTopic(String topic)
          Gets the veto subscribers that subscribed to a topic.
 void publish(Object event)
          Publishes an object so that subscribers will be notified if they subscribed to the object's class, one of its subclasses, or to one of the interfaces it implements.
 void publish(String topic, Object o)
          Publishes an object on a topic name so that all subscribers to that name or a Regular Expression that matches the topic name will be notified.
 void publish(Type genericType, Object event)
          Use this method to publish generified objects to subscribers of Types, i.e.
 void setCacheSizeForEventClass(Class eventClass, int cacheSize)
          Set the number of events cached for a particular class of event.
 void setCacheSizeForTopic(Pattern pattern, int cacheSize)
          Set the number of published data objects cached for a topics matching a pattern.
 void setCacheSizeForTopic(String topicName, int cacheSize)
          Set the number of published data objects cached for a particular event topic.
 void setDefaultCacheSizePerClassOrTopic(int defaultCacheSizePerClassOrTopic)
          Sets the default cache size for each kind of event, default is 0 (no caching).
 boolean subscribe(Class eventClass, EventSubscriber subscriber)
          Subscribes an EventSubscriber to the publication of objects matching a type.
 boolean subscribe(Pattern topicPattern, EventTopicSubscriber subscriber)
          Subscribes an EventSubscriber to the publication of all the topic names that match a RegEx Pattern.
 boolean subscribe(String topic, EventTopicSubscriber subscriber)
          Subscribes an EventTopicSubscriber to the publication of a topic name.
 boolean subscribe(Type type, EventSubscriber subscriber)
          Subscribe an EventSubscriber to publication of generic Types.
 boolean subscribeExactly(Class eventClass, EventSubscriber subscriber)
          Subscribes an EventSubscriber to the publication of objects exactly matching a type.
 boolean subscribeExactlyStrongly(Class eventClass, EventSubscriber subscriber)
          Subscribes an EventSubscriber to the publication of objects matching a type exactly.
 boolean subscribeStrongly(Class eventClass, EventSubscriber subscriber)
          Subscribes an EventSubscriber to the publication of objects matching a type.
 boolean subscribeStrongly(Pattern topicPattern, EventTopicSubscriber subscriber)
          Subscribes a subscriber to all the event topic names that match a RegEx expression.
 boolean subscribeStrongly(String topic, EventTopicSubscriber subscriber)
          Subscribes a subscriber to an event topic name.
 boolean subscribeVetoListener(Class eventClass, VetoEventListener vetoListener)
          Subscribes a VetoEventListener to publication of event matching a class.
 boolean subscribeVetoListener(Pattern topicPattern, VetoTopicEventListener vetoListener)
          Subscribes an VetoTopicEventListener to all the topic names that match the RegEx Pattern.
 boolean subscribeVetoListener(String topic, VetoTopicEventListener vetoListener)
          Subscribes a VetoTopicEventListener to a topic name.
 boolean subscribeVetoListenerExactly(Class eventClass, VetoEventListener vetoListener)
          Subscribes a VetoEventListener to publication of an exact event class.
 boolean subscribeVetoListenerExactlyStrongly(Class eventClass, VetoEventListener vetoListener)
          Subscribes a VetoEventListener for an event class (but not its subclasses).
 boolean subscribeVetoListenerStrongly(Class eventClass, VetoEventListener vetoListener)
          Subscribes a VetoEventListener for an event class and its subclasses.
 boolean subscribeVetoListenerStrongly(Pattern topicPattern, VetoTopicEventListener vetoListener)
          Subscribes a VetoTopicEventListener to a set of topics that match a RegEx expression.
 boolean subscribeVetoListenerStrongly(String topic, VetoTopicEventListener vetoListener)
          Subscribes a VetoEventListener to a topic name.
 boolean unsubscribe(Class eventClass, EventSubscriber subscriber)
          Stop the subscription for a subscriber that is subscribed to a class.
 boolean unsubscribe(Class eventClass, Object subscribedByProxy)
          Stop a subscription for an object that is subscribed with a ProxySubscriber.
 boolean unsubscribe(Pattern topicPattern, EventTopicSubscriber subscriber)
          Stop the subscription for a subscriber that is subscribed to event topics via a Pattern.
 boolean unsubscribe(Pattern pattern, Object subscribedByProxy)
          When using annotations, an object may be subscribed by proxy.
 boolean unsubscribe(String topic, EventTopicSubscriber subscriber)
          Stop the subscription for a subscriber that is subscribed to an event topic.
 boolean unsubscribe(String topic, Object subscribedByProxy)
          Stop a subscription for an object that is subscribed to a topic with a ProxySubscriber.
 boolean unsubscribeExactly(Class eventClass, EventSubscriber subscriber)
          Stop the subscription for a subscriber that is subscribed to an exact class.
 boolean unsubscribeExactly(Class eventClass, Object subscribedByProxy)
          Stop a subscription for an object that is subscribed exactly with a ProxySubscriber.
 boolean unsubscribeVeto(Class eventClass, Object subscribedByProxy)
          Stop a veto subscription for an object that is subscribed with a ProxySubscriber.
 boolean unsubscribeVeto(Pattern pattern, Object subscribedByProxy)
          When using annotations, an object may be subscribed by proxy.
 boolean unsubscribeVeto(String topic, Object subscribedByProxy)
          Stop a veto subscription for an object that is subscribed to a topic with a ProxySubscriber.
 boolean unsubscribeVetoExactly(Class eventClass, Object subscribedByProxy)
          Stop a veto subscription for an object that is subscribed exactly with a ProxySubscriber.
 boolean unsubscribeVetoListener(Class eventClass, VetoEventListener vetoListener)
          Stop the subscription for a vetoListener that is subscribed to an event class and its subclasses.
 boolean unsubscribeVetoListener(Pattern topicPattern, VetoTopicEventListener vetoListener)
          Stop the subscription for a VetoTopicEventListener that is subscribed to an event topic RegEx pattern.
 boolean unsubscribeVetoListener(String topic, VetoTopicEventListener vetoListener)
          Stop the subscription for a VetoTopicEventListener that is subscribed to an event topic name.
 boolean unsubscribeVetoListenerExactly(Class eventClass, VetoEventListener vetoListener)
          Stop the subscription for a vetoListener that is subscribed to an event class (but not its subclasses).
 

Method Detail

publish

void publish(Object event)
Publishes an object so that subscribers will be notified if they subscribed to the object's class, one of its subclasses, or to one of the interfaces it implements.

Parameters:
event - the object to publish

publish

void publish(Type genericType,
             Object event)
Use this method to publish generified objects to subscribers of Types, i.e. subscribers that use subscribe(Type, EventSubscriber), and to publish to subscribers of the non-generic type.

Due to generic type erasure, the type must be supplied by the caller. You can get a declared object's type by using the TypeReference class. For Example:

 TypeReference<List<Trade>> subscribingTypeReference = new TypeReference<List<Trade>>(){};
 EventBus.subscribe(subscribingTypeReference.getType(), mySubscriber);
 EventBus.subscribe(List.class, thisSubscriberWillGetCalledToo);
 ...
 //Likely in some other class
 TypeReference<List<Trade>> publishingTypeReference = new TypeReference<List<Trade>>(){};
 List<Trade> trades = new ArrayList<Trade>();
 EventBus.publish(publishingTypeReference.getType(), trades);
 trades.add(trade);
 EventBus.publish(publishingTypeReference.getType(), trades);
 

Parameters:
genericType - the generified type of the published object.
event - The event that occurred

publish

void publish(String topic,
             Object o)
Publishes an object on a topic name so that all subscribers to that name or a Regular Expression that matches the topic name will be notified.

Parameters:
topic - The name of the topic subscribed to
o - the object to publish

subscribe

boolean subscribe(Class eventClass,
                  EventSubscriber subscriber)
Subscribes an EventSubscriber to the publication of objects matching a type. Only a WeakReference to the subscriber is held by the EventService.

Subscribing to a class means the subscriber will be called when objects of that class are published, when objects of subclasses of the class are published, when objects implementing any of the interfaces of the class are published, or when generic types are published with the class' raw type.

Subscription is weak by default to avoid having to call unsubscribe(), and to avoid the memory leaks that would occur if unsubscribe was not called. The service will respect the WeakReference semantics. In other words, if the subscriber has not been garbage collected, then onEvent(Object) will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same EventSubscriber hard reference to stop a subscription immediately.

The service will create the WeakReference on behalf of the caller.

Parameters:
eventClass - the class of published objects to subscriber listen to
subscriber - The subscriber that will accept the events of the event class when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribe

boolean subscribe(Type type,
                  EventSubscriber subscriber)
Subscribe an EventSubscriber to publication of generic Types. Subscribers will only be notified for publications using publish(java.lang.reflect.Type, Object).

Due to generic type erasure, the type must be supplied by the publisher. You can get a declared object's type by using the TypeReference class. For Example:

 TypeReference<List<Trade>> subscribingTypeReference = new TypeReference<List<Trade>>(){};
 EventBus.subscribe(subscribingTypeReference.getType(), mySubscriber);
 EventBus.subscribe(List.class, thisSubscriberWillGetCalledToo);
 ...
 //Likely in some other class
 TypeReference<List<Trade>> publishingTypeReference = new TypeReference<List<Trade>>(){};
 List<Trade> trades = new ArrayList<Trade>();
 EventBus.publish(publishingTypeReference.getType(), trades);
 trades.add(trade);
 EventBus.publish(publishingTypeReference.getType(), trades);
 

Parameters:
type - the generic type to subscribe to
subscriber - the subscriber to the type
Returns:
true if a new subscription is made, false if it already existed

subscribeExactly

boolean subscribeExactly(Class eventClass,
                         EventSubscriber subscriber)
Subscribes an EventSubscriber to the publication of objects exactly matching a type. Only a WeakReference to the subscriber is held by the EventService.

Subscription is weak by default to avoid having to call unsubscribe(), and to avoid the memory leaks that would occur if unsubscribe was not called. The service will respect the WeakReference semantics. In other words, if the subscriber has not been garbage collected, then the onEvent will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same EventSubscriber hard reference to stop a subscription immediately.

The service will create the WeakReference on behalf of the caller.

Parameters:
eventClass - the class of published objects to listen to
subscriber - The subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribe

boolean subscribe(String topic,
                  EventTopicSubscriber subscriber)
Subscribes an EventTopicSubscriber to the publication of a topic name. Only a WeakReference to the subscriber is held by the EventService.

Subscription is weak by default to avoid having to call unsubscribe(), and to avoid the memory leaks that would occur if unsubscribe was not called. The service will respect the WeakReference semantics. In other words, if the subscriber has not been garbage collected, then the onEvent will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same EventSubscriber hard reference to stop a subscription immediately.

Parameters:
topic - the name of the topic listened to
subscriber - The topic subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribe

boolean subscribe(Pattern topicPattern,
                  EventTopicSubscriber subscriber)
Subscribes an EventSubscriber to the publication of all the topic names that match a RegEx Pattern. Only a WeakReference to the subscriber is held by the EventService.

Subscription is weak by default to avoid having to call unsubscribe(), and to avoid the memory leaks that would occur if unsubscribe was not called. The service will respect the WeakReference semantics. In other words, if the subscriber has not been garbage collected, then the onEvent will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same EventSubscriber hard reference to stop a subscription immediately.

Parameters:
topicPattern - pattern that matches to the name of the topic published to
subscriber - The topic subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribeStrongly

boolean subscribeStrongly(Class eventClass,
                          EventSubscriber subscriber)
Subscribes an EventSubscriber to the publication of objects matching a type.

The semantics are the same as subscribe(Class, EventSubscriber), except that the EventService holds a regularly reference, not a WeakReference.

The subscriber will remain subscribed until unsubscribe(Class,EventSubscriber) is called.

Parameters:
eventClass - the class of published objects to listen to
subscriber - The subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribeExactlyStrongly

boolean subscribeExactlyStrongly(Class eventClass,
                                 EventSubscriber subscriber)
Subscribes an EventSubscriber to the publication of objects matching a type exactly.

The semantics are the same as subscribeExactly(Class, EventSubscriber), except that the EventService holds a regularly reference, not a WeakReference.

The subscriber will remain subscribed until unsubscribe(Class,EventSubscriber) is called.

Parameters:
eventClass - the class of published objects to listen to
subscriber - The subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribeStrongly

boolean subscribeStrongly(String topic,
                          EventTopicSubscriber subscriber)
Subscribes a subscriber to an event topic name.

The semantics are the same as subscribe(String, EventTopicSubscriber), except that the EventService holds a regularly reference, not a WeakReference.

The subscriber will remain subscribed until unsubscribe(String,EventTopicSubscriber) is called.

Parameters:
topic - the name of the topic listened to
subscriber - The topic subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

subscribeStrongly

boolean subscribeStrongly(Pattern topicPattern,
                          EventTopicSubscriber subscriber)
Subscribes a subscriber to all the event topic names that match a RegEx expression.

The semantics are the same as subscribe(java.util.regex.Pattern, EventTopicSubscriber), except that the EventService holds a regularly reference, not a WeakReference.

The subscriber will remain subscribed until unsubscribe(String,EventTopicSubscriber) is called.

Parameters:
topicPattern - the name of the topic listened to
subscriber - The topic subscriber that will accept the events when published.
Returns:
true if the subscriber was subscribed successfully, false otherwise

unsubscribe

boolean unsubscribe(Class eventClass,
                    EventSubscriber subscriber)
Stop the subscription for a subscriber that is subscribed to a class.

Parameters:
eventClass - the class of published objects to listen to
subscriber - The subscriber that is subscribed to the event. The same reference as the one subscribed.
Returns:
true if the subscriber was subscribed to the event, false if it wasn't

unsubscribeExactly

boolean unsubscribeExactly(Class eventClass,
                           EventSubscriber subscriber)
Stop the subscription for a subscriber that is subscribed to an exact class.

Parameters:
eventClass - the class of published objects to listen to
subscriber - The subscriber that is subscribed to the event. The same reference as the one subscribed.
Returns:
true if the subscriber was subscribed to the event, false if it wasn't

unsubscribe

boolean unsubscribe(String topic,
                    EventTopicSubscriber subscriber)
Stop the subscription for a subscriber that is subscribed to an event topic.

Parameters:
topic - the topic listened to
subscriber - The subscriber that is subscribed to the topic. The same reference as the one subscribed.
Returns:
true if the subscriber was subscribed to the event, false if it wasn't

unsubscribe

boolean unsubscribe(Pattern topicPattern,
                    EventTopicSubscriber subscriber)
Stop the subscription for a subscriber that is subscribed to event topics via a Pattern.

Parameters:
topicPattern - the regex expression matching topics listened to
subscriber - The subscriber that is subscribed to the topic. The same reference as the one subscribed.
Returns:
true if the subscriber was subscribed to the event, false if it wasn't

subscribeVetoListener

boolean subscribeVetoListener(Class eventClass,
                              VetoEventListener vetoListener)
Subscribes a VetoEventListener to publication of event matching a class. Only a WeakReference to the VetoEventListener is held by the EventService.

Use this method to avoid having to call unsubscribe(), though with care since garbage collection semantics is indeterminate. The service will respect the WeakReference semantics. In other words, if the vetoListener has not been garbage collected, then the onEvent will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same VetoEventListener hard reference to stop a subscription immediately.

The service will create the WeakReference on behalf of the caller.

Parameters:
eventClass - the class of published objects that can be vetoed
vetoListener - The VetoEventListener that can determine whether an event is published.
Returns:
true if the VetoEventListener was subscribed successfully, false otherwise

subscribeVetoListenerExactly

boolean subscribeVetoListenerExactly(Class eventClass,
                                     VetoEventListener vetoListener)
Subscribes a VetoEventListener to publication of an exact event class. Only a WeakReference to the VetoEventListener is held by the EventService.

Use this method to avoid having to call unsubscribe(), though with care since garbage collection semantics is indeterminate. The service will respect the WeakReference semantics. In other words, if the vetoListener has not been garbage collected, then the onEvent will be called normally. If the hard reference has been garbage collected, the service will unsubscribe it's WeakReference.

It's allowable to call unsubscribe() with the same VetoEventListener hard reference to stop a subscription immediately.

The service will create the WeakReference on behalf of the caller.

Parameters:
eventClass - the class of published objects that can be vetoed
vetoListener - The vetoListener that can determine whether an event is published.
Returns:
true if the vetoListener was subscribed successfully, false otherwise

subscribeVetoListener

boolean subscribeVetoListener(String topic,
                              VetoTopicEventListener vetoListener)
Subscribes a VetoTopicEventListener to a topic name. Only a WeakReference to the VetoEventListener is held by the EventService.

Parameters:
topic - the name of the topic listened to
vetoListener - The vetoListener that can determine whether an event is published.
Returns:
true if the vetoListener was subscribed successfully, false otherwise

subscribeVetoListener

boolean subscribeVetoListener(Pattern topicPattern,
                              VetoTopicEventListener vetoListener)
Subscribes an VetoTopicEventListener to all the topic names that match the RegEx Pattern. Only a WeakReference to the VetoEventListener is held by the EventService.

Parameters:
topicPattern - the RegEx pattern to match topics with
vetoListener - The vetoListener that can determine whether an event is published.
Returns:
true if the vetoListener was subscribed successfully, false otherwise

subscribeVetoListenerStrongly

boolean subscribeVetoListenerStrongly(Class eventClass,
                                      VetoEventListener vetoListener)
Subscribes a VetoEventListener for an event class and its subclasses. Only a WeakReference to the VetoEventListener is held by the EventService.

The VetoEventListener will remain subscribed until unsubscribeVetoListener(Class,VetoEventListener) is called.

Parameters:
eventClass - the class of published objects to listen to
vetoListener - The vetoListener that will accept the events when published.
Returns:
true if the vetoListener was subscribed successfully, false otherwise

subscribeVetoListenerExactlyStrongly

boolean subscribeVetoListenerExactlyStrongly(Class eventClass,
                                             VetoEventListener vetoListener)
Subscribes a VetoEventListener for an event class (but not its subclasses).

The VetoEventListener will remain subscribed until unsubscribeVetoListener(Class,VetoEventListener) is called.

Parameters:
eventClass - the class of published objects to listen to
vetoListener - The vetoListener that will accept the events when published.
Returns:
true if the vetoListener was subscribed successfully, false otherwise

subscribeVetoListenerStrongly

boolean subscribeVetoListenerStrongly(String topic,
                                      VetoTopicEventListener vetoListener)
Subscribes a VetoEventListener to a topic name.

The VetoEventListener will remain subscribed until unsubscribeVetoListener(String,VetoTopicEventListener) is called.

Parameters:
topic - the name of the topic listened to
vetoListener - The topic vetoListener that will accept or reject publication.
Returns:
true if the vetoListener was subscribed successfully, false otherwise
See Also:
subscribeVetoListenerStrongly(Class,VetoEventListener)

subscribeVetoListenerStrongly

boolean subscribeVetoListenerStrongly(Pattern topicPattern,
                                      VetoTopicEventListener vetoListener)
Subscribes a VetoTopicEventListener to a set of topics that match a RegEx expression.

The VetoEventListener will remain subscribed until unsubscribeVetoListener(Pattern,VetoTopicEventListener) is called.

Parameters:
topicPattern - the RegEx pattern that matches the name of the topics listened to
vetoListener - The topic vetoListener that will accept or reject publication.
Returns:
true if the vetoListener was subscribed successfully, false otherwise
See Also:
subscribeVetoListenerStrongly(Pattern,VetoTopicEventListener)

unsubscribeVetoListener

boolean unsubscribeVetoListener(Class eventClass,
                                VetoEventListener vetoListener)
Stop the subscription for a vetoListener that is subscribed to an event class and its subclasses.

Parameters:
eventClass - the class of published objects that can be vetoed
vetoListener - The vetoListener that will accept or reject publication of an event.
Returns:
true if the vetoListener was subscribed to the event, false if it wasn't

unsubscribeVetoListenerExactly

boolean unsubscribeVetoListenerExactly(Class eventClass,
                                       VetoEventListener vetoListener)
Stop the subscription for a vetoListener that is subscribed to an event class (but not its subclasses).

Parameters:
eventClass - the class of published objects that can be vetoed
vetoListener - The vetoListener that will accept or reject publication of an event.
Returns:
true if the vetoListener was subscribed to the event, false if it wasn't

unsubscribeVetoListener

boolean unsubscribeVetoListener(String topic,
                                VetoTopicEventListener vetoListener)
Stop the subscription for a VetoTopicEventListener that is subscribed to an event topic name.

Parameters:
topic - the name of the topic that is listened to
vetoListener - The vetoListener that can determine whether an event is published on that topic
Returns:
true if the vetoListener was subscribed to the topic, false if it wasn't

unsubscribeVetoListener

boolean unsubscribeVetoListener(Pattern topicPattern,
                                VetoTopicEventListener vetoListener)
Stop the subscription for a VetoTopicEventListener that is subscribed to an event topic RegEx pattern.

Parameters:
topicPattern - the RegEx pattern matching the name of the topics listened to
vetoListener - The vetoListener that can determine whether an event is published on that topic
Returns:
true if the vetoListener was subscribed to the topicPattern, false if it wasn't

getSubscribers

<T> List<T> getSubscribers(Class<T> eventClass)
Union of getSubscribersToClass(Class) and getSubscribersToExactClass(Class)

Parameters:
eventClass - the eventClass of interest
Returns:
the subscribers that will be called when an event of eventClass is published, this includes those subscribed that match by exact class and those that match to a class and its subtypes

getSubscribersToClass

<T> List<T> getSubscribersToClass(Class<T> eventClass)
Gets subscribers that subscribed with the given a class, but not those subscribed exactly to the class.

Parameters:
eventClass - the eventClass of interest
Returns:
the subscribers that are subscribed to match to a class and its subtypes, but not those subscribed by exact class

getSubscribersToExactClass

<T> List<T> getSubscribersToExactClass(Class<T> eventClass)
Gets subscribers that are subscribed exactly to a class, but not those subscribed non-exactly to a class.

Parameters:
eventClass - the eventClass of interest
Returns:
the subscribers that are subscribed by exact class but not those subscribed to match to a class and its subtypes

getSubscribers

<T> List<T> getSubscribers(Type type)
Gets the subscribers that subscribed to a generic type.

Parameters:
type - the type of interest
Returns:
the subscribers that will be called when an event of eventClass is published, this includes those subscribed that match by exact class and those that match to a class and its subtypes

getSubscribers

<T> List<T> getSubscribers(String topic)
Union of getSubscribersByPattern(String) and geSubscribersToTopic(String)

Parameters:
topic - the topic of interest
Returns:
the subscribers that will be called when an event is published on the topic. This includes subscribers subscribed to match the exact topic name and those subscribed by a RegEx Pattern that matches the topic name.

getSubscribersToTopic

<T> List<T> getSubscribersToTopic(String topic)
Get the subscribers that subscribed to a topic.

Parameters:
topic - the topic of interest
Returns:
the subscribers that subscribed to the exact topic name.

getSubscribers

<T> List<T> getSubscribers(Pattern pattern)
Gets the subscribers that subscribed to a regular expression.

Parameters:
pattern - the RegEx pattern that was subscribed to
Returns:
the subscribers that were subscribed to this pattern.

getSubscribersByPattern

<T> List<T> getSubscribersByPattern(String topic)
Gets the subscribers that subscribed with a Pattern that matches the given topic.

Parameters:
topic - a topic to match Patterns against
Returns:
the subscribers that subscribed by a RegEx Pattern that matches the topic name.

getVetoSubscribers

<T> List<T> getVetoSubscribers(Class<T> eventClass)
Gets veto subscribers that subscribed to a given class.

Parameters:
eventClass - the eventClass of interest
Returns:
the veto subscribers that will be called when an event of eventClass or its subclasses is published.

getVetoSubscribersToExactClass

<T> List<T> getVetoSubscribersToExactClass(Class<T> eventClass)
Get veto subscribers that subscribed to a given class exactly.

Parameters:
eventClass - the eventClass of interest
Returns:
the veto subscribers that will be called when an event of eventClass (but not its subclasses) is published.

getVetoSubscribersToClass

<T> List<T> getVetoSubscribersToClass(Class<T> eventClass)
Gets the veto subscribers that subscribed to a class.

Parameters:
eventClass - the eventClass of interest
Returns:
the veto subscribers that are subscribed to the eventClass and its subclasses

getVetoEventListeners

<T> List<T> getVetoEventListeners(String topicOrPattern)
Union of getVetoSubscribersToTopic(String) and getVetoSubscribersByPattern(String) Misnamed method, should be called getVetoSubscribers(String). Will be deprecated in 1.5.

Parameters:
topicOrPattern - the topic or pattern of interest
Returns:
the veto subscribers that will be called when an event is published on the topic.

getVetoSubscribersToTopic

<T> List<T> getVetoSubscribersToTopic(String topic)
Gets the veto subscribers that subscribed to a topic.

Parameters:
topic - the topic of interest
Returns:
the veto subscribers that will be called when an event is published on the topic.

getVetoSubscribers

<T> List<T> getVetoSubscribers(Pattern pattern)
Gets the veto subscribers that subscribed to a regular expression.

Parameters:
pattern - the RegEx pattern for the topic of interest
Returns:
the veto subscribers that were subscribed to this pattern.

getVetoSubscribersByPattern

<T> List<T> getVetoSubscribersByPattern(String topic)
Gets the veto subscribers that are subscribed by pattern that match the topic.

Parameters:
topic - the topic to match the pattern string subscribed to
Returns:
the veto subscribers that subscribed by pattern that will be called when an event is published on the topic.

getVetoSubscribers

<T> List<T> getVetoSubscribers(String topic)
Deprecated. use getVetoSubscribersToTopic instead for direct replacement, or use getVetoEventListeners to get topic and pattern matchers. In EventBus 2.0 this name will replace getVetoEventListeners() and have it's union functionality

Misnamed method for backwards compatibility. Duplicate of getVetoSubscribersToTopic(String). Out of sync with getSubscribers(String).

Parameters:
topic - the topic exactly subscribed to
Returns:
the veto subscribers that are subscribed to the topic.

clearAllSubscribers

void clearAllSubscribers()
Clears all current subscribers and veto subscribers


setDefaultCacheSizePerClassOrTopic

void setDefaultCacheSizePerClassOrTopic(int defaultCacheSizePerClassOrTopic)
Sets the default cache size for each kind of event, default is 0 (no caching).

If this value is set to a positive number, then when an event is published, the EventService caches the event or topic payload data for later retrieval. This allows subscribers to find out what has most recently happened before they subscribed. The cached event(s) are returned from #getLastEvent(Class), #getLastTopicData(String), #getCachedEvents(Class), or #getCachedTopicData(String)

The default can be overridden on a by-event-class or by-topic basis.

Parameters:
defaultCacheSizePerClassOrTopic - the cache size per event

getDefaultCacheSizePerClassOrTopic

int getDefaultCacheSizePerClassOrTopic()
The default number of events or payloads kept per event class or topic

Returns:
the default number of event payloads kept per event class or topic

setCacheSizeForEventClass

void setCacheSizeForEventClass(Class eventClass,
                               int cacheSize)
Set the number of events cached for a particular class of event. By default, no events are cached.

This overrides any setting for the DefaultCacheSizePerClassOrTopic.

Class hierarchy semantics are respected. That is, if there are three events, A, X and Y, and X and Y are both derived from A, then setting the cache size for A applies the cache size for all three. Setting the cache size for X applies to X and leaves the settings for A and Y in tact. Interfaces can be passed to this method, but they only take effect if the cache size of a class or it's superclasses has been set. Just like Class.getInterfaces(), if multiple cache sizes are set, the interface names declared earliest in the implements clause of the eventClass takes effect.

The cache for an event is not adjusted until the next event of that class is published.

Parameters:
eventClass - the class of event
cacheSize - the number of published events to cache for this event

getCacheSizeForEventClass

int getCacheSizeForEventClass(Class eventClass)
Returns the number of events cached for a particular class of event. By default, no events are cached.

This result is computed for a particular class from the values passed to #setCacheSizeForEventClass(Class, int), and respects the class hierarchy.

Parameters:
eventClass - the class of event
Returns:
the maximum size of the event cache for the given event class
See Also:
setCacheSizeForEventClass(Class,int)

setCacheSizeForTopic

void setCacheSizeForTopic(String topicName,
                          int cacheSize)
Set the number of published data objects cached for a particular event topic. By default, no data are cached.

This overrides any setting for the DefaultCacheSizePerClassOrTopic.

Exact topic names take precedence over pattern matching.

The cache for a topic is not adjusted until the next publication on that topic.

Parameters:
topicName - the topic name
cacheSize - the number of published data Objects to cache for this topic

setCacheSizeForTopic

void setCacheSizeForTopic(Pattern pattern,
                          int cacheSize)
Set the number of published data objects cached for a topics matching a pattern. By default, no data are cached.

This overrides any setting for the DefaultCacheSizePerClassOrTopic.

Exact topic names take precedence over pattern matching.

The cache for a topic is not adjusted until the next publication on that topic.

Parameters:
pattern - the pattern matching topic names
cacheSize - the number of data Objects to cache for this topic

getCacheSizeForTopic

int getCacheSizeForTopic(String topic)
Returns the number of cached data objects published on a particular topic.

This result is computed for a particular class from the values passed to #setCacheSizeForEventClass(Class, int), and respects the class hierarchy.

Parameters:
topic - the topic name
Returns:
the maximum size of the data Object cache for the given topic
See Also:
setCacheSizeForTopic(String,int), setCacheSizeForTopic(java.util.regex.Pattern,int)

getLastEvent

<T> T getLastEvent(Class<T> eventClass)
When caching, returns the last event publish for the type supplied.

Parameters:
eventClass - an index into the cache
Returns:
the last event published for this event class, or null if caching is turned off (the default)

getCachedEvents

<T> List<T> getCachedEvents(Class<T> eventClass)
When caching, returns the last set of event published for the type supplied.

Parameters:
eventClass - an index into the cache
Returns:
the last events published for this event class, or null if caching is turned off (the default)

getLastTopicData

Object getLastTopicData(String topic)
When caching, returns the last payload published on the topic name supplied.

Parameters:
topic - an index into the cache
Returns:
the last data Object published on this topic, or null if caching is turned off (the default)

getCachedTopicData

List getCachedTopicData(String topic)
When caching, returns the last set of payload objects published on the topic name supplied.

Parameters:
topic - an index into the cache
Returns:
the last data Objects published on this topic, or null if caching is turned off (the default)

clearCache

void clearCache(Class eventClass)
Clears the event cache for a specific event class or interface and it's any of it's subclasses or implementing classes.

Parameters:
eventClass - the event class to clear the cache for

clearCache

void clearCache(String topic)
Clears the topic data cache for a specific topic name.

Parameters:
topic - the topic name to clear the cache for

clearCache

void clearCache(Pattern pattern)
Clears the topic data cache for all topics that match a particular pattern.

Parameters:
pattern - the pattern to match topic caches to

clearCache

void clearCache()
Clear all event caches for all topics and event.


unsubscribe

boolean unsubscribe(Class eventClass,
                    Object subscribedByProxy)
Stop a subscription for an object that is subscribed with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
eventClass - class this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribeExactly

boolean unsubscribeExactly(Class eventClass,
                           Object subscribedByProxy)
Stop a subscription for an object that is subscribed exactly with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
eventClass - class this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribe

boolean unsubscribe(String topic,
                    Object subscribedByProxy)
Stop a subscription for an object that is subscribed to a topic with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
topic - the topic this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribe

boolean unsubscribe(Pattern pattern,
                    Object subscribedByProxy)
When using annotations, an object may be subscribed by proxy. This unsubscribe method will unsubscribe an object that is subscribed with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
pattern - the RegEx expression this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribeVeto

boolean unsubscribeVeto(Class eventClass,
                        Object subscribedByProxy)
Stop a veto subscription for an object that is subscribed with a ProxySubscriber.

If an object is subscribed by proxy and it implements VetoSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
eventClass - class this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribeVetoExactly

boolean unsubscribeVetoExactly(Class eventClass,
                               Object subscribedByProxy)
Stop a veto subscription for an object that is subscribed exactly with a ProxySubscriber.

If an object is subscribed by proxy and it implements VetoSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
eventClass - class this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribeVeto

boolean unsubscribeVeto(String topic,
                        Object subscribedByProxy)
Stop a veto subscription for an object that is subscribed to a topic with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
topic - the topic this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed

unsubscribeVeto

boolean unsubscribeVeto(Pattern pattern,
                        Object subscribedByProxy)
When using annotations, an object may be subscribed by proxy. This unsubscribe method will unsubscribe an object that is subscribed with a ProxySubscriber.

If an object is subscribed by proxy and it implements EventSubscriber, then the normal unsubscribe methods will still unsubscribe the object.

Parameters:
pattern - the RegEx expression this object is subscribed to by proxy
subscribedByProxy - object subscribed by proxy
Returns:
true if the subscription was cancelled, false if it never existed


Copyright © 2011 Bushe Enterprises, Inc.. All Rights Reserved.