org.eclipse.scada.core.subscription

Class SubscriptionManager<T>

java.lang.Object

org.eclipse.scada.core.subscription.SubscriptionManager<T>

Direct Known Subclasses:

ListenableSubscriptionManager

public class SubscriptionManager<T>
extends Object

Manage subscriptions.

Author:

Jens Reimann <jens.reimann@th4-systems.com>

Constructor Summary

Constructors

Constructor and Description
SubscriptionManager()
SubscriptionManager(SubscriptionValidator<T> validator)

Method Summary

Modifier and Type	Method and Description
Set<T>	getAllGrantedTopics() Get all topics whose subscription is in granted state.
int	getSubscriptionCount() Get the number of subscriptions currently registered
void	setSource(T topic, SubscriptionSource<T> source) Set a source for a topic.
void	subscribe(T topic, SubscriptionListener<T> listener) Subscribe to a topic.
void	subscribe(T topic, SubscriptionListener<T> listener, Object hint) Subscribe to a topic with a hint
protected void	topicSubscriptionAdded(T topic) Gets called when somebody subscribed to a topic that was not subscribed before
protected void	topicSubscriptionRemoved(T topic) Get called when somebody unsubscribed from a topic and it was the last subscription
void	unsubscribe(T topic, SubscriptionListener<T> listener)
void	unsubscribeAll(SubscriptionListener<T> listener) Unsubscribe from all subscriptions that the listener has subscribed to

Methods inherited from class java.lang.Object

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

Constructor Detail

SubscriptionManager

public SubscriptionManager(SubscriptionValidator<T> validator)

SubscriptionManager

public SubscriptionManager()

Method Detail

unsubscribeAll

public void unsubscribeAll(SubscriptionListener<T> listener)

Unsubscribe from all subscriptions that the listener has subscribed to

Parameters:

listener - the listener to unsubscribe

subscribe

public void subscribe(T topic,
                      SubscriptionListener<T> listener)
               throws ValidationException

Subscribe to a topic.

Parameters:

topic - The topic to which the subscription should be made

listener - The listener which will receive the events

Throws:

ValidationException - thrown if the subscription cannot be established (e.g. the topic is invalid)

subscribe

public void subscribe(T topic,
                      SubscriptionListener<T> listener,
                      Object hint)
               throws ValidationException

Subscribe to a topic with a hint

Parameters:

topic - The topic to which the subscription should be made

listener - The listener which will receive the events

hint - The hint is specific to the topic

Throws:

ValidationException - thrown if the subscription cannot be established (e.g. the topic is invalid)

unsubscribe

public void unsubscribe(T topic,
                        SubscriptionListener<T> listener)

topicSubscriptionAdded

protected void topicSubscriptionAdded(T topic)

Gets called when somebody subscribed to a topic that was not subscribed before

Parameters:

topic - the topic

topicSubscriptionRemoved

protected void topicSubscriptionRemoved(T topic)

Get called when somebody unsubscribed from a topic and it was the last subscription

Parameters:

topic - the topic

setSource

public void setSource(T topic,
                      SubscriptionSource<T> source)

Set a source for a topic. This will cause all granted subscriptions to switch to connected for this source

Parameters:

topic - the topic

source - the source to set

getSubscriptionCount

public int getSubscriptionCount()

Get the number of subscriptions currently registered

Returns:

the number of subscriptions

getAllGrantedTopics

public Set<T> getAllGrantedTopics()

Get all topics whose subscription is in granted state.

Returns:

The list of topics whose subscription is in granted state.