com.caplin.motif.datasource

Class CachedPublisher

java.lang.Object

com.caplin.motif.datasource.CachedPublisher

public class CachedPublisher
extends Object

Provides a mechanism for publishing messages and events; maintains a cache so that new subscribers can be serviced with existing messages automatically.

Messages can be published using publishMessage(com.caplin.datasource.messaging.Message)

Field Summary

Fields

Modifier and Type	Field and Description
protected com.caplin.datasource.publisher.Publisher	publisher

Method Summary

Modifier and Type	Method and Description
void	clearCache() Clears the cache held by this publisher.
com.caplin.datasource.messaging.MessageFactory	getMessageFactory() Returns the message factory that can be used to create messages, error and status events.
void	publishErrorEvent(com.caplin.datasource.SubjectErrorEvent subjectErrorEvent) Publishes a SubjectErrorEvent to all peers subscribed to the subject of the event.
void	publishMessage(com.caplin.datasource.messaging.Message message) Publishes a message to all peers that are subscribed to the subject of the message.
void	publishStatusEvent(com.caplin.datasource.SubjectStatusEvent subjectStatusEvent) Publishes a SubjectStatusEvent to all peers subscribed to the subject of the event.
void	sendNotFound(String subject) Sends a NotFound and removes any subscription from the cache.
void	sendNotStale(String subject) Sets the status of a subject to NotStale.
void	sendStale(String subject) Sets the status of a subject to Stale.
void	sendUnavailable(String subject) Sends a Unavailable and removes any subscription from the cache.

Methods inherited from class java.lang.Object

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

Field Detail

publisher

protected final com.caplin.datasource.publisher.Publisher publisher

Method Detail

publishMessage

public void publishMessage(com.caplin.datasource.messaging.Message message)

Publishes a message to all peers that are subscribed to the subject of the message. The cache will be updated with the new fields from this message, but will also retain any fields that are present in the previously sent message that are not present in this message.

Parameters:

message - The message to publish.

sendNotFound

public void sendNotFound(String subject)

Sends a NotFound and removes any subscription from the cache.

Parameters:

subject - The subject to send the NotFound for.

sendUnavailable

public void sendUnavailable(String subject)

Sends a Unavailable and removes any subscription from the cache.

Parameters:

subject - The subject to send the Unavailable for.

sendStale

public void sendStale(String subject)

Sets the status of a subject to Stale.

If the subject is not currently marked as Stale, a Stale message will be sent. If the subject is already marked as Stale when this method is called then no message is sent.

Parameters:

subject - The subject to set the status to Stale for.

See Also:

sendStale(String)

sendNotStale

public void sendNotStale(String subject)

Sets the status of a subject to NotStale.

If the subject is not currently marked as NotStale, a NotStale message will be sent. If the subject is already marked as NotStale when this method is called then no message is sent.

Parameters:

subject - The subject to set the status to NotStale for.

See Also:

sendNotStale(String)

publishErrorEvent

public void publishErrorEvent(com.caplin.datasource.SubjectErrorEvent subjectErrorEvent)

Publishes a SubjectErrorEvent to all peers subscribed to the subject of the event.

Parameters:

subjectErrorEvent - The error event to publish.

See Also:

SubjectErrorEvent

publishStatusEvent

public void publishStatusEvent(com.caplin.datasource.SubjectStatusEvent subjectStatusEvent)

Publishes a SubjectStatusEvent to all peers subscribed to the subject of the event.

Parameters:

subjectStatusEvent - The status event to publish.

See Also:

SubjectStatusEvent

getMessageFactory

public com.caplin.datasource.messaging.MessageFactory getMessageFactory()

Returns the message factory that can be used to create messages, error and status events.

Returns:

The MessageFactory for this DataSource.

clearCache

public void clearCache()

Clears the cache held by this publisher. It's important to clear the cache whenever there is a status event received by the DataSource.