com.caplin.datasource

Interface SubjectStatusEvent

public interface SubjectStatusEvent

Represents an event that is raised when there is a change in the status of a subject.

Usage in DataSource source applications

A SubjectStatusEvent can be raised by a source application (that is, a DataSource application sending data to its DataSource peers). A DataProvider in the application creates the SubjectStatusEvent to indicate to peers the status of their subscription to a subject. For example, if the back end system that feeds data to a DataProvider goes down, the DataProvider should raise a SubjectStatusEvent with a with a SubjectStatus of SubjectStatus.Stale to indicate to the peer that the data it has is not completely up-to-date. When an update is subsequently received from the backend data feed, then the DataProvider should raise a SubjectStatusEvent with a SubjectStatus of SubjectStatus.Ok to indicate to the peer that the data it has is now up to date.

Usage in DataSource sink applications

A SubjectStatusEvent can be received by a sink application (that is, a DataSource application receiving data from its DataSource peers). Such events are received through the SubscriptionListener.subjectStatusReceived(com.caplin.datasource.subscription.Subscription, Peer, SubjectStatusEvent) callback on SubscriptionListener.

You do not have to implement this interface yourself. Instances can be created by calling the MessageFactory.createSubjectStatusEvent(String, SubjectStatus, String) method on the MessageFactory that is available on the Publisher interface.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	getMessage() Gets the subject status message.
SubjectStatus	getStatus() Gets the status of the subject.
java.lang.String	getSubject() Gets the subject that this SubjectStatusEvent relates to.

Method Detail

getSubject

java.lang.String getSubject()

Gets the subject that this SubjectStatusEvent relates to.

Returns:

The subject.

getStatus

SubjectStatus getStatus()

Gets the status of the subject.

Returns:

The status.

getMessage

java.lang.String getMessage()

Gets the subject status message.

Returns:

A string representing the subject status.