Interface StatusEvent
- All Known Subinterfaces:
SubjectStatusEvent
Represents an event that is raised when there is a change in the status of the backend.
Usage in DataSource source applications
A StatusEvent
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 all
subjects. For example, if the back end system that feeds data to a
DataProvider
goes down, the
DataProvider
should raise a
StatusEvent
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.
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Method Summary
Modifier and TypeMethodDescriptionGets the subject status message.Gets the status of the subject.
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Method Details
-
getStatus
SubjectStatus getStatus()Gets the status of the subject.- Returns:
- The status.
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getMessage
String getMessage()Gets the subject status message.- Returns:
- A string representing the subject status.
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