com.spotify.dns

Interface ChangeNotifier<T>

Type Parameters:

T - The records type

All Known Subinterfaces:

ChangeNotifierFactory.RunnableChangeNotifier<T>

public interface ChangeNotifier<T>

A change notifier represents a watched lookup from a DnsSrvWatcher.

The records can be of any type. Usually something that directly reflects what your application will use the records for.

A ChangeNotifier.Listener can be attached to listen to change events on the watched set of records.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	ChangeNotifier.ChangeNotification<T> A change event containing the current and previous set of records.
static interface	ChangeNotifier.Listener<T> A listener which will be called when the set of records change

Method Summary

Modifier and Type	Method and Description
void	close() Close this ChangeNotifier, releasing any resources allocated.
Set<T>	current() Get the current set of records.
void	setListener(ChangeNotifier.Listener<T> listener, boolean fire) Set a listener to be called when the set of records change.

Method Detail

current

Set<T> current()

Get the current set of records.

Returns:

The current set of records

setListener

void setListener(ChangeNotifier.Listener<T> listener,
                 boolean fire)

Set a listener to be called when the set of records change.

One one listener can be added. Multiple calls to this method is an error.

Parameters:

listener - The listener to set

fire - Fire the notification event immediately. Can be used to ensure that no updates are missed when setting the listener

Throws:

IllegalStateException - if called more than once

close

void close()

Close this ChangeNotifier, releasing any resources allocated. Once closed, no more ChangeNotifier.Listener events will be fired. Implementations of ChangeNotifier are not allowed to throw checked exceptions from close().