+public class DataChangeListener extends AbstractUntypedActor {
+ private static final Logger LOG = LoggerFactory.getLogger(DataChangeListener.class);
+
+ private final AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener;
+ private boolean notificationsEnabled = false;
+
+ public DataChangeListener(AsyncDataChangeListener<YangInstanceIdentifier,
+ NormalizedNode<?, ?>> listener) {
+ this.listener = Preconditions.checkNotNull(listener, "listener should not be null");
+ }
+
+ @Override
+ public void handleReceive(Object message) throws Exception {
+ if(message instanceof DataChanged){
+ dataChanged(message);
+ } else if(message instanceof EnableNotification){
+ enableNotification((EnableNotification) message);
+ }
+ }
+
+ private void enableNotification(EnableNotification message) {
+ notificationsEnabled = message.isEnabled();
+ LOG.debug("{} notifications for listener {}", (notificationsEnabled ? "Enabled" : "Disabled"),
+ listener);
+ }
+
+ private void dataChanged(Object message) {
+
+ // Do nothing if notifications are not enabled
+ if(!notificationsEnabled) {
+ LOG.debug("Notifications not enabled for listener {} - dropping change notification",
+ listener);
+ return;
+ }
+
+ DataChanged reply = (DataChanged) message;
+ AsyncDataChangeEvent<YangInstanceIdentifier, NormalizedNode<?, ?>> change = reply.getChange();
+
+ LOG.debug("Sending change notification {} to listener {}", change, listener);
+
+ this.listener.onDataChanged(change);
+
+ // It seems the sender is never null but it doesn't hurt to check. If the caller passes in
+ // a null sender (ActorRef.noSender()), akka translates that to the deadLetters actor.
+ if(getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
+ getSender().tell(new DataChangedReply(), getSelf());
+ }
+ }
+
+ public static Props props(final AsyncDataChangeListener<YangInstanceIdentifier,
+ NormalizedNode<?, ?>> listener) {
+ return Props.create(new DataChangeListenerCreator(listener));