2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.controller.md.sal.binding.api;
10 import javax.annotation.Nonnull;
11 import org.opendaylight.yangtools.concepts.ListenerRegistration;
12 import org.opendaylight.yangtools.yang.binding.DataObject;
15 * A {@link BindingService} which allows users to register for changes to a
18 public interface DataTreeChangeService extends BindingService {
20 * Registers a {@link DataTreeChangeListener} to receive
21 * notifications when data changes under a given path in the conceptual data
24 * You are able to register for notifications for any node or subtree
25 * which can be represented using {@link DataTreeIdentifier}.
28 * You are able to register for data change notifications for a subtree or leaf
29 * even if it does not exist. You will receive notification once that node is
32 * If there is any pre-existing data in the data tree for the path for which you are
33 * registering, you will receive an initial data change event, which will
34 * contain all pre-existing data, marked as created.
37 * This method returns a {@link ListenerRegistration} object. To
38 * "unregister" your listener for changes call the {@link ListenerRegistration#close()}
39 * method on the returned object.
41 * You MUST explicitly unregister your listener when you no longer want to receive
42 * notifications. This is especially true in OSGi environments, where failure to
43 * do so during bundle shutdown can lead to stale listeners being still registered.
46 * Data tree identifier of the subtree which should be watched for
49 * Listener instance which is being registered
50 * @return Listener registration object, which may be used to unregister
51 * your listener using {@link ListenerRegistration#close()} to stop
52 * delivery of change events.
54 @Nonnull <T extends DataObject,L extends DataTreeChangeListener<T>> ListenerRegistration<L> registerDataTreeChangeListener(@Nonnull DataTreeIdentifier<T> treeId, @Nonnull L listener);