| /** |
| * Copyright 2010 The Apache Software Foundation |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.zookeeper; |
| |
| |
| /** |
| * Base class for internal listeners of ZooKeeper events. |
| * |
| * The {@link ZooKeeperWatcher} for a process will execute the appropriate |
| * methods of implementations of this class. In order to receive events from |
| * the watcher, every listener must register itself via {@link ZooKeeperWatcher#registerListener}. |
| * |
| * Subclasses need only override those methods in which they are interested. |
| * |
| * Note that the watcher will be blocked when invoking methods in listeners so |
| * they must not be long-running. |
| */ |
| public class ZooKeeperListener { |
| |
| // Reference to the zk watcher which also contains configuration and constants |
| protected ZooKeeperWatcher watcher; |
| |
| /** |
| * Construct a ZooKeeper event listener. |
| */ |
| public ZooKeeperListener(ZooKeeperWatcher watcher) { |
| this.watcher = watcher; |
| } |
| |
| /** |
| * Called when a new node has been created. |
| * @param path full path of the new node |
| */ |
| public void nodeCreated(String path) { |
| // no-op |
| } |
| |
| /** |
| * Called when a node has been deleted |
| * @param path full path of the deleted node |
| */ |
| public void nodeDeleted(String path) { |
| // no-op |
| } |
| |
| /** |
| * Called when an existing node has changed data. |
| * @param path full path of the updated node |
| */ |
| public void nodeDataChanged(String path) { |
| // no-op |
| } |
| |
| /** |
| * Called when an existing node has a child node added or removed. |
| * @param path full path of the node whose children have changed |
| */ |
| public void nodeChildrenChanged(String path) { |
| // no-op |
| } |
| } |