1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.zookeeper.server.watch; 20 21 import java.io.IOException; 22 import org.slf4j.Logger; 23 import org.slf4j.LoggerFactory; 24 25 /** 26 * A factory used to produce the actual watch manager based on the 27 * zookeeper.watchManagerName option. 28 */ 29 public class WatchManagerFactory { 30 31 private static final Logger LOG = LoggerFactory.getLogger(WatchManagerFactory.class); 32 33 public static final String ZOOKEEPER_WATCH_MANAGER_NAME = "zookeeper.watchManagerName"; 34 createWatchManager()35 public static IWatchManager createWatchManager() throws IOException { 36 String watchManagerName = System.getProperty(ZOOKEEPER_WATCH_MANAGER_NAME); 37 if (watchManagerName == null) { 38 watchManagerName = WatchManager.class.getName(); 39 } 40 try { 41 IWatchManager watchManager = (IWatchManager) Class.forName(watchManagerName).getConstructor().newInstance(); 42 LOG.info("Using {} as watch manager", watchManagerName); 43 return watchManager; 44 } catch (Exception e) { 45 IOException ioe = new IOException("Couldn't instantiate " + watchManagerName, e); 46 throw ioe; 47 } 48 } 49 50 } 51