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