Java tutorial
/* * 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.giraph.zk; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.Options; import org.apache.commons.cli.PosixParser; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.util.Tool; import org.apache.hadoop.util.ToolRunner; import org.apache.zookeeper.CreateMode; import org.apache.zookeeper.WatchedEvent; import org.apache.zookeeper.Watcher; import org.apache.zookeeper.ZooDefs; import static java.lang.System.out; /** A utility class to be used to create a ZooKeeper node */ public class ZooKeeperNodeCreator implements Tool, Watcher { /** The configuration */ private Configuration conf; @Override public void setConf(Configuration conf) { this.conf = conf; } @Override public Configuration getConf() { return conf; } @Override public int run(String[] args) throws Exception { Options options = new Options(); options.addOption("zk", "zkServer", true, "List of host:port ZooKeeper servers"); options.addOption("n", "zkNode", true, "ZooKeeper node to create"); HelpFormatter formatter = new HelpFormatter(); if (args.length == 0) { formatter.printHelp(getClass().getName(), options, true); return 0; } CommandLineParser parser = new PosixParser(); CommandLine cmd = parser.parse(options, args); ZooKeeperExt zkExt = new ZooKeeperExt(cmd.getOptionValue("zkServer"), 30 * 1000, 5, 1000, this); zkExt.createExt(cmd.getOptionValue("zkNode"), new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, true); return 0; } @Override public void process(WatchedEvent event) { out.println("process: ZK event received: " + event); } /** * Entry point from shell script * @param args the command line arguments */ public static void main(String[] args) throws Exception { System.exit(ToolRunner.run(new ZooKeeperNodeCreator(), args)); } }