content: /**
   * Copyright 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 com.alibaba.wasp.zookeeper;
  
  import com.alibaba.wasp.conf.WaspConfiguration;
  import org.apache.hadoop.conf.Configuration;
  
  import java.util.Map.Entry;
  import java.util.Properties;
  
  /**
   * Tool for reading a ZooKeeper server from Wasp XML configuration producing
   * the '-server host:port' argument to pass ZooKeeperMain.  This program
   * emits either '-server HOST:PORT" where HOST is one of the zk ensemble
   * members plus zk client port OR it emits '' if no zk servers found (Yes,
   * it emits '-server' too).
   */
  public class ZooKeeperMainServerArg {
    public String parse(final Configuration c) {
      Properties zkProps = ZKConfig.makeZKProps(c);
      String host = null;
      String clientPort = null;
      for (Entry<Object, Object> entry: zkProps.entrySet()) {
        String key = entry.getKey().toString().trim();
        String value = entry.getValue().toString().trim();
        if (key.startsWith("server.") && host == null) {
          String[] parts = value.split(":");
          host = parts[0];
        } else if (key.endsWith("clientPort")) {
          clientPort = value;
        }
        if (host != null && clientPort != null) break;
      }
      return host != null && clientPort != null? host + ":" + clientPort: null;
    }
  
    /**
     * Run the tool.
     * @param args Command line arguments. First arg is path to zookeepers file.
     */
    public static void main(String args[]) {
      Configuration conf = WaspConfiguration.create();
      String hostport = new ZooKeeperMainServerArg().parse(conf);
      System.out.println((hostport == null || hostport.length() == 0)? "":
        "-server " + hostport);
    }
  }
  