001/*
002 * Util.java
003 *
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021
022package org.apache.hadoop.metrics2.util;
023
024import java.net.InetSocketAddress;
025import java.util.List;
026
027import com.google.common.collect.Lists;
028
029import org.apache.hadoop.classification.InterfaceAudience;
030import org.apache.hadoop.classification.InterfaceStability;
031import org.apache.hadoop.net.NetUtils;
032
033/**
034 * Helpers to handle server addresses
035 */
036@InterfaceAudience.Public
037@InterfaceStability.Evolving
038public class Servers {
039  /**
040   * This class is not intended to be instantiated
041   */
042  private Servers() {}
043
044  /**
045   * Parses a space and/or comma separated sequence of server specifications
046   * of the form <i>hostname</i> or <i>hostname:port</i>.  If
047   * the specs string is null, defaults to localhost:defaultPort.
048   *
049   * @param specs   server specs (see description)
050   * @param defaultPort the default port if not specified
051   * @return a list of InetSocketAddress objects.
052   */
053  public static List<InetSocketAddress> parse(String specs, int defaultPort) {
054    List<InetSocketAddress> result = Lists.newArrayList();
055    if (specs == null) {
056      result.add(new InetSocketAddress("localhost", defaultPort));
057    }
058    else {
059      String[] specStrings = specs.split("[ ,]+");
060      for (String specString : specStrings) {
061        result.add(NetUtils.createSocketAddr(specString, defaultPort));
062      }
063    }
064    return result;
065  }
066}