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    
022    package org.apache.hadoop.metrics2.util;
023    
024    import java.net.InetSocketAddress;
025    import java.util.List;
026    
027    import com.google.common.collect.Lists;
028    
029    import org.apache.hadoop.classification.InterfaceAudience;
030    import org.apache.hadoop.classification.InterfaceStability;
031    
032    /**
033     * Helpers to handle server addresses
034     */
035    @InterfaceAudience.Public
036    @InterfaceStability.Evolving
037    public class Servers {
038      /**
039       * This class is not intended to be instantiated
040       */
041      private Servers() {}
042    
043      /**
044       * Parses a space and/or comma separated sequence of server specifications
045       * of the form <i>hostname</i> or <i>hostname:port</i>.  If
046       * the specs string is null, defaults to localhost:defaultPort.
047       *
048       * @param specs   server specs (see description)
049       * @param defaultPort the default port if not specified
050       * @return a list of InetSocketAddress objects.
051       */
052      public static List<InetSocketAddress> parse(String specs, int defaultPort) {
053        List<InetSocketAddress> result = Lists.newArrayList();
054        if (specs == null) {
055          result.add(new InetSocketAddress("localhost", defaultPort));
056        }
057        else {
058          String[] specStrings = specs.split("[ ,]+");
059          for (String specString : specStrings) {
060            int colon = specString.indexOf(':');
061            if (colon < 0 || colon == specString.length() - 1) {
062              result.add(new InetSocketAddress(specString, defaultPort));
063            } else {
064              String hostname = specString.substring(0, colon);
065              int port = Integer.parseInt(specString.substring(colon+1));
066              result.add(new InetSocketAddress(hostname, port));
067            }
068          }
069        }
070        return result;
071      }
072    }