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.metrics.spi;
023    
024    import java.net.InetSocketAddress;
025    import java.util.ArrayList;
026    import java.util.List;
027    
028    import org.apache.hadoop.classification.InterfaceAudience;
029    import org.apache.hadoop.classification.InterfaceStability;
030    import org.apache.hadoop.net.NetUtils;
031    
032    /**
033     * Static utility methods
034     */
035    @InterfaceAudience.Public
036    @InterfaceStability.Evolving
037    public class Util {
038        
039      /**
040       * This class is not intended to be instantiated
041       */
042      private Util() {}
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       * @return a list of InetSocketAddress objects.
050       */
051      public static List<InetSocketAddress> parse(String specs, int defaultPort) {
052        List<InetSocketAddress> result = new ArrayList<InetSocketAddress>(1);
053        if (specs == null) {
054          result.add(new InetSocketAddress("localhost", defaultPort));
055        }
056        else {
057          String[] specStrings = specs.split("[ ,]+");
058          for (String specString : specStrings) {
059            result.add(NetUtils.createSocketAddr(specString, defaultPort));
060          }
061        }
062        return result;
063      }
064        
065    }