1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.hadoop.hbase.util; 20 21 import com.google.common.collect.Lists; 22 23 import org.apache.commons.lang.StringUtils; 24 import org.apache.hadoop.conf.Configuration; 25 import org.apache.hadoop.hbase.classification.InterfaceAudience; 26 import org.apache.hadoop.hbase.classification.InterfaceStability; 27 28 import java.util.AbstractMap; 29 import java.util.Collection; 30 import java.util.List; 31 import java.util.Map; 32 33 /** 34 * Utilities for storing more complex collection types in 35 * {@link org.apache.hadoop.conf.Configuration} instances. 36 */ 37 @InterfaceAudience.Public 38 @InterfaceStability.Evolving 39 public final class ConfigurationUtil { 40 // TODO: hopefully this is a good delimiter; it's not in the base64 alphabet, 41 // nor is it valid for paths 42 public static final char KVP_DELIMITER = '^'; 43 44 // Disallow instantiation 45 private ConfigurationUtil() { 46 47 } 48 49 /** 50 * Store a collection of Map.Entry's in conf, with each entry separated by ',' 51 * and key values delimited by {@link #KVP_DELIMITER} 52 * 53 * @param conf configuration to store the collection in 54 * @param key overall key to store keyValues under 55 * @param keyValues kvps to be stored under key in conf 56 */ 57 public static void setKeyValues(Configuration conf, String key, 58 Collection<Map.Entry<String, String>> keyValues) { 59 setKeyValues(conf, key, keyValues, KVP_DELIMITER); 60 } 61 62 /** 63 * Store a collection of Map.Entry's in conf, with each entry separated by ',' 64 * and key values delimited by delimiter. 65 * 66 * @param conf configuration to store the collection in 67 * @param key overall key to store keyValues under 68 * @param keyValues kvps to be stored under key in conf 69 * @param delimiter character used to separate each kvp 70 */ 71 public static void setKeyValues(Configuration conf, String key, 72 Collection<Map.Entry<String, String>> keyValues, char delimiter) { 73 List<String> serializedKvps = Lists.newArrayList(); 74 75 for (Map.Entry<String, String> kvp : keyValues) { 76 serializedKvps.add(kvp.getKey() + delimiter + kvp.getValue()); 77 } 78 79 conf.setStrings(key, serializedKvps.toArray(new String[serializedKvps.size()])); 80 } 81 82 /** 83 * Retrieve a list of key value pairs from configuration, stored under the provided key 84 * 85 * @param conf configuration to retrieve kvps from 86 * @param key key under which the key values are stored 87 * @return the list of kvps stored under key in conf, or null if the key isn't present. 88 * @see #setKeyValues(Configuration, String, Collection, char) 89 */ 90 public static List<Map.Entry<String, String>> getKeyValues(Configuration conf, String key) { 91 return getKeyValues(conf, key, KVP_DELIMITER); 92 } 93 94 /** 95 * Retrieve a list of key value pairs from configuration, stored under the provided key 96 * 97 * @param conf configuration to retrieve kvps from 98 * @param key key under which the key values are stored 99 * @param delimiter character used to separate each kvp 100 * @return the list of kvps stored under key in conf, or null if the key isn't present. 101 * @see #setKeyValues(Configuration, String, Collection, char) 102 */ 103 public static List<Map.Entry<String, String>> getKeyValues(Configuration conf, String key, 104 char delimiter) { 105 String[] kvps = conf.getStrings(key); 106 107 if (kvps == null) { 108 return null; 109 } 110 111 List<Map.Entry<String, String>> rtn = Lists.newArrayList(); 112 113 for (String kvp : kvps) { 114 String[] splitKvp = StringUtils.split(kvp, delimiter); 115 116 if (splitKvp.length != 2) { 117 throw new IllegalArgumentException( 118 "Expected key value pair for configuration key '" + key + "'" + " to be of form '<key>" 119 + delimiter + "<value>; was " + kvp + " instead"); 120 } 121 122 rtn.add(new AbstractMap.SimpleImmutableEntry<String, String>(splitKvp[0], splitKvp[1])); 123 } 124 return rtn; 125 } 126 }