001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018 package org.apache.commons.configuration; 019 020 import java.util.AbstractMap; 021 import java.util.AbstractSet; 022 import java.util.Iterator; 023 import java.util.Map; 024 import java.util.Set; 025 026 /** 027 * <p>The {@code ConfigurationMap} wraps a 028 * configuration-collection 029 * {@link org.apache.commons.configuration.Configuration} 030 * instance to provide a {@code Map} interface.</p> 031 * 032 * <p><em>Note:</em> This implementation is incomplete.</p> 033 * 034 * @author <a href="mailto:ricardo.gladwell@btinternet.com">Ricardo Gladwell</a> 035 * @version $Id: ConfigurationMap.java 1208794 2011-11-30 21:17:44Z oheger $ 036 * @since 1.0 037 */ 038 public class ConfigurationMap extends AbstractMap<Object, Object> 039 { 040 /** 041 * The {@code Configuration} wrapped by this class. 042 */ 043 private Configuration configuration; 044 045 /** 046 * Creates a new instance of a {@code ConfigurationMap} 047 * that wraps the specified {@code Configuration} 048 * instance. 049 * @param configuration {@code Configuration} 050 * instance. 051 */ 052 public ConfigurationMap(Configuration configuration) 053 { 054 this.configuration = configuration; 055 } 056 057 /** 058 * Returns the wrapped {@code Configuration} object. 059 * 060 * @return the wrapped configuration 061 * @since 1.2 062 */ 063 public Configuration getConfiguration() 064 { 065 return configuration; 066 } 067 068 /** 069 * Returns a set with the entries contained in this configuration-based map. 070 * 071 * @return a set with the contained entries 072 * @see java.util.Map#entrySet() 073 */ 074 @Override 075 public Set<Map.Entry<Object, Object>> entrySet() 076 { 077 return new ConfigurationSet(configuration); 078 } 079 080 /** 081 * Stores the value for the specified key. The value is stored in the 082 * underlying configuration. 083 * 084 * @param key the key (will be converted to a string) 085 * @param value the value 086 * @return the old value of this key or <b>null</b> if it is new 087 * @see java.util.Map#put(java.lang.Object, java.lang.Object) 088 */ 089 @Override 090 public Object put(Object key, Object value) 091 { 092 String strKey = String.valueOf(key); 093 Object old = configuration.getProperty(strKey); 094 configuration.setProperty(strKey, value); 095 return old; 096 } 097 098 /** 099 * Returns the value of the specified key. The key is converted to a string 100 * and then passed to the underlying configuration. 101 * 102 * @param key the key 103 * @return the value of this key 104 * @see java.util.Map#get(java.lang.Object) 105 */ 106 @Override 107 public Object get(Object key) 108 { 109 return configuration.getProperty(String.valueOf(key)); 110 } 111 112 /** 113 * Set of entries in the map. 114 */ 115 static class ConfigurationSet extends AbstractSet<Map.Entry<Object, Object>> 116 { 117 /** The configuration mapped to this entry set. */ 118 private Configuration configuration; 119 120 /** 121 * A Map entry in the ConfigurationMap. 122 */ 123 private final class Entry implements Map.Entry<Object, Object> 124 { 125 /** The key of the map entry. */ 126 private Object key; 127 128 private Entry(Object key) 129 { 130 this.key = key; 131 } 132 133 public Object getKey() 134 { 135 return key; 136 } 137 138 public Object getValue() 139 { 140 return configuration.getProperty((String) key); 141 } 142 143 public Object setValue(Object value) 144 { 145 Object old = getValue(); 146 configuration.setProperty((String) key, value); 147 return old; 148 } 149 } 150 151 /** 152 * Iterator over the entries in the ConfigurationMap. 153 */ 154 private final class ConfigurationSetIterator implements Iterator<Map.Entry<Object, Object>> 155 { 156 /** An iterator over the keys in the configuration. */ 157 private Iterator<String> keys; 158 159 private ConfigurationSetIterator() 160 { 161 keys = configuration.getKeys(); 162 } 163 164 public boolean hasNext() 165 { 166 return keys.hasNext(); 167 } 168 169 public Map.Entry<Object, Object> next() 170 { 171 return new Entry(keys.next()); 172 } 173 174 public void remove() 175 { 176 keys.remove(); 177 } 178 } 179 180 ConfigurationSet(Configuration configuration) 181 { 182 this.configuration = configuration; 183 } 184 185 /** 186 * @see java.util.Collection#size() 187 */ 188 @Override 189 public int size() 190 { 191 // Ouch. Now _that_ one is expensive... 192 int count = 0; 193 for (Iterator<String> iterator = configuration.getKeys(); iterator.hasNext();) 194 { 195 iterator.next(); 196 count++; 197 } 198 return count; 199 } 200 201 /** 202 * @see java.util.Collection#iterator() 203 */ 204 @Override 205 public Iterator<Map.Entry<Object, Object>> iterator() 206 { 207 return new ConfigurationSetIterator(); 208 } 209 } 210 }