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</code> wraps a 028 * configuration-collection 029 * {@link org.apache.commons.configuration.Configuration} 030 * instance to provide a <code>Map</code> 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 $Revision: 492216 $, $Date: 2007-01-03 17:51:24 +0100 (Mi, 03 Jan 2007) $ 036 * @since 1.0 037 */ 038 public class ConfigurationMap extends AbstractMap 039 { 040 /** 041 * The <code>Configuration</code> wrapped by this class. 042 */ 043 private Configuration configuration; 044 045 /** 046 * Creates a new instance of a <code>ConfigurationMap</code> 047 * that wraps the specified <code>Configuration</code> 048 * instance. 049 * @param configuration <code>Configuration</code> 050 * instance. 051 */ 052 public ConfigurationMap(Configuration configuration) 053 { 054 this.configuration = configuration; 055 } 056 057 /** 058 * Returns the wrapped <code>Configuration</code> 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 public Set entrySet() 075 { 076 return new ConfigurationSet(configuration); 077 } 078 079 /** 080 * Stores the value for the specified key. The value is stored in the 081 * underlying configuration. 082 * 083 * @param key the key (will be converted to a string) 084 * @param value the value 085 * @return the old value of this key or <b>null</b> if it is new 086 * @see java.util.Map#put(java.lang.Object, java.lang.Object) 087 */ 088 public Object put(Object key, Object value) 089 { 090 String strKey = String.valueOf(key); 091 Object old = configuration.getProperty(strKey); 092 configuration.setProperty(strKey, value); 093 return old; 094 } 095 096 /** 097 * Returns the value of the specified key. The key is converted to a string 098 * and then passed to the underlying configuration. 099 * 100 * @param key the key 101 * @return the value of this key 102 * @see java.util.Map#get(java.lang.Object) 103 */ 104 public Object get(Object key) 105 { 106 return configuration.getProperty(String.valueOf(key)); 107 } 108 109 /** 110 * Set of entries in the map. 111 */ 112 static class ConfigurationSet extends AbstractSet 113 { 114 /** The configuration mapped to this entry set. */ 115 private Configuration configuration; 116 117 /** 118 * A Map entry in the ConfigurationMap. 119 */ 120 private final class Entry implements Map.Entry 121 { 122 /** The key of the map entry. */ 123 private Object key; 124 125 private Entry(Object key) 126 { 127 this.key = key; 128 } 129 130 public Object getKey() 131 { 132 return key; 133 } 134 135 public Object getValue() 136 { 137 return configuration.getProperty((String) key); 138 } 139 140 public Object setValue(Object value) 141 { 142 Object old = getValue(); 143 configuration.setProperty((String) key, value); 144 return old; 145 } 146 } 147 148 /** 149 * Iterator over the entries in the ConfigurationMap. 150 */ 151 private final class ConfigurationSetIterator implements Iterator 152 { 153 /** An iterator over the keys in the configuration. */ 154 private Iterator keys; 155 156 private ConfigurationSetIterator() 157 { 158 keys = configuration.getKeys(); 159 } 160 161 public boolean hasNext() 162 { 163 return keys.hasNext(); 164 } 165 166 public Object next() 167 { 168 return new Entry(keys.next()); 169 } 170 171 public void remove() 172 { 173 keys.remove(); 174 } 175 } 176 177 ConfigurationSet(Configuration configuration) 178 { 179 this.configuration = configuration; 180 } 181 182 /** 183 * @see java.util.Collection#size() 184 */ 185 public int size() 186 { 187 // Ouch. Now _that_ one is expensive... 188 int count = 0; 189 for (Iterator iterator = configuration.getKeys(); iterator.hasNext();) 190 { 191 iterator.next(); 192 count++; 193 } 194 return count; 195 } 196 197 /** 198 * @see java.util.Collection#iterator() 199 */ 200 public Iterator iterator() 201 { 202 return new ConfigurationSetIterator(); 203 } 204 } 205 }