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 018package org.apache.commons.configuration2; 019 020import java.util.AbstractMap; 021import java.util.AbstractSet; 022import java.util.Iterator; 023import java.util.Map; 024import java.util.Set; 025 026/** 027 * <p>The {@code ConfigurationMap} wraps a 028 * configuration-collection 029 * {@link org.apache.commons.configuration2.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 * @since 1.0 036 */ 037public class ConfigurationMap extends AbstractMap<Object, Object> 038{ 039 /** 040 * The {@code Configuration} wrapped by this class. 041 */ 042 private final Configuration configuration; 043 044 /** 045 * Creates a new instance of a {@code ConfigurationMap} 046 * that wraps the specified {@code Configuration} 047 * instance. 048 * @param configuration {@code Configuration} 049 * instance. 050 */ 051 public ConfigurationMap(final Configuration configuration) 052 { 053 this.configuration = configuration; 054 } 055 056 /** 057 * Returns the wrapped {@code Configuration} object. 058 * 059 * @return the wrapped configuration 060 * @since 1.2 061 */ 062 public Configuration getConfiguration() 063 { 064 return configuration; 065 } 066 067 /** 068 * Returns a set with the entries contained in this configuration-based map. 069 * 070 * @return a set with the contained entries 071 * @see java.util.Map#entrySet() 072 */ 073 @Override 074 public Set<Map.Entry<Object, Object>> 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 @Override 089 public Object put(final Object key, final Object value) 090 { 091 final String strKey = String.valueOf(key); 092 final Object old = configuration.getProperty(strKey); 093 configuration.setProperty(strKey, value); 094 return old; 095 } 096 097 /** 098 * Returns the value of the specified key. The key is converted to a string 099 * and then passed to the underlying configuration. 100 * 101 * @param key the key 102 * @return the value of this key 103 * @see java.util.Map#get(java.lang.Object) 104 */ 105 @Override 106 public Object get(final Object key) 107 { 108 return configuration.getProperty(String.valueOf(key)); 109 } 110 111 /** 112 * Set of entries in the map. 113 */ 114 static class ConfigurationSet extends AbstractSet<Map.Entry<Object, Object>> 115 { 116 /** The configuration mapped to this entry set. */ 117 private final Configuration configuration; 118 119 /** 120 * A Map entry in the ConfigurationMap. 121 */ 122 private final class Entry implements Map.Entry<Object, Object> 123 { 124 /** The key of the map entry. */ 125 private final Object key; 126 127 private Entry(final Object key) 128 { 129 this.key = key; 130 } 131 132 @Override 133 public Object getKey() 134 { 135 return key; 136 } 137 138 @Override 139 public Object getValue() 140 { 141 return configuration.getProperty((String) key); 142 } 143 144 @Override 145 public Object setValue(final Object value) 146 { 147 final Object old = getValue(); 148 configuration.setProperty((String) key, value); 149 return old; 150 } 151 } 152 153 /** 154 * Iterator over the entries in the ConfigurationMap. 155 */ 156 private final class ConfigurationSetIterator implements Iterator<Map.Entry<Object, Object>> 157 { 158 /** An iterator over the keys in the configuration. */ 159 private final Iterator<String> keys; 160 161 private ConfigurationSetIterator() 162 { 163 keys = configuration.getKeys(); 164 } 165 166 @Override 167 public boolean hasNext() 168 { 169 return keys.hasNext(); 170 } 171 172 @Override 173 public Map.Entry<Object, Object> next() 174 { 175 return new Entry(keys.next()); 176 } 177 178 @Override 179 public void remove() 180 { 181 keys.remove(); 182 } 183 } 184 185 ConfigurationSet(final Configuration configuration) 186 { 187 this.configuration = configuration; 188 } 189 190 /** 191 * @see java.util.Collection#size() 192 */ 193 @Override 194 public int size() 195 { 196 // Ouch. Now _that_ one is expensive... 197 int count = 0; 198 for (final Iterator<String> iterator = configuration.getKeys(); iterator.hasNext();) 199 { 200 iterator.next(); 201 count++; 202 } 203 return count; 204 } 205 206 /** 207 * @see java.util.Collection#iterator() 208 */ 209 @Override 210 public Iterator<Map.Entry<Object, Object>> iterator() 211 { 212 return new ConfigurationSetIterator(); 213 } 214 } 215}