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 * @version $Id: ConfigurationMap.java 1624601 2014-09-12 18:04:36Z oheger $ 036 * @since 1.0 037 */ 038public class ConfigurationMap extends AbstractMap<Object, Object> 039{ 040 /** 041 * The {@code Configuration} wrapped by this class. 042 */ 043 private final 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 final 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 final Object key; 127 128 private Entry(Object key) 129 { 130 this.key = key; 131 } 132 133 @Override 134 public Object getKey() 135 { 136 return key; 137 } 138 139 @Override 140 public Object getValue() 141 { 142 return configuration.getProperty((String) key); 143 } 144 145 @Override 146 public Object setValue(Object value) 147 { 148 Object old = getValue(); 149 configuration.setProperty((String) key, value); 150 return old; 151 } 152 } 153 154 /** 155 * Iterator over the entries in the ConfigurationMap. 156 */ 157 private final class ConfigurationSetIterator implements Iterator<Map.Entry<Object, Object>> 158 { 159 /** An iterator over the keys in the configuration. */ 160 private final Iterator<String> keys; 161 162 private ConfigurationSetIterator() 163 { 164 keys = configuration.getKeys(); 165 } 166 167 @Override 168 public boolean hasNext() 169 { 170 return keys.hasNext(); 171 } 172 173 @Override 174 public Map.Entry<Object, Object> next() 175 { 176 return new Entry(keys.next()); 177 } 178 179 @Override 180 public void remove() 181 { 182 keys.remove(); 183 } 184 } 185 186 ConfigurationSet(Configuration configuration) 187 { 188 this.configuration = configuration; 189 } 190 191 /** 192 * @see java.util.Collection#size() 193 */ 194 @Override 195 public int size() 196 { 197 // Ouch. Now _that_ one is expensive... 198 int count = 0; 199 for (Iterator<String> iterator = configuration.getKeys(); iterator.hasNext();) 200 { 201 iterator.next(); 202 count++; 203 } 204 return count; 205 } 206 207 /** 208 * @see java.util.Collection#iterator() 209 */ 210 @Override 211 public Iterator<Map.Entry<Object, Object>> iterator() 212 { 213 return new ConfigurationSetIterator(); 214 } 215 } 216}