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.ArrayList; 021import java.util.Collection; 022import java.util.Iterator; 023import java.util.LinkedHashMap; 024import java.util.List; 025import java.util.Map; 026 027import org.apache.commons.configuration2.ex.ConfigurationRuntimeException; 028 029/** 030 * Basic configuration class. Stores the configuration data but does not 031 * provide any load or save functions. If you want to load your Configuration 032 * from a file use PropertiesConfiguration or XmlConfiguration. 033 * 034 * This class extends normal Java properties by adding the possibility 035 * to use the same key many times concatenating the value strings 036 * instead of overwriting them. 037 * 038 * @author <a href="mailto:stefano@apache.org">Stefano Mazzocchi</a> 039 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a> 040 * @author <a href="mailto:daveb@miceda-data">Dave Bryson</a> 041 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> 042 * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a> 043 * @author <a href="mailto:kjohnson@transparent.com">Kent Johnson</a> 044 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> 045 * @author <a href="mailto:ipriha@surfeu.fi">Ilkka Priha</a> 046 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> 047 * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a> 048 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 049 * @author <a href="mailto:ksh@scand.com">Konstantin Shaposhnikov</a> 050 * @version $Id: BaseConfiguration.java 1790899 2017-04-10 21:56:46Z ggregory $ 051 */ 052public class BaseConfiguration extends AbstractConfiguration implements Cloneable 053{ 054 /** stores the configuration key-value pairs */ 055 private Map<String, Object> store = new LinkedHashMap<>(); 056 057 /** 058 * Adds a key/value pair to the map. This routine does no magic morphing. 059 * It ensures the keylist is maintained 060 * 061 * @param key key to use for mapping 062 * @param value object to store 063 */ 064 @Override 065 protected void addPropertyDirect(String key, Object value) 066 { 067 Object previousValue = getPropertyInternal(key); 068 069 if (previousValue == null) 070 { 071 store.put(key, value); 072 } 073 else if (previousValue instanceof List) 074 { 075 // safe to case because we have created the lists ourselves 076 @SuppressWarnings("unchecked") 077 List<Object> valueList = (List<Object>) previousValue; 078 // the value is added to the existing list 079 valueList.add(value); 080 } 081 else 082 { 083 // the previous value is replaced by a list containing the previous value and the new value 084 List<Object> list = new ArrayList<>(); 085 list.add(previousValue); 086 list.add(value); 087 088 store.put(key, list); 089 } 090 } 091 092 /** 093 * Read property from underlying map. 094 * 095 * @param key key to use for mapping 096 * 097 * @return object associated with the given configuration key. 098 */ 099 @Override 100 protected Object getPropertyInternal(String key) 101 { 102 return store.get(key); 103 } 104 105 /** 106 * Check if the configuration is empty 107 * 108 * @return {@code true} if Configuration is empty, 109 * {@code false} otherwise. 110 */ 111 @Override 112 protected boolean isEmptyInternal() 113 { 114 return store.isEmpty(); 115 } 116 117 /** 118 * check if the configuration contains the key 119 * 120 * @param key the configuration key 121 * 122 * @return {@code true} if Configuration contain given key, 123 * {@code false} otherwise. 124 */ 125 @Override 126 protected boolean containsKeyInternal(String key) 127 { 128 return store.containsKey(key); 129 } 130 131 /** 132 * Clear a property in the configuration. 133 * 134 * @param key the key to remove along with corresponding value. 135 */ 136 @Override 137 protected void clearPropertyDirect(String key) 138 { 139 store.remove(key); 140 } 141 142 @Override 143 protected void clearInternal() 144 { 145 store.clear(); 146 } 147 148 /** 149 * {@inheritDoc} This implementation obtains the size directly from the map 150 * used as data store. So this is a rather efficient implementation. 151 */ 152 @Override 153 protected int sizeInternal() 154 { 155 return store.size(); 156 } 157 158 /** 159 * Get the list of the keys contained in the configuration 160 * repository. 161 * 162 * @return An Iterator. 163 */ 164 @Override 165 protected Iterator<String> getKeysInternal() 166 { 167 return store.keySet().iterator(); 168 } 169 170 /** 171 * Creates a copy of this object. This implementation will create a deep 172 * clone, i.e. the map that stores the properties is cloned, too. So changes 173 * performed at the copy won't affect the original and vice versa. 174 * 175 * @return the copy 176 * @since 1.3 177 */ 178 @Override 179 public Object clone() 180 { 181 try 182 { 183 BaseConfiguration copy = (BaseConfiguration) super.clone(); 184 cloneStore(copy); 185 copy.cloneInterpolator(this); 186 187 return copy; 188 } 189 catch (CloneNotSupportedException cex) 190 { 191 // should not happen 192 throw new ConfigurationRuntimeException(cex); 193 } 194 } 195 196 /** 197 * Clones the internal map with the data of this configuration. 198 * 199 * @param copy the copy created by the {@code clone()} method 200 * @throws CloneNotSupportedException if the map cannot be cloned 201 */ 202 private void cloneStore(BaseConfiguration copy) 203 throws CloneNotSupportedException 204 { 205 // This is safe because the type of the map is known 206 @SuppressWarnings("unchecked") 207 Map<String, Object> clonedStore = (Map<String, Object>) ConfigurationUtils.clone(store); 208 copy.store = clonedStore; 209 210 // Handle collections in the map; they have to be cloned, too 211 for (Map.Entry<String, Object> e : store.entrySet()) 212 { 213 if (e.getValue() instanceof Collection) 214 { 215 // This is safe because the collections were created by ourselves 216 @SuppressWarnings("unchecked") 217 Collection<String> strList = (Collection<String>) e.getValue(); 218 copy.store.put(e.getKey(), new ArrayList<>(strList)); 219 } 220 } 221 } 222}