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.io.File; 021 import java.io.PrintWriter; 022 import java.io.Reader; 023 import java.io.Writer; 024 import java.net.URL; 025 import java.util.Iterator; 026 import java.util.List; 027 028 import javax.xml.parsers.SAXParser; 029 import javax.xml.parsers.SAXParserFactory; 030 031 import org.apache.commons.lang.StringEscapeUtils; 032 import org.apache.commons.lang.StringUtils; 033 import org.xml.sax.Attributes; 034 import org.xml.sax.EntityResolver; 035 import org.xml.sax.InputSource; 036 import org.xml.sax.XMLReader; 037 import org.xml.sax.helpers.DefaultHandler; 038 039 /** 040 * This configuration implements the XML properties format introduced in Java 041 * 5.0, see http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html. 042 * An XML properties file looks like this: 043 * 044 * <pre> 045 * <?xml version="1.0"?> 046 * <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd"> 047 * <properties> 048 * <comment>Description of the property list</comment> 049 * <entry key="key1">value1</entry> 050 * <entry key="key2">value2</entry> 051 * <entry key="key3">value3</entry> 052 * </properties> 053 * </pre> 054 * 055 * The Java 5.0 runtime is not required to use this class. The default encoding 056 * for this configuration format is UTF-8. Note that unlike 057 * {@code PropertiesConfiguration}, {@code XMLPropertiesConfiguration} 058 * does not support includes. 059 * 060 * <em>Note:</em>Configuration objects of this type can be read concurrently 061 * by multiple threads. However if one of these threads modifies the object, 062 * synchronization has to be performed manually. 063 * 064 * @author Emmanuel Bourg 065 * @author Alistair Young 066 * @version $Id: XMLPropertiesConfiguration.java 1210207 2011-12-04 20:43:50Z oheger $ 067 * @since 1.1 068 */ 069 public class XMLPropertiesConfiguration extends PropertiesConfiguration 070 { 071 /** 072 * The default encoding (UTF-8 as specified by http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html) 073 */ 074 private static final String DEFAULT_ENCODING = "UTF-8"; 075 076 // initialization block to set the encoding before loading the file in the constructors 077 { 078 setEncoding(DEFAULT_ENCODING); 079 } 080 081 /** 082 * Creates an empty XMLPropertyConfiguration object which can be 083 * used to synthesize a new Properties file by adding values and 084 * then saving(). An object constructed by this C'tor can not be 085 * tickled into loading included files because it cannot supply a 086 * base for relative includes. 087 */ 088 public XMLPropertiesConfiguration() 089 { 090 super(); 091 } 092 093 /** 094 * Creates and loads the xml properties from the specified file. 095 * The specified file can contain "include" properties which then 096 * are loaded and merged into the properties. 097 * 098 * @param fileName The name of the properties file to load. 099 * @throws ConfigurationException Error while loading the properties file 100 */ 101 public XMLPropertiesConfiguration(String fileName) throws ConfigurationException 102 { 103 super(fileName); 104 } 105 106 /** 107 * Creates and loads the xml properties from the specified file. 108 * The specified file can contain "include" properties which then 109 * are loaded and merged into the properties. 110 * 111 * @param file The properties file to load. 112 * @throws ConfigurationException Error while loading the properties file 113 */ 114 public XMLPropertiesConfiguration(File file) throws ConfigurationException 115 { 116 super(file); 117 } 118 119 /** 120 * Creates and loads the xml properties from the specified URL. 121 * The specified file can contain "include" properties which then 122 * are loaded and merged into the properties. 123 * 124 * @param url The location of the properties file to load. 125 * @throws ConfigurationException Error while loading the properties file 126 */ 127 public XMLPropertiesConfiguration(URL url) throws ConfigurationException 128 { 129 super(url); 130 } 131 132 @Override 133 public void load(Reader in) throws ConfigurationException 134 { 135 SAXParserFactory factory = SAXParserFactory.newInstance(); 136 factory.setNamespaceAware(false); 137 factory.setValidating(true); 138 139 try 140 { 141 SAXParser parser = factory.newSAXParser(); 142 143 XMLReader xmlReader = parser.getXMLReader(); 144 xmlReader.setEntityResolver(new EntityResolver() 145 { 146 public InputSource resolveEntity(String publicId, String systemId) 147 { 148 return new InputSource(getClass().getClassLoader().getResourceAsStream("properties.dtd")); 149 } 150 }); 151 xmlReader.setContentHandler(new XMLPropertiesHandler()); 152 xmlReader.parse(new InputSource(in)); 153 } 154 catch (Exception e) 155 { 156 throw new ConfigurationException("Unable to parse the configuration file", e); 157 } 158 159 // todo: support included properties ? 160 } 161 162 @Override 163 public void save(Writer out) throws ConfigurationException 164 { 165 PrintWriter writer = new PrintWriter(out); 166 167 String encoding = getEncoding() != null ? getEncoding() : DEFAULT_ENCODING; 168 writer.println("<?xml version=\"1.0\" encoding=\"" + encoding + "\"?>"); 169 writer.println("<!DOCTYPE properties SYSTEM \"http://java.sun.com/dtd/properties.dtd\">"); 170 writer.println("<properties>"); 171 172 if (getHeader() != null) 173 { 174 writer.println(" <comment>" + StringEscapeUtils.escapeXml(getHeader()) + "</comment>"); 175 } 176 177 Iterator<String> keys = getKeys(); 178 while (keys.hasNext()) 179 { 180 String key = keys.next(); 181 Object value = getProperty(key); 182 183 if (value instanceof List) 184 { 185 writeProperty(writer, key, (List<?>) value); 186 } 187 else 188 { 189 writeProperty(writer, key, value); 190 } 191 } 192 193 writer.println("</properties>"); 194 writer.flush(); 195 } 196 197 /** 198 * Write a property. 199 * 200 * @param out the output stream 201 * @param key the key of the property 202 * @param value the value of the property 203 */ 204 private void writeProperty(PrintWriter out, String key, Object value) 205 { 206 // escape the key 207 String k = StringEscapeUtils.escapeXml(key); 208 209 if (value != null) 210 { 211 // escape the value 212 String v = StringEscapeUtils.escapeXml(String.valueOf(value)); 213 v = StringUtils.replace(v, String.valueOf(getListDelimiter()), "\\" + getListDelimiter()); 214 215 out.println(" <entry key=\"" + k + "\">" + v + "</entry>"); 216 } 217 else 218 { 219 out.println(" <entry key=\"" + k + "\"/>"); 220 } 221 } 222 223 /** 224 * Write a list property. 225 * 226 * @param out the output stream 227 * @param key the key of the property 228 * @param values a list with all property values 229 */ 230 private void writeProperty(PrintWriter out, String key, List<?> values) 231 { 232 for (Object value : values) 233 { 234 writeProperty(out, key, value); 235 } 236 } 237 238 /** 239 * SAX Handler to parse a XML properties file. 240 * 241 * @author Alistair Young 242 * @since 1.2 243 */ 244 private class XMLPropertiesHandler extends DefaultHandler 245 { 246 /** The key of the current entry being parsed. */ 247 private String key; 248 249 /** The value of the current entry being parsed. */ 250 private StringBuilder value = new StringBuilder(); 251 252 /** Indicates that a comment is being parsed. */ 253 private boolean inCommentElement; 254 255 /** Indicates that an entry is being parsed. */ 256 private boolean inEntryElement; 257 258 @Override 259 public void startElement(String uri, String localName, String qName, Attributes attrs) 260 { 261 if ("comment".equals(qName)) 262 { 263 inCommentElement = true; 264 } 265 266 if ("entry".equals(qName)) 267 { 268 key = attrs.getValue("key"); 269 inEntryElement = true; 270 } 271 } 272 273 @Override 274 public void endElement(String uri, String localName, String qName) 275 { 276 if (inCommentElement) 277 { 278 // We've just finished a <comment> element so set the header 279 setHeader(value.toString()); 280 inCommentElement = false; 281 } 282 283 if (inEntryElement) 284 { 285 // We've just finished an <entry> element, so add the key/value pair 286 addProperty(key, value.toString()); 287 inEntryElement = false; 288 } 289 290 // Clear the element value buffer 291 value = new StringBuilder(); 292 } 293 294 @Override 295 public void characters(char[] chars, int start, int length) 296 { 297 /** 298 * We're currently processing an element. All character data from now until 299 * the next endElement() call will be the data for this element. 300 */ 301 value.append(chars, start, length); 302 } 303 } 304 }