/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.configuration;
import java.io.File;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.net.URL;
import java.util.Iterator;
import java.util.List;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import org.xml.sax.Attributes;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
/**
* This configuration implements the XML properties format introduced in Java
* 5.0, see http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html.
* An XML properties file looks like this:
*
* <pre>
* <?xml version="1.0"?>
* <!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
* <properties>
* <comment>Description of the property list</comment>
* <entry key="key1">value1</entry>
* <entry key="key2">value2</entry>
* <entry key="key3">value3</entry>
* </properties>
* </pre>
*
* The Java 5.0 runtime is not required to use this class. The default encoding
* for this configuration format is UTF-8. Note that unlike
* <code>PropertiesConfiguration</code>, <code>XMLPropertiesConfiguration</code>
* does not support includes.
*
* <em>Note:</em>Configuration objects of this type can be read concurrently
* by multiple threads. However if one of these threads modifies the object,
* synchronization has to be performed manually.
*
* @author Emmanuel Bourg
* @author Alistair Young
* @version $Revision: 548098 $, $Date: 2007-06-17 21:34:03 +0200 (So, 17 Jun 2007) $
* @since 1.1
*/
public class XMLPropertiesConfiguration extends PropertiesConfiguration
{
/**
* The default encoding (UTF-8 as specified by http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html)
*/
private static final String DEFAULT_ENCODING = "UTF-8";
// initialization block to set the encoding before loading the file in the constructors
{
setEncoding(DEFAULT_ENCODING);
}
/**
* Creates an empty XMLPropertyConfiguration object which can be
* used to synthesize a new Properties file by adding values and
* then saving(). An object constructed by this C'tor can not be
* tickled into loading included files because it cannot supply a
* base for relative includes.
*/
public XMLPropertiesConfiguration()
{
super();
}
/**
* Creates and loads the xml properties from the specified file.
* The specified file can contain "include" properties which then
* are loaded and merged into the properties.
*
* @param fileName The name of the properties file to load.
* @throws ConfigurationException Error while loading the properties file
*/
public XMLPropertiesConfiguration(String fileName) throws ConfigurationException
{
super(fileName);
}
/**
* Creates and loads the xml properties from the specified file.
* The specified file can contain "include" properties which then
* are loaded and merged into the properties.
*
* @param file The properties file to load.
* @throws ConfigurationException Error while loading the properties file
*/
public XMLPropertiesConfiguration(File file) throws ConfigurationException
{
super(file);
}
/**
* Creates and loads the xml properties from the specified URL.
* The specified file can contain "include" properties which then
* are loaded and merged into the properties.
*
* @param url The location of the properties file to load.
* @throws ConfigurationException Error while loading the properties file
*/
public XMLPropertiesConfiguration(URL url) throws ConfigurationException
{
super(url);
}
public void load(Reader in) throws ConfigurationException
{
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setNamespaceAware(false);
factory.setValidating(true);
try
{
SAXParser parser = factory.newSAXParser();
XMLReader xmlReader = parser.getXMLReader();
xmlReader.setEntityResolver(new EntityResolver()
{
public InputSource resolveEntity(String publicId, String systemId)
{
return new InputSource(getClass().getClassLoader().getResourceAsStream("properties.dtd"));
}
});
xmlReader.setContentHandler(new XMLPropertiesHandler());
xmlReader.parse(new InputSource(in));
}
catch (Exception e)
{
throw new ConfigurationException("Unable to parse the configuration file", e);
}
// todo: support included properties ?
}
public void save(Writer out) throws ConfigurationException
{
PrintWriter writer = new PrintWriter(out);
String encoding = getEncoding() != null ? getEncoding() : DEFAULT_ENCODING;
writer.println("<?xml version=\"1.0\" encoding=\"" + encoding + "\"?>");
writer.println("<!DOCTYPE properties SYSTEM \"http://java.sun.com/dtd/properties.dtd\">");
writer.println("<properties>");
if (getHeader() != null)
{
writer.println(" <comment>" + StringEscapeUtils.escapeXml(getHeader()) + "</comment>");
}
Iterator keys = getKeys();
while (keys.hasNext())
{
String key = (String) keys.next();
Object value = getProperty(key);
if (value instanceof List)
{
writeProperty(writer, key, (List) value);
}
else
{
writeProperty(writer, key, value);
}
}
writer.println("</properties>");
writer.flush();
}
/**
* Write a property.
*
* @param out the output stream
* @param key the key of the property
* @param value the value of the property
*/
private void writeProperty(PrintWriter out, String key, Object value)
{
// escape the key
String k = StringEscapeUtils.escapeXml(key);
if (value != null)
{
// escape the value
String v = StringEscapeUtils.escapeXml(String.valueOf(value));
v = StringUtils.replace(v, String.valueOf(getListDelimiter()), "\\" + getListDelimiter());
out.println(" <entry key=\"" + k + "\">" + v + "</entry>");
}
else
{
out.println(" <entry key=\"" + k + "\"/>");
}
}
/**
* Write a list property.
*
* @param out the output stream
* @param key the key of the property
* @param values a list with all property values
*/
private void writeProperty(PrintWriter out, String key, List values)
{
for (int i = 0; i < values.size(); i++)
{
writeProperty(out, key, values.get(i));
}
}
/**
* SAX Handler to parse a XML properties file.
*
* @author Alistair Young
* @since 1.2
*/
private class XMLPropertiesHandler extends DefaultHandler
{
/** The key of the current entry being parsed. */
private String key;
/** The value of the current entry being parsed. */
private StringBuffer value = new StringBuffer();
/** Indicates that a comment is being parsed. */
private boolean inCommentElement;
/** Indicates that an entry is being parsed. */
private boolean inEntryElement;
public void startElement(String uri, String localName, String qName, Attributes attrs)
{
if ("comment".equals(qName))
{
inCommentElement = true;
}
if ("entry".equals(qName))
{
key = attrs.getValue("key");
inEntryElement = true;
}
}
public void endElement(String uri, String localName, String qName)
{
if (inCommentElement)
{
// We've just finished a <comment> element so set the header
setHeader(value.toString());
inCommentElement = false;
}
if (inEntryElement)
{
// We've just finished an <entry> element, so add the key/value pair
addProperty(key, value.toString());
inEntryElement = false;
}
// Clear the element value buffer
value = new StringBuffer();
}
public void characters(char[] chars, int start, int length)
{
/**
* We're currently processing an element. All character data from now until
* the next endElement() call will be the data for this element.
*/
value.append(chars, start, length);
}
}
}