1 /*
   2  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal.util.xml;
  27 
  28 import java.io.*;
  29 import java.nio.charset.Charset;
  30 import java.util.InvalidPropertiesFormatException;
  31 import java.util.Map.Entry;
  32 import java.util.Properties;
  33 import jdk.internal.org.xml.sax.Attributes;
  34 import jdk.internal.org.xml.sax.InputSource;
  35 import jdk.internal.org.xml.sax.SAXException;
  36 import jdk.internal.org.xml.sax.SAXParseException;
  37 import jdk.internal.org.xml.sax.helpers.DefaultHandler;
  38 import jdk.internal.util.xml.impl.SAXParserImpl;
  39 import jdk.internal.util.xml.impl.XMLStreamWriterImpl;
  40 
  41 /**
  42  * A class used to aid in Properties load and save in XML. This class is
  43  * re-implemented using a subset of SAX
  44  *
  45  * @author Joe Wang
  46  * @since 1.8
  47  */
  48 public class PropertiesDefaultHandler extends DefaultHandler {
  49 
  50     // Elements specified in the properties.dtd
  51     private static final String ELEMENT_ROOT = "properties";
  52     private static final String ELEMENT_COMMENT = "comment";
  53     private static final String ELEMENT_ENTRY = "entry";
  54     private static final String ATTR_KEY = "key";
  55     // The required DTD URI for exported properties
  56     private static final String PROPS_DTD_DECL =
  57         "<!DOCTYPE properties SYSTEM \"http://java.sun.com/dtd/properties.dtd\">";
  58     private static final String PROPS_DTD_URI =
  59         "http://java.sun.com/dtd/properties.dtd";
  60     private static final String PROPS_DTD =
  61         "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
  62             + "<!-- DTD for properties -->"
  63             + "<!ELEMENT properties ( comment?, entry* ) >"
  64             + "<!ATTLIST properties"
  65             + " version CDATA #FIXED \"1.0\">"
  66             + "<!ELEMENT comment (#PCDATA) >"
  67             + "<!ELEMENT entry (#PCDATA) >"
  68             + "<!ATTLIST entry "
  69             + " key CDATA #REQUIRED>";
  70     /**
  71      * Version number for the format of exported properties files.
  72      */
  73     private static final String EXTERNAL_XML_VERSION = "1.0";
  74     private Properties properties;
  75 
  76     public void load(Properties props, InputStream in)
  77         throws IOException, InvalidPropertiesFormatException, UnsupportedEncodingException
  78     {
  79         this.properties = props;
  80 
  81         try {
  82             SAXParser parser = new SAXParserImpl();
  83             parser.parse(in, this);
  84         } catch (SAXException saxe) {
  85             throw new InvalidPropertiesFormatException(saxe);
  86         }
  87 
  88         /**
  89          * String xmlVersion = propertiesElement.getAttribute("version"); if
  90          * (xmlVersion.compareTo(EXTERNAL_XML_VERSION) > 0) throw new
  91          * InvalidPropertiesFormatException( "Exported Properties file format
  92          * version " + xmlVersion + " is not supported. This java installation
  93          * can read" + " versions " + EXTERNAL_XML_VERSION + " or older. You" +
  94          * " may need to install a newer version of JDK.");
  95          */
  96     }
  97 
  98     public void store(Properties props, OutputStream os, String comment, Charset charset)
  99         throws IOException
 100     {
 101         try {
 102             XMLStreamWriter writer = new XMLStreamWriterImpl(os, charset);
 103             writer.writeStartDocument();
 104             writer.writeDTD(PROPS_DTD_DECL);
 105             writer.writeStartElement(ELEMENT_ROOT);
 106             if (comment != null && !comment.isEmpty()) {
 107                 writer.writeStartElement(ELEMENT_COMMENT);
 108                 writer.writeCharacters(comment);
 109                 writer.writeEndElement();
 110             }
 111 
 112             synchronized(props) {
 113                 for (Entry<Object, Object> e : props.entrySet()) {
 114                     final Object k = e.getKey();
 115                     final Object v = e.getValue();
 116                     if (k instanceof String && v instanceof String) {
 117                         writer.writeStartElement(ELEMENT_ENTRY);
 118                         writer.writeAttribute(ATTR_KEY, (String)k);
 119                         writer.writeCharacters((String)v);
 120                         writer.writeEndElement();
 121                     }
 122                 }
 123             }
 124 
 125             writer.writeEndElement();
 126             writer.writeEndDocument();
 127             writer.flush();
 128         } catch (XMLStreamException e) {
 129             if (e.getCause() instanceof UnsupportedEncodingException) {
 130                 throw (UnsupportedEncodingException) e.getCause();
 131             }
 132             throw new IOException(e);
 133         }
 134 
 135     }
 136     ////////////////////////////////////////////////////////////////////
 137     // Validate while parsing
 138     ////////////////////////////////////////////////////////////////////
 139     static final String ALLOWED_ELEMENTS = "comment, entry";
 140     static final String ALLOWED_COMMENT = "comment";
 141     ////////////////////////////////////////////////////////////////////
 142     // Handler methods
 143     ////////////////////////////////////////////////////////////////////
 144     StringBuilder buf = new StringBuilder();
 145     boolean sawRoot = false; // whether a valid root element exists
 146     boolean sawComment = false;
 147     boolean validEntry = false;
 148     String key;
 149     String rootElm;
 150 
 151     @Override
 152     public void startElement(String uri, String localName, String qName, Attributes attributes)
 153         throws SAXException
 154     {
 155         if (sawRoot) {
 156             if (!ALLOWED_ELEMENTS.contains(qName)) {
 157                 fatalError(new SAXParseException("Element type \"" + qName + "\" must be declared.", null));
 158             }
 159         } else {
 160             // check whether the root has been declared in the DTD
 161             if (rootElm == null) {
 162                 fatalError(new SAXParseException("An XML properties document must contain"
 163                     + " the DOCTYPE declaration as defined by java.util.Properties.", null));
 164             }
 165 
 166             // check whether the element name matches the declaration
 167             if (!rootElm.equals(qName)) {
 168                 fatalError(new SAXParseException("Document root element \"" + qName
 169                     + "\", must match DOCTYPE root \"" + rootElm + "\"", null));
 170             }
 171 
 172             // this is a valid root element
 173             sawRoot = true;
 174         }
 175 
 176         if (qName.equals(ELEMENT_ENTRY)) {
 177             validEntry = true;
 178             key = attributes.getValue(ATTR_KEY);
 179             if (key == null) {
 180                 fatalError(new SAXParseException("Attribute \"key\" is required and " +
 181                     "must be specified for element type \"entry\"", null));
 182             }
 183         } else if (qName.equals(ALLOWED_COMMENT)) {
 184             if (sawComment) {
 185                 fatalError(new SAXParseException("Only one comment element may be allowed. "
 186                     + "The content of element type \"properties\" must match \"(comment?,entry*)\"", null));
 187             }
 188             sawComment = true;
 189         }
 190     }
 191 
 192     @Override
 193     public void characters(char[] ch, int start, int length) throws SAXException {
 194         if (validEntry) {
 195             buf.append(ch, start, length);
 196         }
 197     }
 198 
 199     @Override
 200     public void endElement(String uri, String localName, String qName) throws SAXException {
 201         if (!ALLOWED_ELEMENTS.contains(qName) && !ELEMENT_ROOT.equals(qName)) {
 202             fatalError(new SAXParseException("Element: " + qName +
 203                 " is invalid, must match  \"(comment?,entry*)\".", null));
 204         }
 205 
 206         if (validEntry) {
 207             properties.setProperty(key, buf.toString());
 208             buf.delete(0, buf.length());
 209             validEntry = false;
 210         }
 211     }
 212 
 213     @Override
 214     public InputSource resolveEntity(String pubid, String sysid)
 215         throws SAXException, IOException {
 216         {
 217             if (sysid.equals(PROPS_DTD_URI)) {
 218                 // The properties DTD is known to the handler, no need to parse it
 219                 return null;
 220             }
 221             throw new SAXException("Invalid system identifier: " + sysid);
 222         }
 223     }
 224 
 225     @Override
 226     public void error(SAXParseException x) throws SAXException {
 227         throw x;
 228     }
 229 
 230     @Override
 231     public void fatalError(SAXParseException x) throws SAXException {
 232         throw x;
 233     }
 234 
 235     @Override
 236     public void warning(SAXParseException x) throws SAXException {
 237         throw x;
 238     }
 239 
 240     // SAX2 extension from DTDHandler
 241 
 242     @Override
 243     public void startDTD (String name, String publicId, String systemId) throws SAXException
 244     {
 245         if (!ELEMENT_ROOT.equals(name) || !PROPS_DTD_URI.equals(systemId)) {
 246             fatalError(new SAXParseException("An XML properties document must contain"
 247                 + " the DOCTYPE declaration as defined by java.util.Properties.", null));
 248         }
 249         rootElm = name;
 250     }
 251 
 252     @Override
 253     public void startInternalSub () throws SAXException
 254     {
 255         fatalError(new SAXParseException("Internal DTD subset is not allowed. " +
 256             "The Properties XML document must have the following DOCTYPE declaration: \n" +
 257             PROPS_DTD_DECL, null));
 258     }
 259 }