1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/java/util/prefs/XmlSupport.java Mon Jun 22 18:07:11 2009 +0200
1.3 @@ -0,0 +1,421 @@
1.4 +/*
1.5 + * Copyright 2002-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Sun designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Sun in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.25 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.26 + * have any questions.
1.27 + */
1.28 +
1.29 +package java.util.prefs;
1.30 +
1.31 +import java.util.*;
1.32 +import java.io.*;
1.33 +import javax.xml.parsers.*;
1.34 +import javax.xml.transform.*;
1.35 +import javax.xml.transform.dom.*;
1.36 +import javax.xml.transform.stream.*;
1.37 +import org.xml.sax.*;
1.38 +import org.w3c.dom.*;
1.39 +
1.40 +/**
1.41 + * XML Support for java.util.prefs. Methods to import and export preference
1.42 + * nodes and subtrees.
1.43 + *
1.44 + * @author Josh Bloch and Mark Reinhold
1.45 + * @see Preferences
1.46 + * @since 1.4
1.47 + */
1.48 +class XmlSupport {
1.49 + // The required DTD URI for exported preferences
1.50 + private static final String PREFS_DTD_URI =
1.51 + "http://java.sun.com/dtd/preferences.dtd";
1.52 +
1.53 + // The actual DTD corresponding to the URI
1.54 + private static final String PREFS_DTD =
1.55 + "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
1.56 +
1.57 + "<!-- DTD for preferences -->" +
1.58 +
1.59 + "<!ELEMENT preferences (root) >" +
1.60 + "<!ATTLIST preferences" +
1.61 + " EXTERNAL_XML_VERSION CDATA \"0.0\" >" +
1.62 +
1.63 + "<!ELEMENT root (map, node*) >" +
1.64 + "<!ATTLIST root" +
1.65 + " type (system|user) #REQUIRED >" +
1.66 +
1.67 + "<!ELEMENT node (map, node*) >" +
1.68 + "<!ATTLIST node" +
1.69 + " name CDATA #REQUIRED >" +
1.70 +
1.71 + "<!ELEMENT map (entry*) >" +
1.72 + "<!ATTLIST map" +
1.73 + " MAP_XML_VERSION CDATA \"0.0\" >" +
1.74 + "<!ELEMENT entry EMPTY >" +
1.75 + "<!ATTLIST entry" +
1.76 + " key CDATA #REQUIRED" +
1.77 + " value CDATA #REQUIRED >" ;
1.78 + /**
1.79 + * Version number for the format exported preferences files.
1.80 + */
1.81 + private static final String EXTERNAL_XML_VERSION = "1.0";
1.82 +
1.83 + /*
1.84 + * Version number for the internal map files.
1.85 + */
1.86 + private static final String MAP_XML_VERSION = "1.0";
1.87 +
1.88 + /**
1.89 + * Export the specified preferences node and, if subTree is true, all
1.90 + * subnodes, to the specified output stream. Preferences are exported as
1.91 + * an XML document conforming to the definition in the Preferences spec.
1.92 + *
1.93 + * @throws IOException if writing to the specified output stream
1.94 + * results in an <tt>IOException</tt>.
1.95 + * @throws BackingStoreException if preference data cannot be read from
1.96 + * backing store.
1.97 + * @throws IllegalStateException if this node (or an ancestor) has been
1.98 + * removed with the {@link #removeNode()} method.
1.99 + */
1.100 + static void export(OutputStream os, final Preferences p, boolean subTree)
1.101 + throws IOException, BackingStoreException {
1.102 + if (((AbstractPreferences)p).isRemoved())
1.103 + throw new IllegalStateException("Node has been removed");
1.104 + Document doc = createPrefsDoc("preferences");
1.105 + Element preferences = doc.getDocumentElement() ;
1.106 + preferences.setAttribute("EXTERNAL_XML_VERSION", EXTERNAL_XML_VERSION);
1.107 + Element xmlRoot = (Element)
1.108 + preferences.appendChild(doc.createElement("root"));
1.109 + xmlRoot.setAttribute("type", (p.isUserNode() ? "user" : "system"));
1.110 +
1.111 + // Get bottom-up list of nodes from p to root, excluding root
1.112 + List ancestors = new ArrayList();
1.113 +
1.114 + for (Preferences kid = p, dad = kid.parent(); dad != null;
1.115 + kid = dad, dad = kid.parent()) {
1.116 + ancestors.add(kid);
1.117 + }
1.118 + Element e = xmlRoot;
1.119 + for (int i=ancestors.size()-1; i >= 0; i--) {
1.120 + e.appendChild(doc.createElement("map"));
1.121 + e = (Element) e.appendChild(doc.createElement("node"));
1.122 + e.setAttribute("name", ((Preferences)ancestors.get(i)).name());
1.123 + }
1.124 + putPreferencesInXml(e, doc, p, subTree);
1.125 +
1.126 + writeDoc(doc, os);
1.127 + }
1.128 +
1.129 + /**
1.130 + * Put the preferences in the specified Preferences node into the
1.131 + * specified XML element which is assumed to represent a node
1.132 + * in the specified XML document which is assumed to conform to
1.133 + * PREFS_DTD. If subTree is true, create children of the specified
1.134 + * XML node conforming to all of the children of the specified
1.135 + * Preferences node and recurse.
1.136 + *
1.137 + * @throws BackingStoreException if it is not possible to read
1.138 + * the preferences or children out of the specified
1.139 + * preferences node.
1.140 + */
1.141 + private static void putPreferencesInXml(Element elt, Document doc,
1.142 + Preferences prefs, boolean subTree) throws BackingStoreException
1.143 + {
1.144 + Preferences[] kidsCopy = null;
1.145 + String[] kidNames = null;
1.146 +
1.147 + // Node is locked to export its contents and get a
1.148 + // copy of children, then lock is released,
1.149 + // and, if subTree = true, recursive calls are made on children
1.150 + synchronized (((AbstractPreferences)prefs).lock) {
1.151 + // Check if this node was concurrently removed. If yes
1.152 + // remove it from XML Document and return.
1.153 + if (((AbstractPreferences)prefs).isRemoved()) {
1.154 + elt.getParentNode().removeChild(elt);
1.155 + return;
1.156 + }
1.157 + // Put map in xml element
1.158 + String[] keys = prefs.keys();
1.159 + Element map = (Element) elt.appendChild(doc.createElement("map"));
1.160 + for (int i=0; i<keys.length; i++) {
1.161 + Element entry = (Element)
1.162 + map.appendChild(doc.createElement("entry"));
1.163 + entry.setAttribute("key", keys[i]);
1.164 + // NEXT STATEMENT THROWS NULL PTR EXC INSTEAD OF ASSERT FAIL
1.165 + entry.setAttribute("value", prefs.get(keys[i], null));
1.166 + }
1.167 + // Recurse if appropriate
1.168 + if (subTree) {
1.169 + /* Get a copy of kids while lock is held */
1.170 + kidNames = prefs.childrenNames();
1.171 + kidsCopy = new Preferences[kidNames.length];
1.172 + for (int i = 0; i < kidNames.length; i++)
1.173 + kidsCopy[i] = prefs.node(kidNames[i]);
1.174 + }
1.175 + // release lock
1.176 + }
1.177 +
1.178 + if (subTree) {
1.179 + for (int i=0; i < kidNames.length; i++) {
1.180 + Element xmlKid = (Element)
1.181 + elt.appendChild(doc.createElement("node"));
1.182 + xmlKid.setAttribute("name", kidNames[i]);
1.183 + putPreferencesInXml(xmlKid, doc, kidsCopy[i], subTree);
1.184 + }
1.185 + }
1.186 + }
1.187 +
1.188 + /**
1.189 + * Import preferences from the specified input stream, which is assumed
1.190 + * to contain an XML document in the format described in the Preferences
1.191 + * spec.
1.192 + *
1.193 + * @throws IOException if reading from the specified output stream
1.194 + * results in an <tt>IOException</tt>.
1.195 + * @throws InvalidPreferencesFormatException Data on input stream does not
1.196 + * constitute a valid XML document with the mandated document type.
1.197 + */
1.198 + static void importPreferences(InputStream is)
1.199 + throws IOException, InvalidPreferencesFormatException
1.200 + {
1.201 + try {
1.202 + Document doc = loadPrefsDoc(is);
1.203 + String xmlVersion =
1.204 + doc.getDocumentElement().getAttribute("EXTERNAL_XML_VERSION");
1.205 + if (xmlVersion.compareTo(EXTERNAL_XML_VERSION) > 0)
1.206 + throw new InvalidPreferencesFormatException(
1.207 + "Exported preferences file format version " + xmlVersion +
1.208 + " is not supported. This java installation can read" +
1.209 + " versions " + EXTERNAL_XML_VERSION + " or older. You may need" +
1.210 + " to install a newer version of JDK.");
1.211 +
1.212 + Element xmlRoot = (Element) doc.getDocumentElement().
1.213 + getChildNodes().item(0);
1.214 + Preferences prefsRoot =
1.215 + (xmlRoot.getAttribute("type").equals("user") ?
1.216 + Preferences.userRoot() : Preferences.systemRoot());
1.217 + ImportSubtree(prefsRoot, xmlRoot);
1.218 + } catch(SAXException e) {
1.219 + throw new InvalidPreferencesFormatException(e);
1.220 + }
1.221 + }
1.222 +
1.223 + /**
1.224 + * Create a new prefs XML document.
1.225 + */
1.226 + private static Document createPrefsDoc( String qname ) {
1.227 + try {
1.228 + DOMImplementation di = DocumentBuilderFactory.newInstance().
1.229 + newDocumentBuilder().getDOMImplementation();
1.230 + DocumentType dt = di.createDocumentType(qname, null, PREFS_DTD_URI);
1.231 + return di.createDocument(null, qname, dt);
1.232 + } catch(ParserConfigurationException e) {
1.233 + throw new AssertionError(e);
1.234 + }
1.235 + }
1.236 +
1.237 + /**
1.238 + * Load an XML document from specified input stream, which must
1.239 + * have the requisite DTD URI.
1.240 + */
1.241 + private static Document loadPrefsDoc(InputStream in)
1.242 + throws SAXException, IOException
1.243 + {
1.244 + DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
1.245 + dbf.setIgnoringElementContentWhitespace(true);
1.246 + dbf.setValidating(true);
1.247 + dbf.setCoalescing(true);
1.248 + dbf.setIgnoringComments(true);
1.249 + try {
1.250 + DocumentBuilder db = dbf.newDocumentBuilder();
1.251 + db.setEntityResolver(new Resolver());
1.252 + db.setErrorHandler(new EH());
1.253 + return db.parse(new InputSource(in));
1.254 + } catch (ParserConfigurationException e) {
1.255 + throw new AssertionError(e);
1.256 + }
1.257 + }
1.258 +
1.259 + /**
1.260 + * Write XML document to the specified output stream.
1.261 + */
1.262 + private static final void writeDoc(Document doc, OutputStream out)
1.263 + throws IOException
1.264 + {
1.265 + try {
1.266 + TransformerFactory tf = TransformerFactory.newInstance();
1.267 + try {
1.268 + tf.setAttribute("indent-number", new Integer(2));
1.269 + } catch (IllegalArgumentException iae) {
1.270 + //Ignore the IAE. Should not fail the writeout even the
1.271 + //transformer provider does not support "indent-number".
1.272 + }
1.273 + Transformer t = tf.newTransformer();
1.274 + t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId());
1.275 + t.setOutputProperty(OutputKeys.INDENT, "yes");
1.276 + //Transformer resets the "indent" info if the "result" is a StreamResult with
1.277 + //an OutputStream object embedded, creating a Writer object on top of that
1.278 + //OutputStream object however works.
1.279 + t.transform(new DOMSource(doc),
1.280 + new StreamResult(new BufferedWriter(new OutputStreamWriter(out, "UTF-8"))));
1.281 + } catch(TransformerException e) {
1.282 + throw new AssertionError(e);
1.283 + }
1.284 + }
1.285 +
1.286 + /**
1.287 + * Recursively traverse the specified preferences node and store
1.288 + * the described preferences into the system or current user
1.289 + * preferences tree, as appropriate.
1.290 + */
1.291 + private static void ImportSubtree(Preferences prefsNode, Element xmlNode) {
1.292 + NodeList xmlKids = xmlNode.getChildNodes();
1.293 + int numXmlKids = xmlKids.getLength();
1.294 + /*
1.295 + * We first lock the node, import its contents and get
1.296 + * child nodes. Then we unlock the node and go to children
1.297 + * Since some of the children might have been concurrently
1.298 + * deleted we check for this.
1.299 + */
1.300 + Preferences[] prefsKids;
1.301 + /* Lock the node */
1.302 + synchronized (((AbstractPreferences)prefsNode).lock) {
1.303 + //If removed, return silently
1.304 + if (((AbstractPreferences)prefsNode).isRemoved())
1.305 + return;
1.306 +
1.307 + // Import any preferences at this node
1.308 + Element firstXmlKid = (Element) xmlKids.item(0);
1.309 + ImportPrefs(prefsNode, firstXmlKid);
1.310 + prefsKids = new Preferences[numXmlKids - 1];
1.311 +
1.312 + // Get involved children
1.313 + for (int i=1; i < numXmlKids; i++) {
1.314 + Element xmlKid = (Element) xmlKids.item(i);
1.315 + prefsKids[i-1] = prefsNode.node(xmlKid.getAttribute("name"));
1.316 + }
1.317 + } // unlocked the node
1.318 + // import children
1.319 + for (int i=1; i < numXmlKids; i++)
1.320 + ImportSubtree(prefsKids[i-1], (Element)xmlKids.item(i));
1.321 + }
1.322 +
1.323 + /**
1.324 + * Import the preferences described by the specified XML element
1.325 + * (a map from a preferences document) into the specified
1.326 + * preferences node.
1.327 + */
1.328 + private static void ImportPrefs(Preferences prefsNode, Element map) {
1.329 + NodeList entries = map.getChildNodes();
1.330 + for (int i=0, numEntries = entries.getLength(); i < numEntries; i++) {
1.331 + Element entry = (Element) entries.item(i);
1.332 + prefsNode.put(entry.getAttribute("key"),
1.333 + entry.getAttribute("value"));
1.334 + }
1.335 + }
1.336 +
1.337 + /**
1.338 + * Export the specified Map<String,String> to a map document on
1.339 + * the specified OutputStream as per the prefs DTD. This is used
1.340 + * as the internal (undocumented) format for FileSystemPrefs.
1.341 + *
1.342 + * @throws IOException if writing to the specified output stream
1.343 + * results in an <tt>IOException</tt>.
1.344 + */
1.345 + static void exportMap(OutputStream os, Map map) throws IOException {
1.346 + Document doc = createPrefsDoc("map");
1.347 + Element xmlMap = doc.getDocumentElement( ) ;
1.348 + xmlMap.setAttribute("MAP_XML_VERSION", MAP_XML_VERSION);
1.349 +
1.350 + for (Iterator i = map.entrySet().iterator(); i.hasNext(); ) {
1.351 + Map.Entry e = (Map.Entry) i.next();
1.352 + Element xe = (Element)
1.353 + xmlMap.appendChild(doc.createElement("entry"));
1.354 + xe.setAttribute("key", (String) e.getKey());
1.355 + xe.setAttribute("value", (String) e.getValue());
1.356 + }
1.357 +
1.358 + writeDoc(doc, os);
1.359 + }
1.360 +
1.361 + /**
1.362 + * Import Map from the specified input stream, which is assumed
1.363 + * to contain a map document as per the prefs DTD. This is used
1.364 + * as the internal (undocumented) format for FileSystemPrefs. The
1.365 + * key-value pairs specified in the XML document will be put into
1.366 + * the specified Map. (If this Map is empty, it will contain exactly
1.367 + * the key-value pairs int the XML-document when this method returns.)
1.368 + *
1.369 + * @throws IOException if reading from the specified output stream
1.370 + * results in an <tt>IOException</tt>.
1.371 + * @throws InvalidPreferencesFormatException Data on input stream does not
1.372 + * constitute a valid XML document with the mandated document type.
1.373 + */
1.374 + static void importMap(InputStream is, Map m)
1.375 + throws IOException, InvalidPreferencesFormatException
1.376 + {
1.377 + try {
1.378 + Document doc = loadPrefsDoc(is);
1.379 + Element xmlMap = doc.getDocumentElement();
1.380 + // check version
1.381 + String mapVersion = xmlMap.getAttribute("MAP_XML_VERSION");
1.382 + if (mapVersion.compareTo(MAP_XML_VERSION) > 0)
1.383 + throw new InvalidPreferencesFormatException(
1.384 + "Preferences map file format version " + mapVersion +
1.385 + " is not supported. This java installation can read" +
1.386 + " versions " + MAP_XML_VERSION + " or older. You may need" +
1.387 + " to install a newer version of JDK.");
1.388 +
1.389 + NodeList entries = xmlMap.getChildNodes();
1.390 + for (int i=0, numEntries=entries.getLength(); i<numEntries; i++) {
1.391 + Element entry = (Element) entries.item(i);
1.392 + m.put(entry.getAttribute("key"), entry.getAttribute("value"));
1.393 + }
1.394 + } catch(SAXException e) {
1.395 + throw new InvalidPreferencesFormatException(e);
1.396 + }
1.397 + }
1.398 +
1.399 + private static class Resolver implements EntityResolver {
1.400 + public InputSource resolveEntity(String pid, String sid)
1.401 + throws SAXException
1.402 + {
1.403 + if (sid.equals(PREFS_DTD_URI)) {
1.404 + InputSource is;
1.405 + is = new InputSource(new StringReader(PREFS_DTD));
1.406 + is.setSystemId(PREFS_DTD_URI);
1.407 + return is;
1.408 + }
1.409 + throw new SAXException("Invalid system identifier: " + sid);
1.410 + }
1.411 + }
1.412 +
1.413 + private static class EH implements ErrorHandler {
1.414 + public void error(SAXParseException x) throws SAXException {
1.415 + throw x;
1.416 + }
1.417 + public void fatalError(SAXParseException x) throws SAXException {
1.418 + throw x;
1.419 + }
1.420 + public void warning(SAXParseException x) throws SAXException {
1.421 + throw x;
1.422 + }
1.423 + }
1.424 +}