jtulach@1263: /*
jtulach@1263:  * Copyright 2002-2006 Sun Microsystems, Inc.  All Rights Reserved.
jtulach@1263:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jtulach@1263:  *
jtulach@1263:  * This code is free software; you can redistribute it and/or modify it
jtulach@1263:  * under the terms of the GNU General Public License version 2 only, as
jtulach@1263:  * published by the Free Software Foundation.  Sun designates this
jtulach@1263:  * particular file as subject to the "Classpath" exception as provided
jtulach@1263:  * by Sun in the LICENSE file that accompanied this code.
jtulach@1263:  *
jtulach@1263:  * This code is distributed in the hope that it will be useful, but WITHOUT
jtulach@1263:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jtulach@1263:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jtulach@1263:  * version 2 for more details (a copy is included in the LICENSE file that
jtulach@1263:  * accompanied this code).
jtulach@1263:  *
jtulach@1263:  * You should have received a copy of the GNU General Public License version
jtulach@1263:  * 2 along with this work; if not, write to the Free Software Foundation,
jtulach@1263:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jtulach@1263:  *
jtulach@1263:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
jtulach@1263:  * CA 95054 USA or visit www.sun.com if you need additional information or
jtulach@1263:  * have any questions.
jtulach@1263:  */
jtulach@1263: 
jtulach@1263: package sun.util.xml;
jtulach@1263: 
jtulach@1263: import java.util.*;
jtulach@1263: import java.util.prefs.*;
jtulach@1263: import java.io.*;
jtulach@1263: 
jtulach@1263: /**
jtulach@1263:  * Simplified XML Support for java.util.prefs. Methods to import and export preference
jtulach@1263:  * nodes and subtrees.
jtulach@1263:  *
jtulach@1263:  * @author  Jaroslav Tulach
jtulach@1263:  * @since   1.7
jtulach@1263:  */
jtulach@1263: public class DefaultPrefsXmlSupport extends sun.util.xml.PrefsXmlSupport {
jtulach@1263:     public void export(OutputStream os, final Preferences p, boolean subTree)
jtulach@1263:         throws IOException, BackingStoreException {
jtulach@1263:         if (isRemoved(p))
jtulach@1263:             throw new IllegalStateException("Node has been removed");
jtulach@1263:         PrintWriter w = new PrintWriter(new OutputStreamWriter(os, "UTF-8"));
jtulach@1263:         w.println("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>");
jtulach@1263:         w.println("<!DOCTYPE preferences SYSTEM \"http://java.sun.com/dtd/preferences.dtd\">");
jtulach@1263:         w.println("<preferences EXTERNAL_XML_VERSION=\"1.0\">");
jtulach@1263:         w.print("  <root type=\"");
jtulach@1263:         w.print(p.isUserNode() ? "user" : "system");
jtulach@1263:         w.println("\">");
jtulach@1263:         LinkedList<Preferences> ancestors = new LinkedList<Preferences>();
jtulach@1263:         for (Preferences kid = p, dad = kid.parent(); dad != null;
jtulach@1263:                 kid = dad, dad = kid.parent()) {
jtulach@1263:             ancestors.addFirst(kid);
jtulach@1263:         }
jtulach@1263:         String indent = "  ";
jtulach@1263:         for (Preferences pref : ancestors) {
jtulach@1263:             indent = "  " + indent;
jtulach@1263:             w.print(indent); w.println("<map/>");
jtulach@1263:             w.print(indent); w.print("<node name=\""); w.print(pref.name()); w.println("\">");
jtulach@1263:         }
jtulach@1263: 
jtulach@1263:         putPreferencesInXml(w, indent + "  ", p, subTree);
jtulach@1263:         for (Preferences pref : ancestors) {
jtulach@1263:             w.print(indent); w.println("</node>");
jtulach@1263:             indent = indent.substring(2);
jtulach@1263:         }
jtulach@1263: 
jtulach@1263:         w.println("  </root>");
jtulach@1263:         w.println("</preferences>");
jtulach@1263:         w.flush();
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     private static void putPreferencesInXml(
jtulach@1263:         PrintWriter w, String indent, Preferences prefs, boolean subTree
jtulach@1263:     ) throws BackingStoreException {
jtulach@1263:         Preferences[] kidsCopy = null;
jtulach@1263:         String[] kidNames = null;
jtulach@1263: 
jtulach@1263:         // Node is locked to export its contents and get a
jtulach@1263:         // copy of children, then lock is released,
jtulach@1263:         // and, if subTree = true, recursive calls are made on children
jtulach@1263:         synchronized (lock(prefs)) {
jtulach@1263:             // Check if this node was concurrently removed. If yes
jtulach@1263:             // don't print it
jtulach@1263:             if (isRemoved(prefs)) {
jtulach@1263:                 return;
jtulach@1263:             }
jtulach@1263:             // Put map in xml element
jtulach@1263:             String[] keys = prefs.keys();
jtulach@1263:             if (keys.length == 0) {
jtulach@1263:                 w.print(indent); w.println("<map/>");
jtulach@1263:             } else {
jtulach@1263:                 w.print(indent); w.println("<map>");
jtulach@1263:                 for (int i=0; i<keys.length; i++) {
jtulach@1263:                     w.print(indent); w.print("  <entry key=\"");
jtulach@1263:                     w.print(keys[i]);
jtulach@1263:                     w.print("\" value=\"");
jtulach@1263:                     w.print(prefs.get(keys[i], null));
jtulach@1263:                     w.println("\"/>");
jtulach@1263:                 }
jtulach@1263:                 w.print(indent); w.println("</map>");
jtulach@1263:             }
jtulach@1263:             // Recurse if appropriate
jtulach@1263:             if (subTree) {
jtulach@1263:                 /* Get a copy of kids while lock is held */
jtulach@1263:                 kidNames = prefs.childrenNames();
jtulach@1263:                 kidsCopy = new Preferences[kidNames.length];
jtulach@1263:                 for (int i = 0; i <  kidNames.length; i++)
jtulach@1263:                     kidsCopy[i] = prefs.node(kidNames[i]);
jtulach@1263:             }
jtulach@1263:             // release lock
jtulach@1263:         }
jtulach@1263: 
jtulach@1263:         if (subTree) {
jtulach@1263:             for (int i=0; i < kidNames.length; i++) {
jtulach@1263:                 w.print(indent); w.print("<node name=\"");
jtulach@1263:                 w.print(kidNames[i]);
jtulach@1263:                 w.println("\">");
jtulach@1263:                 putPreferencesInXml(w, "  " + indent, kidsCopy[i], subTree);
jtulach@1263:                 w.print(indent); w.println("</node>");
jtulach@1263:             }
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Import preferences from the specified input stream, which is assumed
jtulach@1263:      * to contain an XML document in the format described in the Preferences
jtulach@1263:      * spec.
jtulach@1263:      *
jtulach@1263:      * @throws IOException if reading from the specified output stream
jtulach@1263:      *         results in an <tt>IOException</tt>.
jtulach@1263:      * @throws InvalidPreferencesFormatException Data on input stream does not
jtulach@1263:      *         constitute a valid XML document with the mandated document type.
jtulach@1263:      */
jtulach@1263:     public void importPreferences(InputStream is)
jtulach@1263:         throws IOException, InvalidPreferencesFormatException
jtulach@1263:     {
jtulach@1263:         /*
jtulach@1263:         try {
jtulach@1263:             Document doc = loadPrefsDoc(is);
jtulach@1263:             String xmlVersion =
jtulach@1263:                 doc.getDocumentElement().getAttribute("EXTERNAL_XML_VERSION");
jtulach@1263:             if (xmlVersion.compareTo(EXTERNAL_XML_VERSION) > 0)
jtulach@1263:                 throw new InvalidPreferencesFormatException(
jtulach@1263:                 "Exported preferences file format version " + xmlVersion +
jtulach@1263:                 " is not supported. This java installation can read" +
jtulach@1263:                 " versions " + EXTERNAL_XML_VERSION + " or older. You may need" +
jtulach@1263:                 " to install a newer version of JDK.");
jtulach@1263: 
jtulach@1263:             Element xmlRoot = (Element) doc.getDocumentElement().
jtulach@1263:                                                getChildNodes().item(0);
jtulach@1263:             Preferences prefsRoot =
jtulach@1263:                 (xmlRoot.getAttribute("type").equals("user") ?
jtulach@1263:                             Preferences.userRoot() : Preferences.systemRoot());
jtulach@1263:             ImportSubtree(prefsRoot, xmlRoot);
jtulach@1263:         } catch(SAXException e) {
jtulach@1263:             throw new InvalidPreferencesFormatException(e);
jtulach@1263:         }
jtulach@1263:          */
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Create a new prefs XML document.
jtulach@1263:      *
jtulach@1263:     private static Document createPrefsDoc( String qname ) {
jtulach@1263:         try {
jtulach@1263:             DOMImplementation di = DocumentBuilderFactory.newInstance().
jtulach@1263:                 newDocumentBuilder().getDOMImplementation();
jtulach@1263:             DocumentType dt = di.createDocumentType(qname, null, PREFS_DTD_URI);
jtulach@1263:             return di.createDocument(null, qname, dt);
jtulach@1263:         } catch(ParserConfigurationException e) {
jtulach@1263:             throw new AssertionError(e);
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Load an XML document from specified input stream, which must
jtulach@1263:      * have the requisite DTD URI.
jtulach@1263:      *
jtulach@1263:     private static Document loadPrefsDoc(InputStream in)
jtulach@1263:         throws SAXException, IOException
jtulach@1263:     {
jtulach@1263:         DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
jtulach@1263:         dbf.setIgnoringElementContentWhitespace(true);
jtulach@1263:         dbf.setValidating(true);
jtulach@1263:         dbf.setCoalescing(true);
jtulach@1263:         dbf.setIgnoringComments(true);
jtulach@1263:         try {
jtulach@1263:             DocumentBuilder db = dbf.newDocumentBuilder();
jtulach@1263:             db.setEntityResolver(new Resolver());
jtulach@1263:             db.setErrorHandler(new EH());
jtulach@1263:             return db.parse(new InputSource(in));
jtulach@1263:         } catch (ParserConfigurationException e) {
jtulach@1263:             throw new AssertionError(e);
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Write XML document to the specified output stream.
jtulach@1263:      *
jtulach@1263:     private static final void writeDoc(Document doc, OutputStream out)
jtulach@1263:         throws IOException
jtulach@1263:     {
jtulach@1263:         try {
jtulach@1263:             TransformerFactory tf = TransformerFactory.newInstance();
jtulach@1263:             try {
jtulach@1263:                 tf.setAttribute("indent-number", new Integer(2));
jtulach@1263:             } catch (IllegalArgumentException iae) {
jtulach@1263:                 //Ignore the IAE. Should not fail the writeout even the
jtulach@1263:                 //transformer provider does not support "indent-number".
jtulach@1263:             }
jtulach@1263:             Transformer t = tf.newTransformer();
jtulach@1263:             t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId());
jtulach@1263:             t.setOutputProperty(OutputKeys.INDENT, "yes");
jtulach@1263:             //Transformer resets the "indent" info if the "result" is a StreamResult with
jtulach@1263:             //an OutputStream object embedded, creating a Writer object on top of that
jtulach@1263:             //OutputStream object however works.
jtulach@1263:             t.transform(new DOMSource(doc),
jtulach@1263:                         new StreamResult(new BufferedWriter(new OutputStreamWriter(out, "UTF-8"))));
jtulach@1263:         } catch(TransformerException e) {
jtulach@1263:             throw new AssertionError(e);
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Recursively traverse the specified preferences node and store
jtulach@1263:      * the described preferences into the system or current user
jtulach@1263:      * preferences tree, as appropriate.
jtulach@1263:      *
jtulach@1263:     private static void ImportSubtree(Preferences prefsNode, Element xmlNode) {
jtulach@1263:         NodeList xmlKids = xmlNode.getChildNodes();
jtulach@1263:         int numXmlKids = xmlKids.getLength();
jtulach@1263:         /*
jtulach@1263:          * We first lock the node, import its contents and get
jtulach@1263:          * child nodes. Then we unlock the node and go to children
jtulach@1263:          * Since some of the children might have been concurrently
jtulach@1263:          * deleted we check for this.
jtulach@1263:          * /
jtulach@1263:         Preferences[] prefsKids;
jtulach@1263:         /* Lock the node * /
jtulach@1263:         synchronized (lock(prefsNode)) {
jtulach@1263:             //If removed, return silently
jtulach@1263:             if (isRemoved(prefsNode))
jtulach@1263:                 return;
jtulach@1263: 
jtulach@1263:             // Import any preferences at this node
jtulach@1263:             Element firstXmlKid = (Element) xmlKids.item(0);
jtulach@1263:             ImportPrefs(prefsNode, firstXmlKid);
jtulach@1263:             prefsKids = new Preferences[numXmlKids - 1];
jtulach@1263: 
jtulach@1263:             // Get involved children
jtulach@1263:             for (int i=1; i < numXmlKids; i++) {
jtulach@1263:                 Element xmlKid = (Element) xmlKids.item(i);
jtulach@1263:                 prefsKids[i-1] = prefsNode.node(xmlKid.getAttribute("name"));
jtulach@1263:             }
jtulach@1263:         } // unlocked the node
jtulach@1263:         // import children
jtulach@1263:         for (int i=1; i < numXmlKids; i++)
jtulach@1263:             ImportSubtree(prefsKids[i-1], (Element)xmlKids.item(i));
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Import the preferences described by the specified XML element
jtulach@1263:      * (a map from a preferences document) into the specified
jtulach@1263:      * preferences node.
jtulach@1263:      * /
jtulach@1263:     private static void ImportPrefs(Preferences prefsNode, Element map) {
jtulach@1263:         NodeList entries = map.getChildNodes();
jtulach@1263:         for (int i=0, numEntries = entries.getLength(); i < numEntries; i++) {
jtulach@1263:             Element entry = (Element) entries.item(i);
jtulach@1263:             prefsNode.put(entry.getAttribute("key"),
jtulach@1263:                           entry.getAttribute("value"));
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Export the specified Map<String,String> to a map document on
jtulach@1263:      * the specified OutputStream as per the prefs DTD.  This is used
jtulach@1263:      * as the internal (undocumented) format for FileSystemPrefs.
jtulach@1263:      *
jtulach@1263:      * @throws IOException if writing to the specified output stream
jtulach@1263:      *         results in an <tt>IOException</tt>.
jtulach@1263:      */
jtulach@1263:     public void exportMap(OutputStream os, Map map) throws IOException {
jtulach@1263:         /*
jtulach@1263:         Document doc = createPrefsDoc("map");
jtulach@1263:         Element xmlMap = doc.getDocumentElement( ) ;
jtulach@1263:         xmlMap.setAttribute("MAP_XML_VERSION", MAP_XML_VERSION);
jtulach@1263: 
jtulach@1263:         for (Iterator i = map.entrySet().iterator(); i.hasNext(); ) {
jtulach@1263:             Map.Entry e = (Map.Entry) i.next();
jtulach@1263:             Element xe = (Element)
jtulach@1263:                 xmlMap.appendChild(doc.createElement("entry"));
jtulach@1263:             xe.setAttribute("key",   (String) e.getKey());
jtulach@1263:             xe.setAttribute("value", (String) e.getValue());
jtulach@1263:         }
jtulach@1263: 
jtulach@1263:         writeDoc(doc, os);
jtulach@1263:          */
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     /**
jtulach@1263:      * Import Map from the specified input stream, which is assumed
jtulach@1263:      * to contain a map document as per the prefs DTD.  This is used
jtulach@1263:      * as the internal (undocumented) format for FileSystemPrefs.  The
jtulach@1263:      * key-value pairs specified in the XML document will be put into
jtulach@1263:      * the specified Map.  (If this Map is empty, it will contain exactly
jtulach@1263:      * the key-value pairs int the XML-document when this method returns.)
jtulach@1263:      *
jtulach@1263:      * @throws IOException if reading from the specified output stream
jtulach@1263:      *         results in an <tt>IOException</tt>.
jtulach@1263:      * @throws InvalidPreferencesFormatException Data on input stream does not
jtulach@1263:      *         constitute a valid XML document with the mandated document type.
jtulach@1263:      */
jtulach@1263:     public void importMap(InputStream is, Map m)
jtulach@1263:         throws IOException, InvalidPreferencesFormatException
jtulach@1263:     {
jtulach@1263:         /*
jtulach@1263:         try {
jtulach@1263:             Document doc = loadPrefsDoc(is);
jtulach@1263:             Element xmlMap = doc.getDocumentElement();
jtulach@1263:             // check version
jtulach@1263:             String mapVersion = xmlMap.getAttribute("MAP_XML_VERSION");
jtulach@1263:             if (mapVersion.compareTo(MAP_XML_VERSION) > 0)
jtulach@1263:                 throw new InvalidPreferencesFormatException(
jtulach@1263:                 "Preferences map file format version " + mapVersion +
jtulach@1263:                 " is not supported. This java installation can read" +
jtulach@1263:                 " versions " + MAP_XML_VERSION + " or older. You may need" +
jtulach@1263:                 " to install a newer version of JDK.");
jtulach@1263: 
jtulach@1263:             NodeList entries = xmlMap.getChildNodes();
jtulach@1263:             for (int i=0, numEntries=entries.getLength(); i<numEntries; i++) {
jtulach@1263:                 Element entry = (Element) entries.item(i);
jtulach@1263:                 m.put(entry.getAttribute("key"), entry.getAttribute("value"));
jtulach@1263:             }
jtulach@1263:         } catch(SAXException e) {
jtulach@1263:             throw new InvalidPreferencesFormatException(e);
jtulach@1263:         }
jtulach@1263:          */
jtulach@1263:     }
jtulach@1263: /*
jtulach@1263:     private static class Resolver implements EntityResolver {
jtulach@1263:         public InputSource resolveEntity(String pid, String sid)
jtulach@1263:             throws SAXException
jtulach@1263:         {
jtulach@1263:             if (sid.equals(PREFS_DTD_URI)) {
jtulach@1263:                 InputSource is;
jtulach@1263:                 is = new InputSource(new StringReader(PREFS_DTD));
jtulach@1263:                 is.setSystemId(PREFS_DTD_URI);
jtulach@1263:                 return is;
jtulach@1263:             }
jtulach@1263:             throw new SAXException("Invalid system identifier: " + sid);
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     private static class EH implements ErrorHandler {
jtulach@1263:         public void error(SAXParseException x) throws SAXException {
jtulach@1263:             throw x;
jtulach@1263:         }
jtulach@1263:         public void fatalError(SAXParseException x) throws SAXException {
jtulach@1263:             throw x;
jtulach@1263:         }
jtulach@1263:         public void warning(SAXParseException x) throws SAXException {
jtulach@1263:             throw x;
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: */
jtulach@1263:     private static boolean isRemoved(Preferences p) {
jtulach@1263:         try {
jtulach@1263:             p.parent(); // throws IllegalStateException if removed;
jtulach@1263:             return false;
jtulach@1263:         } catch (IllegalStateException ex) {
jtulach@1263:             return true;
jtulach@1263:         }
jtulach@1263:     }
jtulach@1263: 
jtulach@1263:     private static Object lock(Preferences p) {
jtulach@1263:         /** JST-XXX: Needs reflection or accessor:
jtulach@1263:          * http://wiki.apidesign.org/wiki/FriendPackages
jtulach@1263:         return ((AbstractPreferences)prefs).lock;
jtulach@1263:          */
jtulach@1263:         return p;
jtulach@1263:     }
jtulach@1263: }