| /* |
| * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.util.prefs; |
| |
| import java.util.*; |
| import java.io.*; |
| import javax.xml.parsers.*; |
| import javax.xml.transform.*; |
| import javax.xml.transform.dom.*; |
| import javax.xml.transform.stream.*; |
| import org.xml.sax.*; |
| import org.w3c.dom.*; |
| |
| /** |
| * XML Support for java.util.prefs. Methods to import and export preference |
| * nodes and subtrees. |
| * |
| * @author Josh Bloch and Mark Reinhold |
| * @see Preferences |
| * @since 1.4 |
| */ |
| class XmlSupport { |
| // The required DTD URI for exported preferences |
| private static final String PREFS_DTD_URI = |
| "http://java.sun.com/dtd/preferences.dtd"; |
| |
| // The actual DTD corresponding to the URI |
| private static final String PREFS_DTD = |
| "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + |
| |
| "<!-- DTD for preferences -->" + |
| |
| "<!ELEMENT preferences (root) >" + |
| "<!ATTLIST preferences" + |
| " EXTERNAL_XML_VERSION CDATA \"0.0\" >" + |
| |
| "<!ELEMENT root (map, node*) >" + |
| "<!ATTLIST root" + |
| " type (system|user) #REQUIRED >" + |
| |
| "<!ELEMENT node (map, node*) >" + |
| "<!ATTLIST node" + |
| " name CDATA #REQUIRED >" + |
| |
| "<!ELEMENT map (entry*) >" + |
| "<!ATTLIST map" + |
| " MAP_XML_VERSION CDATA \"0.0\" >" + |
| "<!ELEMENT entry EMPTY >" + |
| "<!ATTLIST entry" + |
| " key CDATA #REQUIRED" + |
| " value CDATA #REQUIRED >" ; |
| /** |
| * Version number for the format exported preferences files. |
| */ |
| private static final String EXTERNAL_XML_VERSION = "1.0"; |
| |
| /* |
| * Version number for the internal map files. |
| */ |
| private static final String MAP_XML_VERSION = "1.0"; |
| |
| /** |
| * Export the specified preferences node and, if subTree is true, all |
| * subnodes, to the specified output stream. Preferences are exported as |
| * an XML document conforming to the definition in the Preferences spec. |
| * |
| * @throws IOException if writing to the specified output stream |
| * results in an {@code IOException}. |
| * @throws BackingStoreException if preference data cannot be read from |
| * backing store. |
| * @throws IllegalStateException if this node (or an ancestor) has been |
| * removed with the {@link Preferences#removeNode()} method. |
| */ |
| static void export(OutputStream os, final Preferences p, boolean subTree) |
| throws IOException, BackingStoreException { |
| if (((AbstractPreferences)p).isRemoved()) |
| throw new IllegalStateException("Node has been removed"); |
| Document doc = createPrefsDoc("preferences"); |
| Element preferences = doc.getDocumentElement() ; |
| preferences.setAttribute("EXTERNAL_XML_VERSION", EXTERNAL_XML_VERSION); |
| Element xmlRoot = (Element) |
| preferences.appendChild(doc.createElement("root")); |
| xmlRoot.setAttribute("type", (p.isUserNode() ? "user" : "system")); |
| |
| // Get bottom-up list of nodes from p to root, excluding root |
| List<Preferences> ancestors = new ArrayList<>(); |
| |
| for (Preferences kid = p, dad = kid.parent(); dad != null; |
| kid = dad, dad = kid.parent()) { |
| ancestors.add(kid); |
| } |
| Element e = xmlRoot; |
| for (int i=ancestors.size()-1; i >= 0; i--) { |
| e.appendChild(doc.createElement("map")); |
| e = (Element) e.appendChild(doc.createElement("node")); |
| e.setAttribute("name", ancestors.get(i).name()); |
| } |
| putPreferencesInXml(e, doc, p, subTree); |
| |
| writeDoc(doc, os); |
| } |
| |
| /** |
| * Put the preferences in the specified Preferences node into the |
| * specified XML element which is assumed to represent a node |
| * in the specified XML document which is assumed to conform to |
| * PREFS_DTD. If subTree is true, create children of the specified |
| * XML node conforming to all of the children of the specified |
| * Preferences node and recurse. |
| * |
| * @throws BackingStoreException if it is not possible to read |
| * the preferences or children out of the specified |
| * preferences node. |
| */ |
| private static void putPreferencesInXml(Element elt, Document doc, |
| Preferences prefs, boolean subTree) throws BackingStoreException |
| { |
| Preferences[] kidsCopy = null; |
| String[] kidNames = null; |
| |
| // Node is locked to export its contents and get a |
| // copy of children, then lock is released, |
| // and, if subTree = true, recursive calls are made on children |
| synchronized (((AbstractPreferences)prefs).lock) { |
| // Check if this node was concurrently removed. If yes |
| // remove it from XML Document and return. |
| if (((AbstractPreferences)prefs).isRemoved()) { |
| elt.getParentNode().removeChild(elt); |
| return; |
| } |
| // Put map in xml element |
| String[] keys = prefs.keys(); |
| Element map = (Element) elt.appendChild(doc.createElement("map")); |
| for (String key : keys) { |
| Element entry = (Element) |
| map.appendChild(doc.createElement("entry")); |
| entry.setAttribute("key", key); |
| // NEXT STATEMENT THROWS NULL PTR EXC INSTEAD OF ASSERT FAIL |
| entry.setAttribute("value", prefs.get(key, null)); |
| } |
| // Recurse if appropriate |
| if (subTree) { |
| /* Get a copy of kids while lock is held */ |
| kidNames = prefs.childrenNames(); |
| kidsCopy = new Preferences[kidNames.length]; |
| for (int i = 0; i < kidNames.length; i++) |
| kidsCopy[i] = prefs.node(kidNames[i]); |
| } |
| // release lock |
| } |
| |
| if (subTree) { |
| for (int i=0; i < kidNames.length; i++) { |
| Element xmlKid = (Element) |
| elt.appendChild(doc.createElement("node")); |
| xmlKid.setAttribute("name", kidNames[i]); |
| putPreferencesInXml(xmlKid, doc, kidsCopy[i], subTree); |
| } |
| } |
| } |
| |
| /** |
| * Import preferences from the specified input stream, which is assumed |
| * to contain an XML document in the format described in the Preferences |
| * spec. |
| * |
| * @throws IOException if reading from the specified output stream |
| * results in an {@code IOException}. |
| * @throws InvalidPreferencesFormatException Data on input stream does not |
| * constitute a valid XML document with the mandated document type. |
| */ |
| static void importPreferences(InputStream is) |
| throws IOException, InvalidPreferencesFormatException |
| { |
| try { |
| Document doc = loadPrefsDoc(is); |
| String xmlVersion = |
| doc.getDocumentElement().getAttribute("EXTERNAL_XML_VERSION"); |
| if (xmlVersion.compareTo(EXTERNAL_XML_VERSION) > 0) |
| throw new InvalidPreferencesFormatException( |
| "Exported preferences file format version " + xmlVersion + |
| " is not supported. This java installation can read" + |
| " versions " + EXTERNAL_XML_VERSION + " or older. You may need" + |
| " to install a newer version of JDK."); |
| |
| Element xmlRoot = (Element) doc.getDocumentElement(). |
| getChildNodes().item(0); |
| Preferences prefsRoot = |
| (xmlRoot.getAttribute("type").equals("user") ? |
| Preferences.userRoot() : Preferences.systemRoot()); |
| ImportSubtree(prefsRoot, xmlRoot); |
| } catch(SAXException e) { |
| throw new InvalidPreferencesFormatException(e); |
| } |
| } |
| |
| /** |
| * Create a new prefs XML document. |
| */ |
| private static Document createPrefsDoc( String qname ) { |
| try { |
| DOMImplementation di = DocumentBuilderFactory.newInstance(). |
| newDocumentBuilder().getDOMImplementation(); |
| DocumentType dt = di.createDocumentType(qname, null, PREFS_DTD_URI); |
| return di.createDocument(null, qname, dt); |
| } catch(ParserConfigurationException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| /** |
| * Load an XML document from specified input stream, which must |
| * have the requisite DTD URI. |
| */ |
| private static Document loadPrefsDoc(InputStream in) |
| throws SAXException, IOException |
| { |
| DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); |
| dbf.setIgnoringElementContentWhitespace(true); |
| dbf.setValidating(true); |
| dbf.setCoalescing(true); |
| dbf.setIgnoringComments(true); |
| try { |
| DocumentBuilder db = dbf.newDocumentBuilder(); |
| db.setEntityResolver(new Resolver()); |
| db.setErrorHandler(new EH()); |
| return db.parse(new InputSource(in)); |
| } catch (ParserConfigurationException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| /** |
| * Write XML document to the specified output stream. |
| */ |
| private static final void writeDoc(Document doc, OutputStream out) |
| throws IOException |
| { |
| try { |
| TransformerFactory tf = TransformerFactory.newInstance(); |
| try { |
| tf.setAttribute("indent-number", 2); |
| } catch (IllegalArgumentException iae) { |
| //Ignore the IAE. Should not fail the writeout even the |
| //transformer provider does not support "indent-number". |
| } |
| Transformer t = tf.newTransformer(); |
| t.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, doc.getDoctype().getSystemId()); |
| t.setOutputProperty(OutputKeys.INDENT, "yes"); |
| //Transformer resets the "indent" info if the "result" is a StreamResult with |
| //an OutputStream object embedded, creating a Writer object on top of that |
| //OutputStream object however works. |
| t.transform(new DOMSource(doc), |
| new StreamResult(new BufferedWriter(new OutputStreamWriter(out, "UTF-8")))); |
| } catch(TransformerException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| /** |
| * Recursively traverse the specified preferences node and store |
| * the described preferences into the system or current user |
| * preferences tree, as appropriate. |
| */ |
| private static void ImportSubtree(Preferences prefsNode, Element xmlNode) { |
| NodeList xmlKids = xmlNode.getChildNodes(); |
| int numXmlKids = xmlKids.getLength(); |
| /* |
| * We first lock the node, import its contents and get |
| * child nodes. Then we unlock the node and go to children |
| * Since some of the children might have been concurrently |
| * deleted we check for this. |
| */ |
| Preferences[] prefsKids; |
| /* Lock the node */ |
| synchronized (((AbstractPreferences)prefsNode).lock) { |
| //If removed, return silently |
| if (((AbstractPreferences)prefsNode).isRemoved()) |
| return; |
| |
| // Import any preferences at this node |
| Element firstXmlKid = (Element) xmlKids.item(0); |
| ImportPrefs(prefsNode, firstXmlKid); |
| prefsKids = new Preferences[numXmlKids - 1]; |
| |
| // Get involved children |
| for (int i=1; i < numXmlKids; i++) { |
| Element xmlKid = (Element) xmlKids.item(i); |
| prefsKids[i-1] = prefsNode.node(xmlKid.getAttribute("name")); |
| } |
| } // unlocked the node |
| // import children |
| for (int i=1; i < numXmlKids; i++) |
| ImportSubtree(prefsKids[i-1], (Element)xmlKids.item(i)); |
| } |
| |
| /** |
| * Import the preferences described by the specified XML element |
| * (a map from a preferences document) into the specified |
| * preferences node. |
| */ |
| private static void ImportPrefs(Preferences prefsNode, Element map) { |
| NodeList entries = map.getChildNodes(); |
| for (int i=0, numEntries = entries.getLength(); i < numEntries; i++) { |
| Element entry = (Element) entries.item(i); |
| prefsNode.put(entry.getAttribute("key"), |
| entry.getAttribute("value")); |
| } |
| } |
| |
| /** |
| * Export the specified Map<String,String> to a map document on |
| * the specified OutputStream as per the prefs DTD. This is used |
| * as the internal (undocumented) format for FileSystemPrefs. |
| * |
| * @throws IOException if writing to the specified output stream |
| * results in an {@code IOException}. |
| */ |
| static void exportMap(OutputStream os, Map<String, String> map) throws IOException { |
| Document doc = createPrefsDoc("map"); |
| Element xmlMap = doc.getDocumentElement( ) ; |
| xmlMap.setAttribute("MAP_XML_VERSION", MAP_XML_VERSION); |
| |
| for (Map.Entry<String, String> e : map.entrySet()) { |
| Element xe = (Element) |
| xmlMap.appendChild(doc.createElement("entry")); |
| xe.setAttribute("key", e.getKey()); |
| xe.setAttribute("value", e.getValue()); |
| } |
| |
| writeDoc(doc, os); |
| } |
| |
| /** |
| * Import Map from the specified input stream, which is assumed |
| * to contain a map document as per the prefs DTD. This is used |
| * as the internal (undocumented) format for FileSystemPrefs. The |
| * key-value pairs specified in the XML document will be put into |
| * the specified Map. (If this Map is empty, it will contain exactly |
| * the key-value pairs int the XML-document when this method returns.) |
| * |
| * @throws IOException if reading from the specified output stream |
| * results in an {@code IOException}. |
| * @throws InvalidPreferencesFormatException Data on input stream does not |
| * constitute a valid XML document with the mandated document type. |
| */ |
| static void importMap(InputStream is, Map<String, String> m) |
| throws IOException, InvalidPreferencesFormatException |
| { |
| try { |
| Document doc = loadPrefsDoc(is); |
| Element xmlMap = doc.getDocumentElement(); |
| // check version |
| String mapVersion = xmlMap.getAttribute("MAP_XML_VERSION"); |
| if (mapVersion.compareTo(MAP_XML_VERSION) > 0) |
| throw new InvalidPreferencesFormatException( |
| "Preferences map file format version " + mapVersion + |
| " is not supported. This java installation can read" + |
| " versions " + MAP_XML_VERSION + " or older. You may need" + |
| " to install a newer version of JDK."); |
| |
| NodeList entries = xmlMap.getChildNodes(); |
| for (int i=0, numEntries=entries.getLength(); i<numEntries; i++) { |
| Element entry = (Element) entries.item(i); |
| m.put(entry.getAttribute("key"), entry.getAttribute("value")); |
| } |
| } catch(SAXException e) { |
| throw new InvalidPreferencesFormatException(e); |
| } |
| } |
| |
| private static class Resolver implements EntityResolver { |
| public InputSource resolveEntity(String pid, String sid) |
| throws SAXException |
| { |
| if (sid.equals(PREFS_DTD_URI)) { |
| InputSource is; |
| is = new InputSource(new StringReader(PREFS_DTD)); |
| is.setSystemId(PREFS_DTD_URI); |
| return is; |
| } |
| throw new SAXException("Invalid system identifier: " + sid); |
| } |
| } |
| |
| private static class EH implements ErrorHandler { |
| public void error(SAXParseException x) throws SAXException { |
| throw x; |
| } |
| public void fatalError(SAXParseException x) throws SAXException { |
| throw x; |
| } |
| public void warning(SAXParseException x) throws SAXException { |
| throw x; |
| } |
| } |
| } |