| /* |
| * Copyright (c) 2000, 2017, 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. |
| */ |
| |
| // XMLReaderFactory.java - factory for creating a new reader. |
| // http://www.saxproject.org |
| // Written by David Megginson |
| // and by David Brownell |
| // NO WARRANTY! This class is in the Public Domain. |
| // $Id: XMLReaderFactory.java,v 1.2.2.1 2005/07/31 22:48:08 jeffsuttor Exp $ |
| |
| package org.xml.sax.helpers; |
| |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.Iterator; |
| import java.util.Objects; |
| import java.util.ServiceConfigurationError; |
| import java.util.ServiceLoader; |
| import jdk.xml.internal.SecuritySupport; |
| import org.xml.sax.SAXException; |
| import org.xml.sax.XMLReader; |
| |
| |
| /** |
| * Factory for creating an XML reader. |
| * |
| * <blockquote> |
| * <em>This module, both source code and documentation, is in the |
| * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> |
| * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a> |
| * for further information. |
| * </blockquote> |
| * |
| * <p>This class contains static methods for creating an XML reader |
| * from an explicit class name, or based on runtime defaults: |
| * |
| * <pre> |
| * try { |
| * XMLReader myReader = XMLReaderFactory.createXMLReader(); |
| * } catch (SAXException e) { |
| * System.err.println(e.getMessage()); |
| * } |
| * </pre> |
| * |
| * <p><strong>Note to Distributions bundled with parsers:</strong> |
| * You should modify the implementation of the no-arguments |
| * <em>createXMLReader</em> to handle cases where the external |
| * configuration mechanisms aren't set up. That method should do its |
| * best to return a parser when one is in the class path, even when |
| * nothing bound its class name to {@code org.xml.sax.driver} so |
| * those configuration mechanisms would see it. |
| * |
| * @since 1.4, SAX 2.0 |
| * @author David Megginson, David Brownell |
| * @version 2.0.1 (sax2r2) |
| * |
| * @deprecated It is recommended to use {@link javax.xml.parsers.SAXParserFactory} |
| * instead. |
| */ |
| @Deprecated(since="9") |
| final public class XMLReaderFactory |
| { |
| /** |
| * Private constructor. |
| * |
| * <p>This constructor prevents the class from being instantiated. |
| */ |
| private XMLReaderFactory () |
| { |
| } |
| |
| private static final String property = "org.xml.sax.driver"; |
| |
| /** |
| * Obtains a new instance of a {@link org.xml.sax.XMLReader}. |
| * This method uses the following ordered lookup procedure to find and load |
| * the {@link org.xml.sax.XMLReader} implementation class: |
| * <ol> |
| * <li>If the system property {@code org.xml.sax.driver} |
| * has a value, that is used as an XMLReader class name. </li> |
| * <li> |
| * Use the service-provider loading facility, defined by the |
| * {@link java.util.ServiceLoader} class, to attempt to locate and load an |
| * implementation of the service {@link org.xml.sax.XMLReader} by using the |
| * {@linkplain java.lang.Thread#getContextClassLoader() current thread's context class loader}. |
| * If the context class loader is null, the |
| * {@linkplain ClassLoader#getSystemClassLoader() system class loader} will |
| * be used. |
| * </li> |
| * <li> |
| * Deprecated. Look for a class name in the {@code META-INF/services/org.xml.sax.driver} |
| * file in a jar file available to the runtime.</li> |
| * <li> |
| * <p> |
| * Otherwise, the system-default implementation is returned. |
| * </li> |
| * </ol> |
| * |
| * @apiNote |
| * The process that looks for a class name in the |
| * {@code META-INF/services/org.xml.sax.driver} file in a jar file does not |
| * conform to the specification of the service-provider loading facility |
| * as defined in {@link java.util.ServiceLoader} and therefore does not |
| * support modularization. It is deprecated as of Java SE 9 and subject to |
| * removal in a future release. |
| * |
| * @return a new XMLReader. |
| * @exception org.xml.sax.SAXException If no default XMLReader class |
| * can be identified and instantiated. |
| * @see #createXMLReader(java.lang.String) |
| */ |
| public static XMLReader createXMLReader () |
| throws SAXException |
| { |
| String className = null; |
| ClassLoader cl = SecuritySupport.getClassLoader(); |
| |
| // 1. try the JVM-instance-wide system property |
| try { |
| className = SecuritySupport.getSystemProperty(property); |
| } |
| catch (RuntimeException e) { /* continue searching */ } |
| |
| // 2. try the ServiceLoader |
| if (className == null) { |
| final XMLReader provider = findServiceProvider(XMLReader.class, cl); |
| if (provider != null) { |
| return provider; |
| } |
| } |
| |
| // 3. try META-INF/services/org.xml.sax.driver. This old process allows |
| // legacy providers to be found |
| if (className == null) { |
| className = jarLookup(cl); |
| } |
| |
| // 4. Distro-specific fallback |
| if (className == null) { |
| return new com.sun.org.apache.xerces.internal.parsers.SAXParser(); |
| } |
| |
| return loadClass (cl, className); |
| } |
| |
| |
| /** |
| * Attempt to create an XML reader from a class name. |
| * |
| * <p>Given a class name, this method attempts to load |
| * and instantiate the class as an XML reader. |
| * |
| * <p>Note that this method will not be usable in environments where |
| * the caller (perhaps an applet) is not permitted to load classes |
| * dynamically. |
| * |
| * @return A new XML reader. |
| * @exception org.xml.sax.SAXException If the class cannot be |
| * loaded, instantiated, and cast to XMLReader. |
| * @see #createXMLReader() |
| */ |
| public static XMLReader createXMLReader (String className) |
| throws SAXException |
| { |
| return loadClass (SecuritySupport.getClassLoader(), className); |
| } |
| |
| private static XMLReader loadClass (ClassLoader loader, String className) |
| throws SAXException |
| { |
| try { |
| return NewInstance.newInstance (XMLReader.class, loader, className); |
| } catch (ClassNotFoundException e1) { |
| throw new SAXException("SAX2 driver class " + className + |
| " not found", e1); |
| } catch (IllegalAccessException e2) { |
| throw new SAXException("SAX2 driver class " + className + |
| " found but cannot be loaded", e2); |
| } catch (InstantiationException e3) { |
| throw new SAXException("SAX2 driver class " + className + |
| " loaded but cannot be instantiated (no empty public constructor?)", |
| e3); |
| } catch (ClassCastException e4) { |
| throw new SAXException("SAX2 driver class " + className + |
| " does not implement XMLReader", e4); |
| } |
| } |
| |
| /** |
| * Locates a provider by directly reading the jar service file. |
| * @param loader the ClassLoader to be used to read the service file |
| * @return the name of the provider, or null if nothing is found |
| */ |
| private static String jarLookup(final ClassLoader loader) { |
| final ClassLoader cl = Objects.requireNonNull(loader); |
| String clsFromJar = null; |
| String service = "META-INF/services/" + property; |
| InputStream in; |
| BufferedReader reader; |
| |
| try { |
| in = SecuritySupport.getResourceAsStream(cl, service); |
| |
| // If no provider found then try the current ClassLoader |
| if (in == null) { |
| in = SecuritySupport.getResourceAsStream(null, service); |
| } |
| |
| if (in != null) { |
| reader = new BufferedReader (new InputStreamReader (in, "UTF8")); |
| clsFromJar = reader.readLine (); |
| in.close (); |
| } |
| } catch (IOException e) { |
| } |
| return clsFromJar; |
| } |
| |
| /* |
| * Try to find provider using the ServiceLoader API |
| * |
| * @param type Base class / Service interface of the factory to find. |
| * |
| * @return instance of provider class if found or null |
| */ |
| private static <T> T findServiceProvider(final Class<T> type, final ClassLoader loader) |
| throws SAXException { |
| ClassLoader cl = Objects.requireNonNull(loader); |
| try { |
| return AccessController.doPrivileged((PrivilegedAction<T>) () -> { |
| final ServiceLoader<T> serviceLoader; |
| serviceLoader = ServiceLoader.load(type, cl); |
| final Iterator<T> iterator = serviceLoader.iterator(); |
| if (iterator.hasNext()) { |
| return iterator.next(); |
| } else { |
| return null; |
| } |
| }); |
| } catch(ServiceConfigurationError e) { |
| final RuntimeException x = new RuntimeException( |
| "Provider for " + type + " cannot be created", e); |
| throw new SAXException("Provider for " + type + " cannot be created", x); |
| |
| } |
| } |
| |
| } |
