| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| // $Id: SchemaFactoryFinder.java 727367 2008-12-17 13:05:26Z mrglavas $ |
| |
| package javax.xml.validation; |
| |
| import java.io.BufferedReader; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.net.URL; |
| import java.util.Collections; |
| import java.util.Enumeration; |
| import java.util.Iterator; |
| import java.util.Properties; |
| import javax.xml.XMLConstants; |
| import libcore.io.IoUtils; |
| |
| /** |
| * Implementation of {@link SchemaFactory#newInstance(String)}. |
| * |
| * @author <a href="[email protected]">Kohsuke Kawaguchi</a> |
| * @version $Revision: 727367 $, $Date: 2008-12-17 05:05:26 -0800 (Wed, 17 Dec 2008) $ |
| * @since 1.5 |
| */ |
| final class SchemaFactoryFinder { |
| |
| /** XML Schema language identifiers. */ |
| private static final String W3C_XML_SCHEMA10_NS_URI = "http://www.w3.org/XML/XMLSchema/v1.0"; |
| private static final String W3C_XML_SCHEMA11_NS_URI = "http://www.w3.org/XML/XMLSchema/v1.1"; |
| |
| /** debug support code. */ |
| private static boolean debug = false; |
| |
| /** |
| * <p>Cache properties for performance. Use a static class to avoid double-checked |
| * locking.</p> |
| */ |
| private static class CacheHolder { |
| |
| private static Properties cacheProps = new Properties(); |
| |
| static { |
| String javah = System.getProperty("java.home"); |
| String configFile = javah + File.separator + "lib" + File.separator + "jaxp.properties"; |
| File f = new File(configFile); |
| if (f.exists()) { |
| if (debug) debugPrintln("Read properties file " + f); |
| try (FileInputStream inputStream = new FileInputStream(f)) { |
| cacheProps.load(inputStream); |
| } catch (Exception ex) { |
| if (debug) { |
| ex.printStackTrace(); |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Default columns per line. |
| */ |
| private static final int DEFAULT_LINE_LENGTH = 80; |
| |
| static { |
| String val = System.getProperty("jaxp.debug"); |
| // Allow simply setting the prop to turn on debug |
| debug = val != null && (! "false".equals(val)); |
| } |
| |
| /** |
| * <p>Conditional debug printing.</p> |
| * |
| * @param msg to print |
| */ |
| private static void debugPrintln(String msg) { |
| if (debug) { |
| System.err.println("JAXP: " + msg); |
| } |
| } |
| |
| /** |
| * <p><code>ClassLoader</code> to use to find <code>SchemaFactory</code>.</p> |
| */ |
| private final ClassLoader classLoader; |
| |
| /** |
| * <p>Constructor that specifies <code>ClassLoader</code> to use |
| * to find <code>SchemaFactory</code>.</p> |
| * |
| * @param loader |
| * to be used to load resource, {@link SchemaFactory}, and |
| * {@link SchemaFactoryLoader} implementations during |
| * the resolution process. |
| * If this parameter is null, the default system class loader |
| * will be used. |
| */ |
| public SchemaFactoryFinder(ClassLoader loader) { |
| this.classLoader = loader; |
| if( debug ) { |
| debugDisplayClassLoader(); |
| } |
| } |
| |
| private void debugDisplayClassLoader() { |
| if (classLoader == Thread.currentThread().getContextClassLoader()) { |
| debugPrintln("using thread context class loader ("+classLoader+") for search"); |
| return; |
| } |
| |
| if (classLoader == ClassLoader.getSystemClassLoader()) { |
| debugPrintln("using system class loader ("+classLoader+") for search"); |
| return; |
| } |
| |
| debugPrintln("using class loader (" + classLoader + ") for search"); |
| } |
| |
| /** |
| * <p>Creates a new {@link SchemaFactory} object for the specified |
| * schema language.</p> |
| * |
| * @param schemaLanguage |
| * See {@link SchemaFactory Schema Language} table in <code>SchemaFactory</code> |
| * for the list of available schema languages. |
| * |
| * @return <code>null</code> if the callee fails to create one. |
| * |
| * @throws NullPointerException |
| * If the <tt>schemaLanguage</tt> parameter is null. |
| */ |
| public SchemaFactory newFactory(String schemaLanguage) { |
| if (schemaLanguage == null) { |
| throw new NullPointerException("schemaLanguage == null"); |
| } |
| SchemaFactory f = _newFactory(schemaLanguage); |
| if (debug) { |
| if (f != null) { |
| debugPrintln("factory '" + f.getClass().getName() + "' was found for " + schemaLanguage); |
| } else { |
| debugPrintln("unable to find a factory for " + schemaLanguage); |
| } |
| } |
| return f; |
| } |
| |
| /** |
| * <p>Lookup a <code>SchemaFactory</code> for the given <code>schemaLanguage</code>.</p> |
| * |
| * @param schemaLanguage Schema language to lookup <code>SchemaFactory</code> for. |
| * |
| * @return <code>SchemaFactory</code> for the given <code>schemaLanguage</code>. |
| */ |
| private SchemaFactory _newFactory(String schemaLanguage) { |
| SchemaFactory sf; |
| String propertyName = SERVICE_CLASS.getName() + ":" + schemaLanguage; |
| |
| // system property look up |
| try { |
| if (debug) debugPrintln("Looking up system property '"+propertyName+"'" ); |
| String r = System.getProperty(propertyName); |
| if (r != null && r.length() > 0) { |
| if (debug) debugPrintln("The value is '"+r+"'"); |
| sf = createInstance(r); |
| if(sf!=null) return sf; |
| } |
| else if (debug) { |
| debugPrintln("The property is undefined."); |
| } |
| } |
| // The VM ran out of memory or there was some other serious problem. Re-throw. |
| catch (VirtualMachineError vme) { |
| throw vme; |
| } |
| // ThreadDeath should always be re-thrown |
| catch (ThreadDeath td) { |
| throw td; |
| } |
| catch (Throwable t) { |
| if( debug ) { |
| debugPrintln("failed to look up system property '"+propertyName+"'" ); |
| t.printStackTrace(); |
| } |
| } |
| |
| // try to read from $java.home/lib/jaxp.properties |
| try { |
| String factoryClassName = CacheHolder.cacheProps.getProperty(propertyName); |
| if (debug) debugPrintln("found " + factoryClassName + " in $java.home/jaxp.properties"); |
| |
| if (factoryClassName != null) { |
| sf = createInstance(factoryClassName); |
| if(sf != null){ |
| return sf; |
| } |
| } |
| } catch (Exception ex) { |
| if (debug) { |
| ex.printStackTrace(); |
| } |
| } |
| |
| // try META-INF/services files |
| for (URL resource : createServiceFileIterator()) { |
| if (debug) debugPrintln("looking into " + resource); |
| try { |
| sf = loadFromServicesFile(schemaLanguage,resource.toExternalForm(), |
| resource.openStream()); |
| if(sf!=null) return sf; |
| } catch(IOException e) { |
| if( debug ) { |
| debugPrintln("failed to read "+resource); |
| e.printStackTrace(); |
| } |
| } |
| } |
| |
| // platform defaults |
| if (schemaLanguage.equals(XMLConstants.W3C_XML_SCHEMA_NS_URI) || schemaLanguage.equals(W3C_XML_SCHEMA10_NS_URI)) { |
| if (debug) debugPrintln("attempting to use the platform default XML Schema 1.0 validator"); |
| return createInstance("org.apache.xerces.jaxp.validation.XMLSchemaFactory"); |
| } |
| else if (schemaLanguage.equals(W3C_XML_SCHEMA11_NS_URI)) { |
| if (debug) debugPrintln("attempting to use the platform default XML Schema 1.1 validator"); |
| return createInstance("org.apache.xerces.jaxp.validation.XMLSchema11Factory"); |
| } |
| |
| if (debug) debugPrintln("all things were tried, but none was found. bailing out."); |
| return null; |
| } |
| |
| /** |
| * <p>Creates an instance of the specified and returns it.</p> |
| * |
| * @param className |
| * fully qualified class name to be instantiated. |
| * |
| * @return null |
| * if it fails. Error messages will be printed by this method. |
| */ |
| SchemaFactory createInstance( String className ) { |
| try { |
| if (debug) debugPrintln("instantiating "+className); |
| Class clazz; |
| if( classLoader!=null ) |
| clazz = classLoader.loadClass(className); |
| else |
| clazz = Class.forName(className); |
| if(debug) debugPrintln("loaded it from "+which(clazz)); |
| Object o = clazz.newInstance(); |
| |
| if( o instanceof SchemaFactory ) |
| return (SchemaFactory)o; |
| |
| if (debug) debugPrintln(className+" is not assignable to "+SERVICE_CLASS.getName()); |
| } |
| // The VM ran out of memory or there was some other serious problem. Re-throw. |
| catch (VirtualMachineError vme) { |
| throw vme; |
| } |
| // ThreadDeath should always be re-thrown |
| catch (ThreadDeath td) { |
| throw td; |
| } |
| catch (Throwable t) { |
| debugPrintln("failed to instantiate "+className); |
| if(debug) t.printStackTrace(); |
| } |
| return null; |
| } |
| |
| /** |
| * Returns an {@link Iterator} that enumerates all |
| * the META-INF/services files that we care. |
| */ |
| private Iterable<URL> createServiceFileIterator() { |
| if (classLoader == null) { |
| ClassLoader classLoader = SchemaFactoryFinder.class.getClassLoader(); |
| return Collections.singleton(classLoader.getResource(SERVICE_ID)); |
| } else { |
| try { |
| Enumeration<URL> e = classLoader.getResources(SERVICE_ID); |
| if (debug && !e.hasMoreElements()) { |
| debugPrintln("no "+SERVICE_ID+" file was found"); |
| } |
| |
| // wrap it into an Iterator. |
| return Collections.list(e); |
| } catch (IOException e) { |
| if (debug) { |
| debugPrintln("failed to enumerate resources "+SERVICE_ID); |
| e.printStackTrace(); |
| } |
| return Collections.emptySet(); |
| } |
| } |
| } |
| |
| /** Searches for a SchemaFactory for a given schema language in a META-INF/services file. */ |
| private SchemaFactory loadFromServicesFile(String schemaLanguage, String resourceName, InputStream in) { |
| |
| if (debug) debugPrintln("Reading "+resourceName ); |
| |
| // Read the service provider name in UTF-8 as specified in |
| // the jar spec. Unfortunately this fails in Microsoft |
| // VJ++, which does not implement the UTF-8 |
| // encoding. Theoretically, we should simply let it fail in |
| // that case, since the JVM is obviously broken if it |
| // doesn't support such a basic standard. But since there |
| // are still some users attempting to use VJ++ for |
| // development, we have dropped in a fallback which makes a |
| // second attempt using the platform's default encoding. In |
| // VJ++ this is apparently ASCII, which is a subset of |
| // UTF-8... and since the strings we'll be reading here are |
| // also primarily limited to the 7-bit ASCII range (at |
| // least, in English versions), this should work well |
| // enough to keep us on the air until we're ready to |
| // officially decommit from VJ++. [Edited comment from |
| // jkesselm] |
| BufferedReader rd; |
| try { |
| rd = new BufferedReader(new InputStreamReader(in, "UTF-8"), DEFAULT_LINE_LENGTH); |
| } catch (java.io.UnsupportedEncodingException e) { |
| rd = new BufferedReader(new InputStreamReader(in), DEFAULT_LINE_LENGTH); |
| } |
| |
| String factoryClassName = null; |
| SchemaFactory resultFactory = null; |
| // See spec for provider-configuration files: http://java.sun.com/j2se/1.5.0/docs/guide/jar/jar.html#Provider%20Configuration%20File |
| while (true) { |
| try { |
| factoryClassName = rd.readLine(); |
| } catch (IOException x) { |
| // No provider found |
| break; |
| } |
| if (factoryClassName != null) { |
| // Ignore comments in the provider-configuration file |
| int hashIndex = factoryClassName.indexOf('#'); |
| if (hashIndex != -1) { |
| factoryClassName = factoryClassName.substring(0, hashIndex); |
| } |
| |
| // Ignore leading and trailing whitespace |
| factoryClassName = factoryClassName.trim(); |
| |
| // If there's no text left or if this was a blank line, go to the next one. |
| if (factoryClassName.length() == 0) { |
| continue; |
| } |
| |
| try { |
| // Found the right SchemaFactory if its isSchemaLanguageSupported(schemaLanguage) method returns true. |
| SchemaFactory foundFactory = (SchemaFactory) createInstance(factoryClassName); |
| if (foundFactory.isSchemaLanguageSupported(schemaLanguage)) { |
| resultFactory = foundFactory; |
| break; |
| } |
| } |
| catch (Exception ignored) {} |
| } |
| else { |
| break; |
| } |
| } |
| |
| IoUtils.closeQuietly(rd); |
| |
| return resultFactory; |
| } |
| |
| private static final Class SERVICE_CLASS = SchemaFactory.class; |
| private static final String SERVICE_ID = "META-INF/services/" + SERVICE_CLASS.getName(); |
| |
| private static String which( Class clazz ) { |
| return which( clazz.getName(), clazz.getClassLoader() ); |
| } |
| |
| /** |
| * <p>Search the specified classloader for the given classname.</p> |
| * |
| * @param classname the fully qualified name of the class to search for |
| * @param loader the classloader to search |
| * |
| * @return the source location of the resource, or null if it wasn't found |
| */ |
| private static String which(String classname, ClassLoader loader) { |
| String classnameAsResource = classname.replace('.', '/') + ".class"; |
| |
| if (loader == null) loader = ClassLoader.getSystemClassLoader(); |
| |
| URL it = loader.getResource(classnameAsResource); |
| return it != null ? it.toString() : null; |
| } |
| } |
