src/javax/xml/validation/SchemaFactoryFinder.java - platform/external/jetbrains/jdk8u_jaxp - Git at Google

 /*
  * Copyright (c) 2003, 2013, 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 javax.xml.validation;

 import java.io.File;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.net.URL;
 import java.security.AccessControlContext;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 import java.util.Properties;
 import java.util.ServiceConfigurationError;
 import java.util.ServiceLoader;

 /**
  * Implementation of {@link SchemaFactory#newInstance(String)}.
  *
  * @author <a href="Kohsuke.Kawaguchi@Sun.com">Kohsuke Kawaguchi</a>
  * @version $Revision: 1.8 $, $Date: 2010-11-01 04:36:13 $
  * @since 1.5
  */
 class SchemaFactoryFinder  {

     /** debug support code. */
     private static boolean debug = false;
     /**
      *<p> Take care of restrictions imposed by java security model </p>
      */
     private static final SecuritySupport ss = new SecuritySupport();
     private static final String DEFAULT_PACKAGE = "com.sun.org.apache.xerces.internal";
     /**
      * <p>Cache properties for performance.</p>
      */
     private static final Properties cacheProps = new Properties();

     /**
      * <p>First time requires initialization overhead.</p>
      */
     private static volatile boolean firstTime = true;

     static {
         // Use try/catch block to support applets
         try {
             debug = ss.getSystemProperty("jaxp.debug") != null;
         } catch (Exception unused) {
             debug = false;
         }
     }

     /**
      * <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() {
         try {
             if( classLoader == ss.getContextClassLoader() ) {
                 debugPrintln("using thread context class loader ("+classLoader+") for search");
                 return;
             }
         } catch( Throwable unused ) {
             // getContextClassLoader() undefined in JDK1.1
         }

         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 <code>schemaLanguage</code> parameter is null.
      * @throws SchemaFactoryConfigurationError
      *      If a configuration error is encountered.
      */
     public SchemaFactory newFactory(String schemaLanguage) {
         if(schemaLanguage==null) {
             throw new NullPointerException();
         }
         SchemaFactory f = _newFactory(schemaLanguage);
         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 {
             debugPrintln("Looking up system property '"+propertyName+"'" );
             String r = ss.getSystemProperty(propertyName);
             if(r!=null) {
                 debugPrintln("The value is '"+r+"'");
                 sf = createInstance(r, true);
                 if(sf!=null)    return sf;
             } else
                 debugPrintln("The property is undefined.");
         } catch( Throwable t ) {
             if( debug ) {
                 debugPrintln("failed to look up system property '"+propertyName+"'" );
                 t.printStackTrace();
             }
         }

         String javah = ss.getSystemProperty( "java.home" );
         String configFile = javah + File.separator +
         "lib" + File.separator + "jaxp.properties";


         // try to read from $java.home/lib/jaxp.properties
         try {
             if(firstTime){
                 synchronized(cacheProps){
                     if(firstTime){
                         File f=new File( configFile );
                         firstTime = false;
                         if(ss.doesFileExist(f)){
                             debugPrintln("Read properties file " + f);
                             cacheProps.load(ss.getFileInputStream(f));
                         }
                     }
                 }
             }
             final String factoryClassName = cacheProps.getProperty(propertyName);
             debugPrintln("found " + factoryClassName + " in $java.home/jaxp.properties");

             if (factoryClassName != null) {
                 sf = createInstance(factoryClassName, true);
                 if(sf != null){
                     return sf;
                 }
             }
         } catch (Exception ex) {
             if (debug) {
                 ex.printStackTrace();
             }
         }

         // Try with ServiceLoader
         final SchemaFactory factoryImpl = findServiceProvider(schemaLanguage);

         // The following assertion should always be true.
         // Uncomment it, recompile, and run with -ea in case of doubts:
         // assert factoryImpl == null || factoryImpl.isSchemaLanguageSupported(schemaLanguage);

         if (factoryImpl != null) {
             return factoryImpl;
         }

         // platform default
         if(schemaLanguage.equals("http://www.w3.org/2001/XMLSchema")) {
             debugPrintln("attempting to use the platform default XML Schema validator");
             return createInstance("com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory", true);
         }

         debugPrintln("all things were tried, but none was found. bailing out.");
         return null;
     }

     /** <p>Create class using appropriate ClassLoader.</p>
      *
      * @param className Name of class to create.
      * @return Created class or <code>null</code>.
      */
     private Class<?> createClass(String className) {
         Class<?> clazz;
         // make sure we have access to restricted packages
         boolean internal = false;
         if (System.getSecurityManager() != null) {
             if (className != null && className.startsWith(DEFAULT_PACKAGE)) {
                 internal = true;
             }
         }

         try {
             if (classLoader != null && !internal) {
                 clazz = Class.forName(className, false, classLoader);
             } else {
                 clazz = Class.forName(className);
             }
         } catch (Throwable t) {
             if(debug)  {
                 t.printStackTrace();
             }
             return null;
         }

         return clazz;
     }

     /**
      * <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 ) {
         return createInstance( className, false );
     }

     SchemaFactory createInstance( String className, boolean useServicesMechanism ) {
         SchemaFactory schemaFactory = null;

         debugPrintln("createInstance(" + className + ")");

         // get Class from className
         Class<?> clazz = createClass(className);
         if (clazz == null) {
                 debugPrintln("failed to getClass(" + className + ")");
                 return null;
         }
         debugPrintln("loaded " + className + " from " + which(clazz));

         // instantiate Class as a SchemaFactory
         try {
                 if (!SchemaFactory.class.isAssignableFrom(clazz)) {
                     throw new ClassCastException(clazz.getName()
                                 + " cannot be cast to " + SchemaFactory.class);
                 }
                 if (!useServicesMechanism) {
                     schemaFactory = newInstanceNoServiceLoader(clazz);
                 }
                 if (schemaFactory == null) {
                     schemaFactory = (SchemaFactory) clazz.newInstance();
                 }
         } catch (ClassCastException classCastException) {
                 debugPrintln("could not instantiate " + clazz.getName());
                 if (debug) {
                         classCastException.printStackTrace();
                 }
                 return null;
         } catch (IllegalAccessException illegalAccessException) {
                 debugPrintln("could not instantiate " + clazz.getName());
                 if (debug) {
                         illegalAccessException.printStackTrace();
                 }
                 return null;
         } catch (InstantiationException instantiationException) {
                 debugPrintln("could not instantiate " + clazz.getName());
                 if (debug) {
                         instantiationException.printStackTrace();
                 }
                 return null;
         }

         return schemaFactory;
     }

     /**
      * Try to construct using newXMLSchemaFactoryNoServiceLoader
      *   method if available.
      */
     private static SchemaFactory newInstanceNoServiceLoader(
          Class<?> providerClass
     ) {
         // Retain maximum compatibility if no security manager.
         if (System.getSecurityManager() == null) {
             return null;
         }
         try {
             final Method creationMethod =
                 providerClass.getDeclaredMethod(
                     "newXMLSchemaFactoryNoServiceLoader"
                 );
             final int modifiers = creationMethod.getModifiers();

             // Do not call the method if it's not public static.
             if (!Modifier.isStatic(modifiers) || !Modifier.isPublic(modifiers)) {
                 return null;
             }

             // Only calls "newXMLSchemaFactoryNoServiceLoader" if it's
             // declared to return an instance of SchemaFactory.
             final Class<?> returnType = creationMethod.getReturnType();
             if (SERVICE_CLASS.isAssignableFrom(returnType)) {
                 return SERVICE_CLASS.cast(creationMethod.invoke(null, (Object[])null));
             } else {
                 // Should not happen since
                 // XMLSchemaFactory.newXMLSchemaFactoryNoServiceLoader is
                 // declared to return XMLSchemaFactory.
                 throw new ClassCastException(returnType
                             + " cannot be cast to " + SERVICE_CLASS);
             }
         } catch(ClassCastException e) {
             throw new SchemaFactoryConfigurationError(e.getMessage(), e);
         } catch (NoSuchMethodException exc) {
             return null;
         } catch (Exception exc) {
             return null;
         }
     }

     // Call isSchemaLanguageSupported with initial context.
     private boolean isSchemaLanguageSupportedBy(final SchemaFactory factory,
             final String schemaLanguage,
             AccessControlContext acc) {
         return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
             public Boolean run() {
                 return factory.isSchemaLanguageSupported(schemaLanguage);
             }
         }, acc);
     }

     /**
      * Finds a service provider subclass of SchemaFactory that supports the
      * given schema language using the ServiceLoader.
      *
      * @param schemaLanguage The schema language for which we seek a factory.
      * @return A SchemaFactory supporting the specified schema language, or null
      *         if none is found.
      * @throws SchemaFactoryConfigurationError if a configuration error is found.
      */
     private SchemaFactory findServiceProvider(final String schemaLanguage) {
         assert schemaLanguage != null;
         // store current context.
         final AccessControlContext acc = AccessController.getContext();
         try {
             return AccessController.doPrivileged(new PrivilegedAction<SchemaFactory>() {
                 public SchemaFactory run() {
                     final ServiceLoader<SchemaFactory> loader =
                             ServiceLoader.load(SERVICE_CLASS);
                     for (SchemaFactory factory : loader) {
                         // restore initial context to call
                         // factory.isSchemaLanguageSupported
                         if (isSchemaLanguageSupportedBy(factory, schemaLanguage, acc)) {
                             return factory;
                         }
                     }
                     return null; // no factory found.
                 }
             });
         } catch (ServiceConfigurationError error) {
             throw new SchemaFactoryConfigurationError(
                     "Provider for " + SERVICE_CLASS + " cannot be created", error);
         }
     }

     private static final Class<SchemaFactory> SERVICE_CLASS = SchemaFactory.class;


     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);
         URL it = ss.getResourceAsURL(loader, classnameAsResource);
         if (it != null) {
             return it.toString();
         } else {
             return null;
         }
     }
 }
	/*
	* Copyright (c) 2003, 2013, 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 javax.xml.validation;

	import java.io.File;
	import java.lang.reflect.Method;
	import java.lang.reflect.Modifier;
	import java.net.URL;
	import java.security.AccessControlContext;
	import java.security.AccessController;
	import java.security.PrivilegedAction;
	import java.util.Properties;
	import java.util.ServiceConfigurationError;
	import java.util.ServiceLoader;

	/**
	* Implementation of {@link SchemaFactory#newInstance(String)}.
	*
	* @author <a href="Kohsuke.Kawaguchi@Sun.com">Kohsuke Kawaguchi</a>
	* @version $Revision: 1.8 $, $Date: 2010-11-01 04:36:13 $
	* @since 1.5
	*/
	class SchemaFactoryFinder {

	/** debug support code. */
	private static boolean debug = false;
	/**
	*<p> Take care of restrictions imposed by java security model </p>
	*/
	private static final SecuritySupport ss = new SecuritySupport();
	private static final String DEFAULT_PACKAGE = "com.sun.org.apache.xerces.internal";
	/**
	* <p>Cache properties for performance.</p>
	*/
	private static final Properties cacheProps = new Properties();

	/**
	* <p>First time requires initialization overhead.</p>
	*/
	private static volatile boolean firstTime = true;

	static {
	// Use try/catch block to support applets
	try {
	debug = ss.getSystemProperty("jaxp.debug") != null;
	} catch (Exception unused) {
	debug = false;
	}
	}

	/**
	* <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() {
	try {
	if( classLoader == ss.getContextClassLoader() ) {
	debugPrintln("using thread context class loader ("+classLoader+") for search");
	return;
	}
	} catch( Throwable unused ) {
	// getContextClassLoader() undefined in JDK1.1
	}

	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 <code>schemaLanguage</code> parameter is null.
	* @throws SchemaFactoryConfigurationError
	* If a configuration error is encountered.
	*/
	public SchemaFactory newFactory(String schemaLanguage) {
	if(schemaLanguage==null) {
	throw new NullPointerException();
	}
	SchemaFactory f = _newFactory(schemaLanguage);
	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 {
	debugPrintln("Looking up system property '"+propertyName+"'" );
	String r = ss.getSystemProperty(propertyName);
	if(r!=null) {
	debugPrintln("The value is '"+r+"'");
	sf = createInstance(r, true);
	if(sf!=null) return sf;
	} else
	debugPrintln("The property is undefined.");
	} catch( Throwable t ) {
	if( debug ) {
	debugPrintln("failed to look up system property '"+propertyName+"'" );
	t.printStackTrace();
	}
	}

	String javah = ss.getSystemProperty( "java.home" );
	String configFile = javah + File.separator +
	"lib" + File.separator + "jaxp.properties";


	// try to read from $java.home/lib/jaxp.properties
	try {
	if(firstTime){
	synchronized(cacheProps){
	if(firstTime){
	File f=new File( configFile );
	firstTime = false;
	if(ss.doesFileExist(f)){
	debugPrintln("Read properties file " + f);
	cacheProps.load(ss.getFileInputStream(f));
	}
	}
	}
	}
	final String factoryClassName = cacheProps.getProperty(propertyName);
	debugPrintln("found " + factoryClassName + " in $java.home/jaxp.properties");

	if (factoryClassName != null) {
	sf = createInstance(factoryClassName, true);
	if(sf != null){
	return sf;
	}
	}
	} catch (Exception ex) {
	if (debug) {
	ex.printStackTrace();
	}
	}

	// Try with ServiceLoader
	final SchemaFactory factoryImpl = findServiceProvider(schemaLanguage);

	// The following assertion should always be true.
	// Uncomment it, recompile, and run with -ea in case of doubts:
	// assert factoryImpl == null \|\| factoryImpl.isSchemaLanguageSupported(schemaLanguage);

	if (factoryImpl != null) {
	return factoryImpl;
	}

	// platform default
	if(schemaLanguage.equals("http://www.w3.org/2001/XMLSchema")) {
	debugPrintln("attempting to use the platform default XML Schema validator");
	return createInstance("com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory", true);
	}

	debugPrintln("all things were tried, but none was found. bailing out.");
	return null;
	}

	/** <p>Create class using appropriate ClassLoader.</p>
	*
	* @param className Name of class to create.
	* @return Created class or <code>null</code>.
	*/
	private Class<?> createClass(String className) {
	Class<?> clazz;
	// make sure we have access to restricted packages
	boolean internal = false;
	if (System.getSecurityManager() != null) {
	if (className != null && className.startsWith(DEFAULT_PACKAGE)) {
	internal = true;
	}
	}

	try {
	if (classLoader != null && !internal) {
	clazz = Class.forName(className, false, classLoader);
	} else {
	clazz = Class.forName(className);
	}
	} catch (Throwable t) {
	if(debug) {
	t.printStackTrace();
	}
	return null;
	}

	return clazz;
	}

	/**
	* <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 ) {
	return createInstance( className, false );
	}

	SchemaFactory createInstance( String className, boolean useServicesMechanism ) {
	SchemaFactory schemaFactory = null;

	debugPrintln("createInstance(" + className + ")");

	// get Class from className
	Class<?> clazz = createClass(className);
	if (clazz == null) {
	debugPrintln("failed to getClass(" + className + ")");
	return null;
	}
	debugPrintln("loaded " + className + " from " + which(clazz));

	// instantiate Class as a SchemaFactory
	try {
	if (!SchemaFactory.class.isAssignableFrom(clazz)) {
	throw new ClassCastException(clazz.getName()
	+ " cannot be cast to " + SchemaFactory.class);
	}
	if (!useServicesMechanism) {
	schemaFactory = newInstanceNoServiceLoader(clazz);
	}
	if (schemaFactory == null) {
	schemaFactory = (SchemaFactory) clazz.newInstance();
	}
	} catch (ClassCastException classCastException) {
	debugPrintln("could not instantiate " + clazz.getName());
	if (debug) {
	classCastException.printStackTrace();
	}
	return null;
	} catch (IllegalAccessException illegalAccessException) {
	debugPrintln("could not instantiate " + clazz.getName());
	if (debug) {
	illegalAccessException.printStackTrace();
	}
	return null;
	} catch (InstantiationException instantiationException) {
	debugPrintln("could not instantiate " + clazz.getName());
	if (debug) {
	instantiationException.printStackTrace();
	}
	return null;
	}

	return schemaFactory;
	}

	/**
	* Try to construct using newXMLSchemaFactoryNoServiceLoader
	* method if available.
	*/
	private static SchemaFactory newInstanceNoServiceLoader(
	Class<?> providerClass
	) {
	// Retain maximum compatibility if no security manager.
	if (System.getSecurityManager() == null) {
	return null;
	}
	try {
	final Method creationMethod =
	providerClass.getDeclaredMethod(
	"newXMLSchemaFactoryNoServiceLoader"
	);
	final int modifiers = creationMethod.getModifiers();

	// Do not call the method if it's not public static.
	if (!Modifier.isStatic(modifiers) \|\| !Modifier.isPublic(modifiers)) {
	return null;
	}

	// Only calls "newXMLSchemaFactoryNoServiceLoader" if it's
	// declared to return an instance of SchemaFactory.
	final Class<?> returnType = creationMethod.getReturnType();
	if (SERVICE_CLASS.isAssignableFrom(returnType)) {
	return SERVICE_CLASS.cast(creationMethod.invoke(null, (Object[])null));
	} else {
	// Should not happen since
	// XMLSchemaFactory.newXMLSchemaFactoryNoServiceLoader is
	// declared to return XMLSchemaFactory.
	throw new ClassCastException(returnType
	+ " cannot be cast to " + SERVICE_CLASS);
	}
	} catch(ClassCastException e) {
	throw new SchemaFactoryConfigurationError(e.getMessage(), e);
	} catch (NoSuchMethodException exc) {
	return null;
	} catch (Exception exc) {
	return null;
	}
	}

	// Call isSchemaLanguageSupported with initial context.
	private boolean isSchemaLanguageSupportedBy(final SchemaFactory factory,
	final String schemaLanguage,
	AccessControlContext acc) {
	return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
	public Boolean run() {
	return factory.isSchemaLanguageSupported(schemaLanguage);
	}
	}, acc);
	}

	/**
	* Finds a service provider subclass of SchemaFactory that supports the
	* given schema language using the ServiceLoader.
	*
	* @param schemaLanguage The schema language for which we seek a factory.
	* @return A SchemaFactory supporting the specified schema language, or null
	* if none is found.
	* @throws SchemaFactoryConfigurationError if a configuration error is found.
	*/
	private SchemaFactory findServiceProvider(final String schemaLanguage) {
	assert schemaLanguage != null;
	// store current context.
	final AccessControlContext acc = AccessController.getContext();
	try {
	return AccessController.doPrivileged(new PrivilegedAction<SchemaFactory>() {
	public SchemaFactory run() {
	final ServiceLoader<SchemaFactory> loader =
	ServiceLoader.load(SERVICE_CLASS);
	for (SchemaFactory factory : loader) {
	// restore initial context to call
	// factory.isSchemaLanguageSupported
	if (isSchemaLanguageSupportedBy(factory, schemaLanguage, acc)) {
	return factory;
	}
	}
	return null; // no factory found.
	}
	});
	} catch (ServiceConfigurationError error) {
	throw new SchemaFactoryConfigurationError(
	"Provider for " + SERVICE_CLASS + " cannot be created", error);
	}
	}

	private static final Class<SchemaFactory> SERVICE_CLASS = SchemaFactory.class;


	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);
	URL it = ss.getResourceAsURL(loader, classnameAsResource);
	if (it != null) {
	return it.toString();
	} else {
	return null;
	}
	}
	}