v1/src/typeimpl/org/apache/xmlbeans/impl/schema/SchemaTypeLoaderImpl.java - xmlbeans - Git at Google

 /*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache
 *    XMLBeans", nor may "Apache" appear in their name, without prior
 *    written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2000-2003 BEA Systems
 * Inc., <http://www.bea.com/>. For more information on the Apache Software
 * Foundation, please see <http://www.apache.org/>.
 */

 package org.apache.xmlbeans.impl.schema;

 import org.apache.xmlbeans.SchemaTypeLoader;
 import org.apache.xmlbeans.SchemaType;
 import org.apache.xmlbeans.SchemaGlobalElement;
 import org.apache.xmlbeans.SchemaGlobalAttribute;
 import org.apache.xmlbeans.SchemaModelGroup;
 import org.apache.xmlbeans.SchemaAttributeGroup;
 import org.apache.xmlbeans.SchemaTypeSystem;
 import org.apache.xmlbeans.SchemaIdentityConstraint;
 import org.apache.xmlbeans.impl.common.QNameHelper;
 import org.apache.xmlbeans.impl.common.XBeanDebug;
 import javax.xml.namespace.QName;

 import java.io.InputStream;
 import java.util.Map;
 import java.util.HashMap;
 import java.util.WeakHashMap;
 import java.util.Collections;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.IdentityHashMap;

 public class SchemaTypeLoaderImpl extends SchemaTypeLoaderBase
 {
     private ResourceLoader _resourceLoader;
     private ClassLoader _classLoader;
     private SchemaTypeLoader[] _searchPath;

     private Map _classpathTypeSystems;
     private Map _classLoaderTypeSystems;
     private Map _elementCache;
     private Map _attributeCache;
     private Map _modelGroupCache;
     private Map _attributeGroupCache;
     private Map _idConstraintCache;
     private Map _typeCache;
     private Map _documentCache;
     private Map _classnameCache;

     private static SchemaTypeLoaderImpl buildContextTypeLoader()
     {
         return new SchemaTypeLoaderImpl(new SchemaTypeLoader[] { BuiltinSchemaTypeSystem.get() } , null, Thread.currentThread().getContextClassLoader());
     }

     private static ThreadLocal _threadTypeSystems =
         new ThreadLocal()
         {
             protected Object initialValue() { return new WeakHashMap(); }
         };

     public static SchemaTypeLoaderImpl getContextTypeLoader()
     {
         WeakHashMap candidates = (WeakHashMap) _threadTypeSystems.get();
         ClassLoader threadContextClassLoader = Thread.currentThread().getContextClassLoader();
         SchemaTypeLoaderImpl candidate = (SchemaTypeLoaderImpl) candidates.get( threadContextClassLoader );

         if (candidate == null)
         {
             candidate = buildContextTypeLoader();
             candidates.put( threadContextClassLoader, candidate );
         }
         return candidate;
     }

     public static SchemaTypeLoader build(SchemaTypeLoader[] searchPath, ResourceLoader resourceLoader, ClassLoader classLoader)
     {
         if (searchPath == null)
         {
             searchPath = EMPTY_SCHEMATYPELOADER_ARRAY;
         }
         else
         {
             // assemble a flattened search path with no duplicates
             SubLoaderList list = new SubLoaderList();
             for (int i = 0; i < searchPath.length; i++)
             {
                 if (searchPath[i] == null)
                     throw new IllegalArgumentException("searchPath[" + i + "] is null");
                 if (!(searchPath[i] instanceof SchemaTypeLoaderImpl))
                     list.add(searchPath[i]);
                 else
                 {
                     SchemaTypeLoaderImpl sub = (SchemaTypeLoaderImpl)searchPath[i];
                     if (sub._classLoader != null || sub._resourceLoader != null)
                         list.add(sub);
                     else for (int j = 0; j < sub._searchPath.length; j++)
                         list.add(sub._searchPath[j]);
                 }
             }
             searchPath = list.toArray();
         }

         if (searchPath.length == 1 && resourceLoader == null && classLoader == null)
             return searchPath[0];

         return new SchemaTypeLoaderImpl(searchPath, resourceLoader, classLoader);
     }

     /**
      * Just used to avoid duplicate path entries
      */
     private static class SubLoaderList
     {
         private List theList = new ArrayList();
         private Map seen = new IdentityHashMap();

         private boolean add(SchemaTypeLoader loader)
         {
             if (seen.containsKey(loader))
                 return false;
             theList.add(loader);
             seen.put(loader, null);
             return true;
         }

         private SchemaTypeLoader[] toArray()
         {
             return (SchemaTypeLoader[])theList.toArray(EMPTY_SCHEMATYPELOADER_ARRAY);
         }
     }

     /**
      * Constructs a SchemaTypeLoaderImpl that searches for objects
      * in the following order:
      *
      * (1) First on the searchPath of other SchemaTypeSystems supplied,
      *     in order that they are listed.
      * (2) Next on the classpath of .jar files or directories supplied,
      *     in the order that they are listed. When types are returned in
      *     this way, they are instantiated from a private typesystem.
      *     In other words, if a type is loaded from another SchemaTypeLoaderImpl
      *     that was initialized on the same file, the instance of the type will
      *     be different.
      * (3) Finally on the classloader supplied.
      */
     private SchemaTypeLoaderImpl(SchemaTypeLoader[] searchPath, ResourceLoader resourceLoader, ClassLoader classLoader)
     {
         if (searchPath == null)
             _searchPath = EMPTY_SCHEMATYPELOADER_ARRAY;
         else
             _searchPath = searchPath;
         _resourceLoader = resourceLoader;
         _classLoader = classLoader;

         initCaches();
     }

     /**
      * Initializes the caches.
      */
     private final void initCaches()
     {
         _classpathTypeSystems = Collections.synchronizedMap(new HashMap());
         _classLoaderTypeSystems = Collections.synchronizedMap(new HashMap());
         _elementCache = Collections.synchronizedMap(new HashMap());
         _attributeCache = Collections.synchronizedMap(new HashMap());
         _modelGroupCache = Collections.synchronizedMap(new HashMap());
         _attributeGroupCache = Collections.synchronizedMap(new HashMap());
         _idConstraintCache = Collections.synchronizedMap(new HashMap());
         _typeCache = Collections.synchronizedMap(new HashMap());
         _documentCache = Collections.synchronizedMap(new HashMap());
         _classnameCache = Collections.synchronizedMap(new HashMap());
     }

     SchemaTypeSystemImpl typeSystemForComponent(String searchdir, QName name)
     {
         String searchfor = searchdir + QNameHelper.hexsafedir(name) + ".xsb";
         String tsname = null;

         if (_resourceLoader != null)
             tsname = crackEntry(_resourceLoader, searchfor);

         if (_classLoader != null)
             tsname = crackEntry(_classLoader, searchfor);

         if (tsname != null)
             return (SchemaTypeSystemImpl)typeSystemForName(tsname);

         return null;
     }

     public SchemaTypeSystem typeSystemForName(String name)
     {
         if (_resourceLoader != null)
         {
             SchemaTypeSystem result = getTypeSystemOnClasspath(name);
             if (result != null)
                 return result;
         }

         if (_classLoader != null)
         {
             SchemaTypeSystem result = getTypeSystemOnClassloader(name);
             if (result != null)
                 return result;
         }
         return null;
     }

     SchemaTypeSystemImpl typeSystemForClassname(String searchdir, String name)
     {
         String searchfor = searchdir + name.replace('.', '/') + ".xsb";

         if (_resourceLoader != null)
         {
             String tsname = crackEntry(_resourceLoader, searchfor);
             if (tsname != null)
                 return getTypeSystemOnClasspath(tsname);
         }

         if (_classLoader != null)
         {
             String tsname = crackEntry(_classLoader, searchfor);
             if (tsname != null)
                 return getTypeSystemOnClassloader(tsname);
         }

         return null;
     }

     SchemaTypeSystemImpl getTypeSystemOnClasspath(String name)
     {
         SchemaTypeSystemImpl result = (SchemaTypeSystemImpl)_classpathTypeSystems.get(name);
         if (result == null)
         {
             result = new SchemaTypeSystemImpl(_resourceLoader, name, this);
             _classpathTypeSystems.put(name, result);
         }
         return result;
     }

     SchemaTypeSystemImpl getTypeSystemOnClassloader(String name)
     {
         XBeanDebug.trace(XBeanDebug.TRACE_SCHEMA_LOADING, "Finding type system " + name + " on classloader", 0);
         SchemaTypeSystemImpl result = (SchemaTypeSystemImpl)_classLoaderTypeSystems.get(name);
         if (result == null)
         {
             XBeanDebug.trace(XBeanDebug.TRACE_SCHEMA_LOADING, "Type system " + name + " not cached - consulting field", 0);
             result = SchemaTypeSystemImpl.forName(name, _classLoader);
             _classLoaderTypeSystems.put(name, result);
         }
         return result;
     }

     static String crackEntry(ResourceLoader loader, String searchfor)
     {
         InputStream is = loader.getResourceAsStream(searchfor);
         if (is == null)
             return null;
         return crackPointer(is);
     }

     static String crackEntry(ClassLoader loader, String searchfor)
     {
         InputStream stream = loader.getResourceAsStream(searchfor);
         if (stream == null)
             return null;
         return crackPointer(stream);
     }

     static String crackPointer(InputStream stream)
     {
         return SchemaTypeSystemImpl.crackPointer(stream);
     }

     public boolean isNamespaceDefined(String namespace)
     {
         for (int i = 0; i < _searchPath.length; i++)
             if (_searchPath[i].isNamespaceDefined(namespace))
                 return true;

         SchemaTypeSystem sts = typeSystemForComponent("schema/namespace/", new QName(namespace, "xmlns"));
         return (sts != null);
     }

     public SchemaType.Ref findTypeRef(QName name)
     {
         SchemaType.Ref result = (SchemaType.Ref)_typeCache.get(name);
         if (result == null && !_typeCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findTypeRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/type/", name);
                 if (ts != null)
                 {
                     result = ts.findTypeRef(name);
                     assert(result != null) : "Type system registered type " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _typeCache.put(name, result);
         }
         return result;
     }

     public SchemaType typeForClassname(String classname)
     {
         classname = classname.replace('$', '.');

         SchemaType result = (SchemaType)_classnameCache.get(classname);
         if (result == null && !_classnameCache.containsKey(classname))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].typeForClassname(classname)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForClassname("schema/javaname/", classname);
                 if (ts != null)
                 {
                     result = ts.typeForClassname(classname);
                     assert(result != null) : "Type system registered type " + classname + " but does not return it";
                 }
             }
             _classnameCache.put(classname, result);
         }
         return result;
     }

     public SchemaType.Ref findDocumentTypeRef(QName name)
     {
         SchemaType.Ref result = (SchemaType.Ref)_documentCache.get(name);
         if (result == null && !_documentCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findDocumentTypeRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/element/", name);
                 if (ts != null)
                 {
                     result = ts.findDocumentTypeRef(name);
                     assert(result != null) : "Type system registered element " + QNameHelper.pretty(name) + " but does not contain document type";
                 }
             }
             _documentCache.put(name, result);
         }
         return result;
     }

     public SchemaType.Ref findAttributeTypeRef(QName name)
     {
         SchemaType.Ref result = (SchemaType.Ref)_attributeCache.get(name);
         if (result == null && !_attributeCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findAttributeTypeRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/attribute/", name);
                 if (ts != null)
                 {
                     result = ts.findAttributeTypeRef(name);
                     assert(result != null) : "Type system registered attribute " + QNameHelper.pretty(name) + " but does not contain attribute type";
                 }
             }
             _attributeCache.put(name, result);
         }
         return result;
     }

     public SchemaGlobalElement.Ref findElementRef(QName name)
     {
         SchemaGlobalElement.Ref result = (SchemaGlobalElement.Ref)_elementCache.get(name);
         if (result == null && !_elementCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findElementRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/element/", name);
                 if (ts != null)
                 {
                     result = ts.findElementRef(name);
                     assert(result != null) : "Type system registered element " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _elementCache.put(name, result);
         }
         return result;
     }

     public SchemaGlobalAttribute.Ref findAttributeRef(QName name)
     {
         SchemaGlobalAttribute.Ref result = (SchemaGlobalAttribute.Ref)_attributeCache.get(name);
         if (result == null && !_attributeCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findAttributeRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/attribute/", name);
                 if (ts != null)
                 {
                     result = ts.findAttributeRef(name);
                     assert(result != null) : "Type system registered attribute " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _attributeCache.put(name, result);
         }
         return result;
     }

     public SchemaModelGroup.Ref findModelGroupRef(QName name)
     {
         SchemaModelGroup.Ref result = (SchemaModelGroup.Ref)_modelGroupCache.get(name);
         if (result == null && !_modelGroupCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findModelGroupRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/modelgroup/", name);
                 if (ts != null)
                 {
                     result = ts.findModelGroupRef(name);
                     assert(result != null) : "Type system registered model group " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _modelGroupCache.put(name, result);
         }
         return result;
     }

     public SchemaAttributeGroup.Ref findAttributeGroupRef(QName name)
     {
         SchemaAttributeGroup.Ref result = (SchemaAttributeGroup.Ref)_attributeGroupCache.get(name);
         if (result == null && !_attributeGroupCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findAttributeGroupRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/attributegroup/", name);
                 if (ts != null)
                 {
                     result = ts.findAttributeGroupRef(name);
                     assert(result != null) : "Type system registered attribute group " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _attributeGroupCache.put(name, result);
         }
         return result;
     }

     public SchemaIdentityConstraint.Ref findIdentityConstraintRef(QName name)
     {
         SchemaIdentityConstraint.Ref result = (SchemaIdentityConstraint.Ref)_idConstraintCache.get(name);
         if (result == null && !_idConstraintCache.containsKey(name))
         {
             for (int i = 0; i < _searchPath.length; i++)
                 if (null != (result = _searchPath[i].findIdentityConstraintRef(name)))
                     break;
             if (result == null)
             {
                 SchemaTypeSystem ts = typeSystemForComponent("schema/identityconstraint/", name);
                 if (ts != null)
                 {
                     result = ts.findIdentityConstraintRef(name);
                     assert(result != null) : "Type system registered identity constraint " + QNameHelper.pretty(name) + " but does not return it";
                 }
             }
             _idConstraintCache.put(name, result);
         }
         return result;
     }

     public InputStream getSourceAsStream(String sourceName)
     {
         InputStream result = null;

         if (!sourceName.startsWith("/"))
             sourceName = "/" + sourceName;

         if (_resourceLoader != null)
             result = _resourceLoader.getResourceAsStream("schema/src" + sourceName);

         if (result == null && _classLoader != null)
             return _classLoader.getResourceAsStream("schema/src" + sourceName);

         return result;
     }

     private static final SchemaTypeLoader[] EMPTY_SCHEMATYPELOADER_ARRAY = new SchemaTypeLoader[0];
 }
	/*
	* The Apache Software License, Version 1.1
	*
	*
	* Copyright (c) 2003 The Apache Software Foundation. All rights
	* reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	*
	* 3. The end-user documentation included with the redistribution,
	* if any, must include the following acknowledgment:
	* "This product includes software developed by the
	* Apache Software Foundation (http://www.apache.org/)."
	* Alternately, this acknowledgment may appear in the software itself,
	* if and wherever such third-party acknowledgments normally appear.
	*
	* 4. The names "Apache" and "Apache Software Foundation" must
	* not be used to endorse or promote products derived from this
	* software without prior written permission. For written
	* permission, please contact apache@apache.org.
	*
	* 5. Products derived from this software may not be called "Apache
	* XMLBeans", nor may "Apache" appear in their name, without prior
	* written permission of the Apache Software Foundation.
	*
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
	* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	* ====================================================================
	*
	* This software consists of voluntary contributions made by many
	* individuals on behalf of the Apache Software Foundation and was
	* originally based on software copyright (c) 2000-2003 BEA Systems
	* Inc., <http://www.bea.com/>. For more information on the Apache Software
	* Foundation, please see <http://www.apache.org/>.
	*/

	package org.apache.xmlbeans.impl.schema;

	import org.apache.xmlbeans.SchemaTypeLoader;
	import org.apache.xmlbeans.SchemaType;
	import org.apache.xmlbeans.SchemaGlobalElement;
	import org.apache.xmlbeans.SchemaGlobalAttribute;
	import org.apache.xmlbeans.SchemaModelGroup;
	import org.apache.xmlbeans.SchemaAttributeGroup;
	import org.apache.xmlbeans.SchemaTypeSystem;
	import org.apache.xmlbeans.SchemaIdentityConstraint;
	import org.apache.xmlbeans.impl.common.QNameHelper;
	import org.apache.xmlbeans.impl.common.XBeanDebug;
	import javax.xml.namespace.QName;

	import java.io.InputStream;
	import java.util.Map;
	import java.util.HashMap;
	import java.util.WeakHashMap;
	import java.util.Collections;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.IdentityHashMap;

	public class SchemaTypeLoaderImpl extends SchemaTypeLoaderBase
	{
	private ResourceLoader _resourceLoader;
	private ClassLoader _classLoader;
	private SchemaTypeLoader[] _searchPath;

	private Map _classpathTypeSystems;
	private Map _classLoaderTypeSystems;
	private Map _elementCache;
	private Map _attributeCache;
	private Map _modelGroupCache;
	private Map _attributeGroupCache;
	private Map _idConstraintCache;
	private Map _typeCache;
	private Map _documentCache;
	private Map _classnameCache;

	private static SchemaTypeLoaderImpl buildContextTypeLoader()
	{
	return new SchemaTypeLoaderImpl(new SchemaTypeLoader[] { BuiltinSchemaTypeSystem.get() } , null, Thread.currentThread().getContextClassLoader());
	}

	private static ThreadLocal _threadTypeSystems =
	new ThreadLocal()
	{
	protected Object initialValue() { return new WeakHashMap(); }
	};

	public static SchemaTypeLoaderImpl getContextTypeLoader()
	{
	WeakHashMap candidates = (WeakHashMap) _threadTypeSystems.get();
	ClassLoader threadContextClassLoader = Thread.currentThread().getContextClassLoader();
	SchemaTypeLoaderImpl candidate = (SchemaTypeLoaderImpl) candidates.get( threadContextClassLoader );

	if (candidate == null)
	{
	candidate = buildContextTypeLoader();
	candidates.put( threadContextClassLoader, candidate );
	}
	return candidate;
	}

	public static SchemaTypeLoader build(SchemaTypeLoader[] searchPath, ResourceLoader resourceLoader, ClassLoader classLoader)
	{
	if (searchPath == null)
	{
	searchPath = EMPTY_SCHEMATYPELOADER_ARRAY;
	}
	else
	{
	// assemble a flattened search path with no duplicates
	SubLoaderList list = new SubLoaderList();
	for (int i = 0; i < searchPath.length; i++)
	{
	if (searchPath[i] == null)
	throw new IllegalArgumentException("searchPath[" + i + "] is null");
	if (!(searchPath[i] instanceof SchemaTypeLoaderImpl))
	list.add(searchPath[i]);
	else
	{
	SchemaTypeLoaderImpl sub = (SchemaTypeLoaderImpl)searchPath[i];
	if (sub._classLoader != null \|\| sub._resourceLoader != null)
	list.add(sub);
	else for (int j = 0; j < sub._searchPath.length; j++)
	list.add(sub._searchPath[j]);
	}
	}
	searchPath = list.toArray();
	}

	if (searchPath.length == 1 && resourceLoader == null && classLoader == null)
	return searchPath[0];

	return new SchemaTypeLoaderImpl(searchPath, resourceLoader, classLoader);
	}

	/**
	* Just used to avoid duplicate path entries
	*/
	private static class SubLoaderList
	{
	private List theList = new ArrayList();
	private Map seen = new IdentityHashMap();

	private boolean add(SchemaTypeLoader loader)
	{
	if (seen.containsKey(loader))
	return false;
	theList.add(loader);
	seen.put(loader, null);
	return true;
	}

	private SchemaTypeLoader[] toArray()
	{
	return (SchemaTypeLoader[])theList.toArray(EMPTY_SCHEMATYPELOADER_ARRAY);
	}
	}

	/**
	* Constructs a SchemaTypeLoaderImpl that searches for objects
	* in the following order:
	*
	* (1) First on the searchPath of other SchemaTypeSystems supplied,
	* in order that they are listed.
	* (2) Next on the classpath of .jar files or directories supplied,
	* in the order that they are listed. When types are returned in
	* this way, they are instantiated from a private typesystem.
	* In other words, if a type is loaded from another SchemaTypeLoaderImpl
	* that was initialized on the same file, the instance of the type will
	* be different.
	* (3) Finally on the classloader supplied.
	*/
	private SchemaTypeLoaderImpl(SchemaTypeLoader[] searchPath, ResourceLoader resourceLoader, ClassLoader classLoader)
	{
	if (searchPath == null)
	_searchPath = EMPTY_SCHEMATYPELOADER_ARRAY;
	else
	_searchPath = searchPath;
	_resourceLoader = resourceLoader;
	_classLoader = classLoader;

	initCaches();
	}

	/**
	* Initializes the caches.
	*/
	private final void initCaches()
	{
	_classpathTypeSystems = Collections.synchronizedMap(new HashMap());
	_classLoaderTypeSystems = Collections.synchronizedMap(new HashMap());
	_elementCache = Collections.synchronizedMap(new HashMap());
	_attributeCache = Collections.synchronizedMap(new HashMap());
	_modelGroupCache = Collections.synchronizedMap(new HashMap());
	_attributeGroupCache = Collections.synchronizedMap(new HashMap());
	_idConstraintCache = Collections.synchronizedMap(new HashMap());
	_typeCache = Collections.synchronizedMap(new HashMap());
	_documentCache = Collections.synchronizedMap(new HashMap());
	_classnameCache = Collections.synchronizedMap(new HashMap());
	}

	SchemaTypeSystemImpl typeSystemForComponent(String searchdir, QName name)
	{
	String searchfor = searchdir + QNameHelper.hexsafedir(name) + ".xsb";
	String tsname = null;

	if (_resourceLoader != null)
	tsname = crackEntry(_resourceLoader, searchfor);

	if (_classLoader != null)
	tsname = crackEntry(_classLoader, searchfor);

	if (tsname != null)
	return (SchemaTypeSystemImpl)typeSystemForName(tsname);

	return null;
	}

	public SchemaTypeSystem typeSystemForName(String name)
	{
	if (_resourceLoader != null)
	{
	SchemaTypeSystem result = getTypeSystemOnClasspath(name);
	if (result != null)
	return result;
	}

	if (_classLoader != null)
	{
	SchemaTypeSystem result = getTypeSystemOnClassloader(name);
	if (result != null)
	return result;
	}
	return null;
	}

	SchemaTypeSystemImpl typeSystemForClassname(String searchdir, String name)
	{
	String searchfor = searchdir + name.replace('.', '/') + ".xsb";

	if (_resourceLoader != null)
	{
	String tsname = crackEntry(_resourceLoader, searchfor);
	if (tsname != null)
	return getTypeSystemOnClasspath(tsname);
	}

	if (_classLoader != null)
	{
	String tsname = crackEntry(_classLoader, searchfor);
	if (tsname != null)
	return getTypeSystemOnClassloader(tsname);
	}

	return null;
	}

	SchemaTypeSystemImpl getTypeSystemOnClasspath(String name)
	{
	SchemaTypeSystemImpl result = (SchemaTypeSystemImpl)_classpathTypeSystems.get(name);
	if (result == null)
	{
	result = new SchemaTypeSystemImpl(_resourceLoader, name, this);
	_classpathTypeSystems.put(name, result);
	}
	return result;
	}

	SchemaTypeSystemImpl getTypeSystemOnClassloader(String name)
	{
	XBeanDebug.trace(XBeanDebug.TRACE_SCHEMA_LOADING, "Finding type system " + name + " on classloader", 0);
	SchemaTypeSystemImpl result = (SchemaTypeSystemImpl)_classLoaderTypeSystems.get(name);
	if (result == null)
	{
	XBeanDebug.trace(XBeanDebug.TRACE_SCHEMA_LOADING, "Type system " + name + " not cached - consulting field", 0);
	result = SchemaTypeSystemImpl.forName(name, _classLoader);
	_classLoaderTypeSystems.put(name, result);
	}
	return result;
	}

	static String crackEntry(ResourceLoader loader, String searchfor)
	{
	InputStream is = loader.getResourceAsStream(searchfor);
	if (is == null)
	return null;
	return crackPointer(is);
	}

	static String crackEntry(ClassLoader loader, String searchfor)
	{
	InputStream stream = loader.getResourceAsStream(searchfor);
	if (stream == null)
	return null;
	return crackPointer(stream);
	}

	static String crackPointer(InputStream stream)
	{
	return SchemaTypeSystemImpl.crackPointer(stream);
	}

	public boolean isNamespaceDefined(String namespace)
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (_searchPath[i].isNamespaceDefined(namespace))
	return true;

	SchemaTypeSystem sts = typeSystemForComponent("schema/namespace/", new QName(namespace, "xmlns"));
	return (sts != null);
	}

	public SchemaType.Ref findTypeRef(QName name)
	{
	SchemaType.Ref result = (SchemaType.Ref)_typeCache.get(name);
	if (result == null && !_typeCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findTypeRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/type/", name);
	if (ts != null)
	{
	result = ts.findTypeRef(name);
	assert(result != null) : "Type system registered type " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_typeCache.put(name, result);
	}
	return result;
	}

	public SchemaType typeForClassname(String classname)
	{
	classname = classname.replace('$', '.');

	SchemaType result = (SchemaType)_classnameCache.get(classname);
	if (result == null && !_classnameCache.containsKey(classname))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].typeForClassname(classname)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForClassname("schema/javaname/", classname);
	if (ts != null)
	{
	result = ts.typeForClassname(classname);
	assert(result != null) : "Type system registered type " + classname + " but does not return it";
	}
	}
	_classnameCache.put(classname, result);
	}
	return result;
	}

	public SchemaType.Ref findDocumentTypeRef(QName name)
	{
	SchemaType.Ref result = (SchemaType.Ref)_documentCache.get(name);
	if (result == null && !_documentCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findDocumentTypeRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/element/", name);
	if (ts != null)
	{
	result = ts.findDocumentTypeRef(name);
	assert(result != null) : "Type system registered element " + QNameHelper.pretty(name) + " but does not contain document type";
	}
	}
	_documentCache.put(name, result);
	}
	return result;
	}

	public SchemaType.Ref findAttributeTypeRef(QName name)
	{
	SchemaType.Ref result = (SchemaType.Ref)_attributeCache.get(name);
	if (result == null && !_attributeCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findAttributeTypeRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/attribute/", name);
	if (ts != null)
	{
	result = ts.findAttributeTypeRef(name);
	assert(result != null) : "Type system registered attribute " + QNameHelper.pretty(name) + " but does not contain attribute type";
	}
	}
	_attributeCache.put(name, result);
	}
	return result;
	}

	public SchemaGlobalElement.Ref findElementRef(QName name)
	{
	SchemaGlobalElement.Ref result = (SchemaGlobalElement.Ref)_elementCache.get(name);
	if (result == null && !_elementCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findElementRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/element/", name);
	if (ts != null)
	{
	result = ts.findElementRef(name);
	assert(result != null) : "Type system registered element " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_elementCache.put(name, result);
	}
	return result;
	}

	public SchemaGlobalAttribute.Ref findAttributeRef(QName name)
	{
	SchemaGlobalAttribute.Ref result = (SchemaGlobalAttribute.Ref)_attributeCache.get(name);
	if (result == null && !_attributeCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findAttributeRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/attribute/", name);
	if (ts != null)
	{
	result = ts.findAttributeRef(name);
	assert(result != null) : "Type system registered attribute " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_attributeCache.put(name, result);
	}
	return result;
	}

	public SchemaModelGroup.Ref findModelGroupRef(QName name)
	{
	SchemaModelGroup.Ref result = (SchemaModelGroup.Ref)_modelGroupCache.get(name);
	if (result == null && !_modelGroupCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findModelGroupRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/modelgroup/", name);
	if (ts != null)
	{
	result = ts.findModelGroupRef(name);
	assert(result != null) : "Type system registered model group " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_modelGroupCache.put(name, result);
	}
	return result;
	}

	public SchemaAttributeGroup.Ref findAttributeGroupRef(QName name)
	{
	SchemaAttributeGroup.Ref result = (SchemaAttributeGroup.Ref)_attributeGroupCache.get(name);
	if (result == null && !_attributeGroupCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findAttributeGroupRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/attributegroup/", name);
	if (ts != null)
	{
	result = ts.findAttributeGroupRef(name);
	assert(result != null) : "Type system registered attribute group " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_attributeGroupCache.put(name, result);
	}
	return result;
	}

	public SchemaIdentityConstraint.Ref findIdentityConstraintRef(QName name)
	{
	SchemaIdentityConstraint.Ref result = (SchemaIdentityConstraint.Ref)_idConstraintCache.get(name);
	if (result == null && !_idConstraintCache.containsKey(name))
	{
	for (int i = 0; i < _searchPath.length; i++)
	if (null != (result = _searchPath[i].findIdentityConstraintRef(name)))
	break;
	if (result == null)
	{
	SchemaTypeSystem ts = typeSystemForComponent("schema/identityconstraint/", name);
	if (ts != null)
	{
	result = ts.findIdentityConstraintRef(name);
	assert(result != null) : "Type system registered identity constraint " + QNameHelper.pretty(name) + " but does not return it";
	}
	}
	_idConstraintCache.put(name, result);
	}
	return result;
	}

	public InputStream getSourceAsStream(String sourceName)
	{
	InputStream result = null;

	if (!sourceName.startsWith("/"))
	sourceName = "/" + sourceName;

	if (_resourceLoader != null)
	result = _resourceLoader.getResourceAsStream("schema/src" + sourceName);

	if (result == null && _classLoader != null)
	return _classLoader.getResourceAsStream("schema/src" + sourceName);

	return result;
	}

	private static final SchemaTypeLoader[] EMPTY_SCHEMATYPELOADER_ARRAY = new SchemaTypeLoader[0];
	}