/*
 * 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.
 */

package org.apache.xerces.impl.xs.traversers;

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Stack;
import java.util.Vector;

import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

import org.apache.xerces.impl.Constants;
import org.apache.xerces.impl.XMLEntityManager;
import org.apache.xerces.impl.XMLErrorReporter;
import org.apache.xerces.impl.dv.SchemaDVFactory;
import org.apache.xerces.impl.dv.xs.XSSimpleTypeDecl;
import org.apache.xerces.impl.xs.SchemaGrammar;
import org.apache.xerces.impl.xs.SchemaNamespaceSupport;
import org.apache.xerces.impl.xs.SchemaSymbols;
import org.apache.xerces.impl.xs.XMLSchemaException;
import org.apache.xerces.impl.xs.XMLSchemaLoader;
import org.apache.xerces.impl.xs.XSAttributeDecl;
import org.apache.xerces.impl.xs.XSAttributeGroupDecl;
import org.apache.xerces.impl.xs.XSComplexTypeDecl;
import org.apache.xerces.impl.xs.XSDDescription;
import org.apache.xerces.impl.xs.XSDeclarationPool;
import org.apache.xerces.impl.xs.XSElementDecl;
import org.apache.xerces.impl.xs.XSGrammarBucket;
import org.apache.xerces.impl.xs.XSGroupDecl;
import org.apache.xerces.impl.xs.XSMessageFormatter;
import org.apache.xerces.impl.xs.XSModelGroupImpl;
import org.apache.xerces.impl.xs.XSNotationDecl;
import org.apache.xerces.impl.xs.XSParticleDecl;
import org.apache.xerces.impl.xs.identity.IdentityConstraint;
import org.apache.xerces.impl.xs.opti.ElementImpl;
import org.apache.xerces.impl.xs.opti.SchemaDOMParser;
import org.apache.xerces.impl.xs.opti.SchemaParsingConfig;
import org.apache.xerces.impl.xs.util.SimpleLocator;
import org.apache.xerces.impl.xs.util.XSInputSource;
import org.apache.xerces.parsers.SAXParser;
import org.apache.xerces.parsers.XML11Configuration;
import org.apache.xerces.util.DOMInputSource;
import org.apache.xerces.util.DOMUtil;
import org.apache.xerces.util.DefaultErrorHandler;
import org.apache.xerces.util.ErrorHandlerWrapper;
import org.apache.xerces.util.SAXInputSource;
import org.apache.xerces.util.StAXInputSource;
import org.apache.xerces.util.StAXLocationWrapper;
import org.apache.xerces.util.SymbolHash;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.util.URI.MalformedURIException;
import org.apache.xerces.util.XMLSymbols;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.grammars.Grammar;
import org.apache.xerces.xni.grammars.XMLGrammarDescription;
import org.apache.xerces.xni.grammars.XMLGrammarPool;
import org.apache.xerces.xni.grammars.XMLSchemaDescription;
import org.apache.xerces.xni.parser.XMLComponentManager;
import org.apache.xerces.xni.parser.XMLConfigurationException;
import org.apache.xerces.xni.parser.XMLEntityResolver;
import org.apache.xerces.xni.parser.XMLErrorHandler;
import org.apache.xerces.xni.parser.XMLInputSource;
import org.apache.xerces.xni.parser.XMLParseException;
import org.apache.xerces.xs.StringList;
import org.apache.xerces.xs.XSAttributeDeclaration;
import org.apache.xerces.xs.XSAttributeGroupDefinition;
import org.apache.xerces.xs.XSAttributeUse;
import org.apache.xerces.xs.XSConstants;
import org.apache.xerces.xs.XSElementDeclaration;
import org.apache.xerces.xs.XSModelGroup;
import org.apache.xerces.xs.XSModelGroupDefinition;
import org.apache.xerces.xs.XSNamedMap;
import org.apache.xerces.xs.XSObject;
import org.apache.xerces.xs.XSObjectList;
import org.apache.xerces.xs.XSParticle;
import org.apache.xerces.xs.XSSimpleTypeDefinition;
import org.apache.xerces.xs.XSTerm;
import org.apache.xerces.xs.XSTypeDefinition;
import org.apache.xerces.xs.datatypes.ObjectList;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;


The purpose of this class is to co-ordinate the construction of a
grammar object corresponding to a schema.  To do this, it must be
prepared to parse several schema documents (for instance if the
schema document originally referred to contains  or
 information items).  If any of the schemas imports a
schema, other grammars may be constructed as a side-effect.
Author:
Neil Graham, IBM, Pavani Mukthipudi, Sun Microsystems
@xerces.internal
Version:
$Id: XSDHandler.java 1371253 2012-08-09 15:23:06Z sandygao $/**
 * The purpose of this class is to co-ordinate the construction of a
 * grammar object corresponding to a schema.  To do this, it must be
 * prepared to parse several schema documents (for instance if the
 * schema document originally referred to contains <include> or
 * <redefined> information items).  If any of the schemas imports a
 * schema, other grammars may be constructed as a side-effect.
 *
 * @xerces.internal 
 *
 * @author Neil Graham, IBM
 * @author Pavani Mukthipudi, Sun Microsystems
 * 
 * @version $Id: XSDHandler.java 1371253 2012-08-09 15:23:06Z sandygao $
 */
public class XSDHandler {
    
    
Feature identifier: validation. /** Feature identifier: validation. */
    protected static final String VALIDATION =
        Constants.SAX_FEATURE_PREFIX + Constants.VALIDATION_FEATURE;
    
    
feature identifier: XML Schema validation /** feature identifier: XML Schema validation */
    protected static final String XMLSCHEMA_VALIDATION =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_VALIDATION_FEATURE;
    
    
Feature identifier:  allow java encodings /** Feature identifier:  allow java encodings */
    protected static final String ALLOW_JAVA_ENCODINGS =
        Constants.XERCES_FEATURE_PREFIX + Constants.ALLOW_JAVA_ENCODINGS_FEATURE;
    
    
Feature identifier:  continue after fatal error /** Feature identifier:  continue after fatal error */
    protected static final String CONTINUE_AFTER_FATAL_ERROR =
        Constants.XERCES_FEATURE_PREFIX + Constants.CONTINUE_AFTER_FATAL_ERROR_FEATURE;
    
    
Feature identifier:  allow java encodings /** Feature identifier:  allow java encodings */
    protected static final String STANDARD_URI_CONFORMANT_FEATURE =
        Constants.XERCES_FEATURE_PREFIX + Constants.STANDARD_URI_CONFORMANT_FEATURE;
    
    
Feature: disallow doctype/** Feature: disallow doctype*/
    protected static final String DISALLOW_DOCTYPE =
        Constants.XERCES_FEATURE_PREFIX + Constants.DISALLOW_DOCTYPE_DECL_FEATURE;
    
    
Feature: generate synthetic annotations /** Feature: generate synthetic annotations */
    protected static final String GENERATE_SYNTHETIC_ANNOTATIONS = 
        Constants.XERCES_FEATURE_PREFIX + Constants.GENERATE_SYNTHETIC_ANNOTATIONS_FEATURE;
    
    
Feature identifier: validate annotations. /** Feature identifier: validate annotations. */
    protected static final String VALIDATE_ANNOTATIONS =
        Constants.XERCES_FEATURE_PREFIX + Constants.VALIDATE_ANNOTATIONS_FEATURE;
    
    
Feature identifier: honour all schemaLocations /** Feature identifier: honour all schemaLocations */
    protected static final String HONOUR_ALL_SCHEMALOCATIONS = 
      Constants.XERCES_FEATURE_PREFIX + Constants.HONOUR_ALL_SCHEMALOCATIONS_FEATURE;
    
    
Feature identifier: namespace growth /** Feature identifier: namespace growth */
    protected static final String NAMESPACE_GROWTH = 
      Constants.XERCES_FEATURE_PREFIX + Constants.NAMESPACE_GROWTH_FEATURE;

    
Feature identifier: tolerate duplicates /** Feature identifier: tolerate duplicates */
    protected static final String TOLERATE_DUPLICATES = 
      Constants.XERCES_FEATURE_PREFIX + Constants.TOLERATE_DUPLICATES_FEATURE;
    
    
Feature identifier: namespace prefixes. /** Feature identifier: namespace prefixes. */
    private static final String NAMESPACE_PREFIXES =
        Constants.SAX_FEATURE_PREFIX + Constants.NAMESPACE_PREFIXES_FEATURE;
    
    
Feature identifier: string interning. /** Feature identifier: string interning. */
    protected static final String STRING_INTERNING =
        Constants.SAX_FEATURE_PREFIX + Constants.STRING_INTERNING_FEATURE;
   
    
Property identifier: error handler. /** Property identifier: error handler. */
    protected static final String ERROR_HANDLER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ERROR_HANDLER_PROPERTY;
    
    
Property identifier: JAXP schema source. /** Property identifier: JAXP schema source. */
    protected static final String JAXP_SCHEMA_SOURCE =
        Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_SOURCE;
    
    
Property identifier: entity resolver. /** Property identifier: entity resolver. */
    public static final String ENTITY_RESOLVER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ENTITY_RESOLVER_PROPERTY;
    
Property identifier: entity manager. /** Property identifier: entity manager. */
    protected static final String ENTITY_MANAGER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ENTITY_MANAGER_PROPERTY;
    
    
Property identifier: error reporter. /** Property identifier: error reporter. */
    public static final String ERROR_REPORTER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ERROR_REPORTER_PROPERTY;
    
    
Property identifier: grammar pool. /** Property identifier: grammar pool. */
    public static final String XMLGRAMMAR_POOL =
        Constants.XERCES_PROPERTY_PREFIX + Constants.XMLGRAMMAR_POOL_PROPERTY;
    
    
Property identifier: symbol table. /** Property identifier: symbol table. */
    public static final String SYMBOL_TABLE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY;
    
    
Property identifier: security manager. /** Property identifier: security manager. */
    protected static final String SECURITY_MANAGER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SECURITY_MANAGER_PROPERTY;
    
    
Property identifier: locale. /** Property identifier: locale. */
    protected static final String LOCALE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.LOCALE_PROPERTY;
    
    protected static final boolean DEBUG_NODE_POOL = false;
    
    // Data
    
    // different sorts of declarations; should make lookup and
    // traverser calling more efficient/less bulky.
    final static int ATTRIBUTE_TYPE          = 1;
    final static int ATTRIBUTEGROUP_TYPE     = 2;
    final static int ELEMENT_TYPE            = 3;
    final static int GROUP_TYPE              = 4;
    final static int IDENTITYCONSTRAINT_TYPE = 5;
    final static int NOTATION_TYPE           = 6;
    final static int TYPEDECL_TYPE           = 7;
    
    // this string gets appended to redefined names; it's purpose is to be
    // as unlikely as possible to cause collisions.
    public final static String REDEF_IDENTIFIER = "_fn3dktizrknc9pi";
    
    //
    //protected data that can be accessable by any traverser
    // stores <notation> decl
    protected Hashtable fNotationRegistry = new Hashtable();
    
    protected XSDeclarationPool fDeclPool = null;
    
    
    // These tables correspond to the symbol spaces defined in the
    // spec.
    // They are keyed with a QName (that is, String("URI,localpart) and
    // their values are nodes corresponding to the given name's decl.
    // By asking the node for its ownerDocument and looking in
    // XSDocumentInfoRegistry we can easily get the corresponding
    // XSDocumentInfo object.
    private Hashtable fUnparsedAttributeRegistry = new Hashtable();
    private Hashtable fUnparsedAttributeGroupRegistry = new Hashtable();
    private Hashtable fUnparsedElementRegistry = new Hashtable();
    private Hashtable fUnparsedGroupRegistry = new Hashtable();
    private Hashtable fUnparsedIdentityConstraintRegistry = new Hashtable();
    private Hashtable fUnparsedNotationRegistry = new Hashtable();
    private Hashtable fUnparsedTypeRegistry = new Hashtable();
    // Compensation for the above hashtables to locate XSDocumentInfo, 
    // Since we may take Schema Element directly, so can not get the
    // corresponding XSDocumentInfo object just using above hashtables.
    private Hashtable fUnparsedAttributeRegistrySub = new Hashtable();
    private Hashtable fUnparsedAttributeGroupRegistrySub = new Hashtable();
    private Hashtable fUnparsedElementRegistrySub = new Hashtable();
    private Hashtable fUnparsedGroupRegistrySub = new Hashtable();
    private Hashtable fUnparsedIdentityConstraintRegistrySub = new Hashtable();
    private Hashtable fUnparsedNotationRegistrySub = new Hashtable();
    private Hashtable fUnparsedTypeRegistrySub = new Hashtable();

    // Stores XSDocumentInfo (keyed by component name), to check for duplicate
    // components declared within the same xsd document
    private Hashtable fUnparsedRegistriesExt[] = new Hashtable[] {
        null,
        new Hashtable(), // ATTRIBUTE_TYPE
        new Hashtable(), // ATTRIBUTEGROUP_TYPE
        new Hashtable(), // ELEMENT_TYPE
        new Hashtable(), // GROUP_TYPE
        new Hashtable(), // IDENTITYCONSTRAINT_TYPE
        new Hashtable(), // NOTATION_TYPE
        new Hashtable(), // TYPEDECL_TYPE
    };
    
    // this is keyed with a documentNode (or the schemaRoot nodes
    // contained in the XSDocumentInfo objects) and its value is the
    // XSDocumentInfo object corresponding to that document.
    // Basically, the function of this registry is to be a link
    // between the nodes we fetch from calls to the fUnparsed*
    // arrays and the XSDocumentInfos they live in.
    private Hashtable fXSDocumentInfoRegistry = new Hashtable();
    
    // this hashtable is keyed on by XSDocumentInfo objects.  Its values
    // are Vectors containing the XSDocumentInfo objects <include>d,
    // <import>ed or <redefine>d by the key XSDocumentInfo.
    private Hashtable fDependencyMap = new Hashtable();
    
    // this hashtable is keyed on by a target namespace.  Its values
    // are Vectors containing namespaces imported by schema documents
    // with the key target namespace.
    // if an imprted schema has absent namespace, the value "null" is stored.
    private Hashtable fImportMap = new Hashtable();
    // all namespaces that imports other namespaces
    // if the importing schema has absent namespace, empty string is stored.
    // (because the key of a hashtable can't be null.)
    private Vector fAllTNSs = new Vector();
    // stores instance document mappings between namespaces and schema hints
    private Hashtable fLocationPairs = null;
    private static final Hashtable EMPTY_TABLE = new Hashtable();
    
    // Records which nodes are hidden when the input is a DOMInputSource.
    Hashtable fHiddenNodes = null;

    // convenience methods
    private String null2EmptyString(String ns) {
        return ns == null ? XMLSymbols.EMPTY_STRING : ns;
    }
    private String emptyString2Null(String ns) {
        return ns == XMLSymbols.EMPTY_STRING ? null : ns;
    }
    // use Schema Element to lookup the SystemId.
    private String doc2SystemId(Element ele) {
        String documentURI = null;
        /**
         * REVISIT: Casting until DOM Level 3 interfaces are available. -- mrglavas
         */
        if(ele.getOwnerDocument() instanceof org.apache.xerces.impl.xs.opti.SchemaDOM){
            documentURI = ((org.apache.xerces.impl.xs.opti.SchemaDOM) ele.getOwnerDocument()).getDocumentURI();
        }
        return documentURI != null ? documentURI : (String) fDoc2SystemId.get(ele);
    }
    
    // This vector stores strings which are combinations of the
    // publicId and systemId of the inputSource corresponding to a
    // schema document.  This combination is used so that the user's
    // EntityResolver can provide a consistent way of identifying a
    // schema document that is included in multiple other schemas.
    private Hashtable fTraversed = new Hashtable();
    
    // this hashtable contains a mapping from Schema Element to its systemId
    // this is useful to resolve a uri relative to the referring document
    private Hashtable fDoc2SystemId = new Hashtable();
    
    // the primary XSDocumentInfo we were called to parse
    private XSDocumentInfo fRoot = null;
    
    // This hashtable's job is to act as a link between the Schema Element and its
    // XSDocumentInfo object.
    private Hashtable fDoc2XSDocumentMap = new Hashtable();
    
    // map between <redefine> elements and the XSDocumentInfo
    // objects that correspond to the documents being redefined.
    private Hashtable fRedefine2XSDMap = new Hashtable();
    
    // map between <redefine> elements and the namespace support
    private Hashtable fRedefine2NSSupport = new Hashtable();
    
    // these objects store a mapping between the names of redefining
    // groups/attributeGroups and the groups/AttributeGroups which
    // they redefine by restriction (implicitly).  It is up to the
    // Group and AttributeGroup traversers to check these restrictions for
    // validity.
    private Hashtable fRedefinedRestrictedAttributeGroupRegistry = new Hashtable();
    private Hashtable fRedefinedRestrictedGroupRegistry = new Hashtable();
    
    // a variable storing whether the last schema document
    // processed (by getSchema) was a duplicate.
    private boolean fLastSchemaWasDuplicate;
    
    // validate annotations feature
    private boolean fValidateAnnotations = false;
    
    //handle multiple import feature
    private boolean fHonourAllSchemaLocations = false;
    
    //handle namespace growth feature
    boolean fNamespaceGrowth = false;
    
    // handle tolerate duplicates feature
    boolean fTolerateDuplicates = false;

    // the XMLErrorReporter
    private XMLErrorReporter fErrorReporter;
    private XMLEntityResolver fEntityResolver;
    
    // the XSAttributeChecker
    private XSAttributeChecker fAttributeChecker;
    
    // the symbol table
    private SymbolTable fSymbolTable;
    
    // the GrammarResolver
    private XSGrammarBucket fGrammarBucket;
    
    // the Grammar description
    private XSDDescription fSchemaGrammarDescription;
    
    // the Grammar Pool
    private XMLGrammarPool fGrammarPool;
    
    //************ Traversers **********
    XSDAttributeGroupTraverser fAttributeGroupTraverser;
    XSDAttributeTraverser fAttributeTraverser;
    XSDComplexTypeTraverser fComplexTypeTraverser;
    XSDElementTraverser fElementTraverser;
    XSDGroupTraverser fGroupTraverser;
    XSDKeyrefTraverser fKeyrefTraverser;
    XSDNotationTraverser fNotationTraverser;
    XSDSimpleTypeTraverser fSimpleTypeTraverser;
    XSDUniqueOrKeyTraverser fUniqueOrKeyTraverser;
    XSDWildcardTraverser fWildCardTraverser;
    
    SchemaDVFactory fDVFactory;
    SchemaDOMParser fSchemaParser;
    SchemaContentHandler fXSContentHandler;
    StAXSchemaParser fStAXSchemaParser;
    XML11Configuration fAnnotationValidator;
    XSAnnotationGrammarPool fGrammarBucketAdapter;
    
    // these data members are needed for the deferred traversal
    // of local elements.
    
    // the initial size of the array to store deferred local elements
    private static final int INIT_STACK_SIZE = 30;
    // the incremental size of the array to store deferred local elements
    private static final int INC_STACK_SIZE  = 10;
    // current position of the array (# of deferred local elements)
    private int fLocalElemStackPos = 0;
    
    private XSParticleDecl[] fParticle = new XSParticleDecl[INIT_STACK_SIZE];
    private Element[] fLocalElementDecl = new Element[INIT_STACK_SIZE];
    private XSDocumentInfo[] fLocalElementDecl_schema = new XSDocumentInfo[INIT_STACK_SIZE]; //JACK
    private int[] fAllContext = new int[INIT_STACK_SIZE];
    private XSObject[] fParent = new XSObject[INIT_STACK_SIZE];
    private String [][] fLocalElemNamespaceContext = new String [INIT_STACK_SIZE][1];
    
    // these data members are needed for the deferred traversal
    // of keyrefs.
    
    // the initial size of the array to store deferred keyrefs
    private static final int INIT_KEYREF_STACK = 2;
    // the incremental size of the array to store deferred keyrefs
    private static final int INC_KEYREF_STACK_AMOUNT = 2;
    // current position of the array (# of deferred keyrefs)
    private int fKeyrefStackPos = 0;
    
    private Element [] fKeyrefs = new Element[INIT_KEYREF_STACK];
    private XSDocumentInfo [] fKeyrefsMapXSDocumentInfo = new XSDocumentInfo[INIT_KEYREF_STACK];
    private XSElementDecl [] fKeyrefElems = new XSElementDecl [INIT_KEYREF_STACK];
    private String [][] fKeyrefNamespaceContext = new String[INIT_KEYREF_STACK][1];
    
    // global decls: map from decl name to decl object
    SymbolHash fGlobalAttrDecls = new SymbolHash(12);
    SymbolHash fGlobalAttrGrpDecls = new SymbolHash(5);
    SymbolHash fGlobalElemDecls = new SymbolHash(25);
    SymbolHash fGlobalGroupDecls = new SymbolHash(5);
    SymbolHash fGlobalNotationDecls = new SymbolHash(1);
    SymbolHash fGlobalIDConstraintDecls = new SymbolHash(3);
    SymbolHash fGlobalTypeDecls = new SymbolHash(25);

    // Constructors
    public XSDHandler(){
        fHiddenNodes = new Hashtable();       
        fSchemaParser = new SchemaDOMParser(new SchemaParsingConfig());
    }
    
    // it should be possible to use the same XSDHandler to parse
    // multiple schema documents; this will allow one to be
    // constructed.
    public XSDHandler (XSGrammarBucket gBucket) {
        this();
        fGrammarBucket = gBucket;
        
        // Note: don't use SchemaConfiguration internally
        //       we will get stack overflaw because
        //       XMLSchemaValidator will be instantiating XSDHandler...
        fSchemaGrammarDescription = new XSDDescription();
    } // end constructor
       
    
This method initiates the parse of a schema.  It will likely be
called from the Validator and it will make the
resulting grammar available; it returns a reference to this object just
in case.  A reset(XMLComponentManager) must be called before this methods is called.
Params:
is – 
desc – 
locationPairs – 
Throws:
IOException – 
Returns:
the SchemaGrammar/**
     * This method initiates the parse of a schema.  It will likely be
     * called from the Validator and it will make the
     * resulting grammar available; it returns a reference to this object just
     * in case.  A reset(XMLComponentManager) must be called before this methods is called.
     * @param is
     * @param desc
     * @param locationPairs
     * @return the SchemaGrammar
     * @throws IOException
     */
    public SchemaGrammar parseSchema(XMLInputSource is, XSDDescription desc,
            Hashtable locationPairs)
    throws IOException {
        fLocationPairs = locationPairs;
        fSchemaParser.resetNodePool();   
        SchemaGrammar grammar = null;
        String schemaNamespace  = null;
        short referType = desc.getContextType();

        // if loading using JAXP schemaSource property, or using grammar caching loadGrammar
        // the desc.targetNamespace is always null.
        // Therefore we should not attempt to find out if
        // the schema is already in the bucket, since in the case we have
        // no namespace schema in the bucket, findGrammar will always return the
        // no namespace schema.
        if (referType != XSDDescription.CONTEXT_PREPARSE){
            // first try to find it in the bucket/pool, return if one is found
            if (fHonourAllSchemaLocations && referType == XSDDescription.CONTEXT_IMPORT && isExistingGrammar(desc, fNamespaceGrowth)) {
                grammar = fGrammarBucket.getGrammar(desc.getTargetNamespace());
            }
            else {
                grammar = findGrammar(desc, fNamespaceGrowth);
            }
            if (grammar != null) {
                if (!fNamespaceGrowth) {
                    return grammar;
                }
                else {
                    try {
                        if (grammar.getDocumentLocations().contains(XMLEntityManager.expandSystemId(is.getSystemId(), is.getBaseSystemId(), false))) {
                            return grammar; 
                        }
                    }
                    catch (MalformedURIException e) {
                        //REVISIT: return the grammar?
                    }
                }
            }

            schemaNamespace = desc.getTargetNamespace();
            // handle empty string URI as null
            if (schemaNamespace != null) {
                schemaNamespace = fSymbolTable.addSymbol(schemaNamespace);
            }
        }
        
        // before parsing a schema, need to clear registries associated with
        // parsing schemas
        prepareForParse();       
        
        Element schemaRoot = null;
        // first phase:  construct trees.
        if (is instanceof DOMInputSource) {
            schemaRoot = getSchemaDocument(schemaNamespace, (DOMInputSource) is,
                    referType == XSDDescription.CONTEXT_PREPARSE,
                    referType, null); 
        } // DOMInputSource
        else if (is instanceof SAXInputSource) {
        	schemaRoot = getSchemaDocument(schemaNamespace, (SAXInputSource) is,
                    referType == XSDDescription.CONTEXT_PREPARSE,
                    referType, null);     
        } // SAXInputSource
        else if (is instanceof StAXInputSource) {
            schemaRoot = getSchemaDocument(schemaNamespace, (StAXInputSource) is,
                    referType == XSDDescription.CONTEXT_PREPARSE,
                    referType, null);
        } // StAXInputSource
        else if (is instanceof XSInputSource) {
            schemaRoot = getSchemaDocument((XSInputSource) is, desc);
        } // XSInputSource
        else {
        	schemaRoot = getSchemaDocument(schemaNamespace, is,
                  referType == XSDDescription.CONTEXT_PREPARSE,
                  referType, null);
             
        } //is instanceof XMLInputSource

        if (schemaRoot == null) {
            if (is instanceof XSInputSource) {
                // Need to return a grammar. If the XSInputSource has a list
                // of grammar objects, then get the first one and return it.
                // If it has a list of components, then get the grammar that
                // contains the first component and return it.
                // If we return null, the XMLSchemaLoader will think nothing
                // was loaded, and will not try to put the grammar objects
                // into the grammar pool.
                XSInputSource xsinput = (XSInputSource)is;
                SchemaGrammar[] grammars = xsinput.getGrammars();
                if (grammars != null && grammars.length > 0) {
                    grammar = fGrammarBucket.getGrammar(grammars[0].getTargetNamespace());
                }
                else {
                    XSObject[] components = xsinput.getComponents();
                    if (components != null && components.length > 0) {
                        grammar = fGrammarBucket.getGrammar(components[0].getNamespace());
                    }
                }
            }
            // something went wrong right off the hop
            return grammar;
        }

        if (referType == XSDDescription.CONTEXT_PREPARSE) {
        	Element schemaElem = schemaRoot;
            schemaNamespace = DOMUtil.getAttrValue(schemaElem, SchemaSymbols.ATT_TARGETNAMESPACE);
            if(schemaNamespace != null && schemaNamespace.length() > 0) {
                // Since now we've discovered a namespace, we need to update xsd key
                // and store this schema in traversed schemas bucket
                schemaNamespace = fSymbolTable.addSymbol(schemaNamespace);
                desc.setTargetNamespace(schemaNamespace);
            }
            else {
                schemaNamespace = null;
            }
            grammar = findGrammar(desc, fNamespaceGrowth);
            String schemaId = XMLEntityManager.expandSystemId(is.getSystemId(), is.getBaseSystemId(), false);
            if (grammar != null) {
                // When namespace growth is enabled and a null location is provided we cannot tell
                // whether we've loaded this schema document before so we must assume that we haven't.
                if (!fNamespaceGrowth || (schemaId != null && grammar.getDocumentLocations().contains(schemaId))) {
                    return grammar; 
                }
            }

            XSDKey key = new XSDKey(schemaId, referType, schemaNamespace);
            fTraversed.put(key, schemaRoot);
            if (schemaId != null) {
            	fDoc2SystemId.put(schemaRoot, schemaId);
            }
        }

        // before constructing trees and traversing a schema, need to reset
        // all traversers and clear all registries
        prepareForTraverse();
        
        fRoot = constructTrees(schemaRoot, is.getSystemId(), desc, grammar != null);
        if (fRoot == null) {
            return null;
        }
        
        // second phase:  fill global registries.
        buildGlobalNameRegistries();
        
        // third phase:  call traversers
        ArrayList annotationInfo = fValidateAnnotations ? new ArrayList() : null;
        traverseSchemas(annotationInfo);
        
        // fourth phase: handle local element decls
        traverseLocalElements();
        
        // fifth phase:  handle Keyrefs
        resolveKeyRefs();
        
        // sixth phase:  validate attribute of non-schema namespaces
        // REVISIT: skip this for now. we really don't want to do it.
        //fAttributeChecker.checkNonSchemaAttributes(fGrammarBucket);
        
        // seventh phase:  store imported grammars
        // for all grammars with <import>s
        for (int i = fAllTNSs.size() - 1; i >= 0; i--) {
            // get its target namespace
            String tns = (String)fAllTNSs.elementAt(i);
            // get all namespaces it imports
            Vector ins = (Vector)fImportMap.get(tns);
            // get the grammar
            SchemaGrammar sg = fGrammarBucket.getGrammar(emptyString2Null(tns));
            if (sg == null)
                continue;
            SchemaGrammar isg;
            // for imported namespace
            int count = 0;
            for (int j = 0; j < ins.size(); j++) {
                // get imported grammar
                isg = fGrammarBucket.getGrammar((String)ins.elementAt(j));
                // reuse the same vector
                if (isg != null)
                    ins.setElementAt(isg, count++);
            }
            ins.setSize(count);
            // set the imported grammars
            sg.setImportedGrammars(ins);
        }
        
        /** validate annotations **/
        if (fValidateAnnotations && annotationInfo.size() > 0) {
            validateAnnotations(annotationInfo);
        }

        // and return.
        return fGrammarBucket.getGrammar(fRoot.fTargetNamespace);
    } // end parseSchema
    
    private void validateAnnotations(ArrayList annotationInfo) {
        if (fAnnotationValidator == null) {
            createAnnotationValidator();
        }
        final int size = annotationInfo.size();
        final XMLInputSource src = new XMLInputSource(null, null, null);
        fGrammarBucketAdapter.refreshGrammars(fGrammarBucket);
        for (int i = 0; i < size; i += 2) {
            src.setSystemId((String) annotationInfo.get(i));
            XSAnnotationInfo annotation = (XSAnnotationInfo) annotationInfo.get(i+1);
            while (annotation != null) {
                src.setCharacterStream(new StringReader(annotation.fAnnotation));
                try {
                    fAnnotationValidator.parse(src);
                }
                catch (IOException exc) {}
                annotation = annotation.next;
            }
        }
    }
    
    private void createAnnotationValidator() {
        fAnnotationValidator = new XML11Configuration();
        fGrammarBucketAdapter = new XSAnnotationGrammarPool();
        fAnnotationValidator.setFeature(VALIDATION, true);
        fAnnotationValidator.setFeature(XMLSCHEMA_VALIDATION, true);
        fAnnotationValidator.setProperty(XMLGRAMMAR_POOL, fGrammarBucketAdapter);
        /** Set error handler. **/
        XMLErrorHandler errorHandler = fErrorReporter.getErrorHandler();
        fAnnotationValidator.setProperty(ERROR_HANDLER, (errorHandler != null) ? errorHandler : new DefaultErrorHandler());
        /** Set locale. **/
        Locale locale = fErrorReporter.getLocale();
        fAnnotationValidator.setProperty(LOCALE, locale);
    }

    
Pull the grammar out of the bucket simply using
its TNS as a key
/**
     * Pull the grammar out of the bucket simply using
     * its TNS as a key
     */
    SchemaGrammar getGrammar(String tns) {
        return fGrammarBucket.getGrammar(tns);
    }
    
    
First try to find a grammar in the bucket, if failed, consult the
grammar pool. If a grammar is found in the pool, then add it (and all
imported ones) into the bucket.
/**
     * First try to find a grammar in the bucket, if failed, consult the
     * grammar pool. If a grammar is found in the pool, then add it (and all
     * imported ones) into the bucket.
     */
    protected SchemaGrammar findGrammar(XSDDescription desc, boolean ignoreConflict) {
        SchemaGrammar sg = fGrammarBucket.getGrammar(desc.getTargetNamespace());
        if (sg == null) {
            if (fGrammarPool != null) {
                sg = (SchemaGrammar)fGrammarPool.retrieveGrammar(desc);
                if (sg != null) {
                    // put this grammar into the bucket, along with grammars
                    // imported by it (directly or indirectly)
                    if (!fGrammarBucket.putGrammar(sg, true, ignoreConflict)) {
                        // REVISIT: a conflict between new grammar(s) and grammars
                        // in the bucket. What to do? A warning? An exception?
                        reportSchemaWarning("GrammarConflict", null, null);
                        sg = null;
                    }
                }
            }
        }
        return sg;
    }
    
    // may wish to have setter methods for ErrorHandler,
    // EntityResolver...
    
    private static final String[][] NS_ERROR_CODES = {
            {"src-include.2.1", "src-include.2.1"},
            {"src-redefine.3.1", "src-redefine.3.1"},
            {"src-import.3.1", "src-import.3.2"},
            null,
            {"TargetNamespace.1", "TargetNamespace.2"},
            {"TargetNamespace.1", "TargetNamespace.2"},
            {"TargetNamespace.1", "TargetNamespace.2"},
            {"TargetNamespace.1", "TargetNamespace.2"}
    };
    
    private static final String[] ELE_ERROR_CODES = {
            "src-include.1", "src-redefine.2", "src-import.2", "schema_reference.4",
            "schema_reference.4", "schema_reference.4", "schema_reference.4", "schema_reference.4"
    };
    
    // This method does several things:
    // It constructs an instance of an XSDocumentInfo object using the
    // schemaRoot node.  Then, for each <include>,
    // <redefine>, and <import> children, it attempts to resolve the
    // requested schema document, initiates a DOM parse, and calls
    // itself recursively on that document's root.  It also records in
    // the DependencyMap object what XSDocumentInfo objects its XSDocumentInfo
    // depends on.
    // It also makes sure the targetNamespace of the schema it was
    // called to parse is correct.
    protected XSDocumentInfo constructTrees(Element schemaRoot, String locationHint, XSDDescription desc, boolean nsCollision) {
        if (schemaRoot == null) return null;
        String callerTNS = desc.getTargetNamespace();
        short referType = desc.getContextType();
        
        XSDocumentInfo currSchemaInfo = null;
        try {
            // note that attributes are freed at end of traverseSchemas()
            currSchemaInfo = new XSDocumentInfo(schemaRoot, fAttributeChecker, fSymbolTable);
        } catch (XMLSchemaException se) {
            reportSchemaError(ELE_ERROR_CODES[referType],
                    new Object[]{locationHint},
					  schemaRoot);
            return null;
        }
        // targetNamespace="" is not valid, issue a warning, and ignore it
        if (currSchemaInfo.fTargetNamespace != null &&
                currSchemaInfo.fTargetNamespace.length() == 0) {
            reportSchemaWarning("EmptyTargetNamespace",
                    new Object[]{locationHint},
					schemaRoot);
            currSchemaInfo.fTargetNamespace = null;
        }
        
        if (callerTNS != null) {
            // the second index to the NS_ERROR_CODES array
            // if the caller/expected NS is not absent, we use the first column
            int secondIdx = 0;
            // for include and redefine
            if (referType == XSDDescription.CONTEXT_INCLUDE ||
                    referType == XSDDescription.CONTEXT_REDEFINE) {
                // if the referred document has no targetNamespace,
                // it's a chameleon schema
                if (currSchemaInfo.fTargetNamespace == null) {
                    currSchemaInfo.fTargetNamespace = callerTNS;
                    currSchemaInfo.fIsChameleonSchema = true;
                }
                // if the referred document has a target namespace differing
                // from the caller, it's an error
                else if (callerTNS != currSchemaInfo.fTargetNamespace) {
                    reportSchemaError(NS_ERROR_CODES[referType][secondIdx],
                            new Object [] {callerTNS, currSchemaInfo.fTargetNamespace},
							schemaRoot);
                    return null;
                }
            }
            // for instance and import, the two NS's must be the same
            else if (referType != XSDDescription.CONTEXT_PREPARSE && callerTNS != currSchemaInfo.fTargetNamespace) {
                reportSchemaError(NS_ERROR_CODES[referType][secondIdx],
                        new Object [] {callerTNS, currSchemaInfo.fTargetNamespace},
						schemaRoot);
                return null;
            }
        }
        // now there is no caller/expected NS, it's an error for the referred
        // document to have a target namespace, unless we are preparsing a schema
        else if (currSchemaInfo.fTargetNamespace != null) {
            // set the target namespace of the description
            if (referType == XSDDescription.CONTEXT_PREPARSE) {
                desc.setTargetNamespace(currSchemaInfo.fTargetNamespace);
                callerTNS = currSchemaInfo.fTargetNamespace;
            }
            else {
                // the second index to the NS_ERROR_CODES array
                // if the caller/expected NS is absent, we use the second column
                int secondIdx = 1;
                reportSchemaError(NS_ERROR_CODES[referType][secondIdx],
                        new Object [] {callerTNS, currSchemaInfo.fTargetNamespace},
						schemaRoot);
                return null;
            }
        }
        // the other cases (callerTNS == currSchemaInfo.fTargetNamespce == null)
        // are valid
        
        // a schema document can always access it's own target namespace
        currSchemaInfo.addAllowedNS(currSchemaInfo.fTargetNamespace);
        
        SchemaGrammar sg = null;

        // we have a namespace collision
        if (nsCollision) {
            SchemaGrammar sg2 = fGrammarBucket.getGrammar(currSchemaInfo.fTargetNamespace);
            if (sg2.isImmutable()) {
                sg = new SchemaGrammar(sg2);
                fGrammarBucket.putGrammar(sg);
                // update all the grammars in the bucket to point to the new grammar.
                updateImportListWith(sg);
            }
            else {
                sg = sg2;
            }

            // update import list of the new grammar
            updateImportListFor(sg);
        }
        else if (referType == XSDDescription.CONTEXT_INCLUDE ||
                referType == XSDDescription.CONTEXT_REDEFINE) {
            sg = fGrammarBucket.getGrammar(currSchemaInfo.fTargetNamespace);
        }
        else if(fHonourAllSchemaLocations && referType == XSDDescription.CONTEXT_IMPORT) {
            sg = findGrammar(desc, false);
            if(sg == null) {
                sg = new SchemaGrammar(currSchemaInfo.fTargetNamespace, desc.makeClone(), fSymbolTable);
                fGrammarBucket.putGrammar(sg);
            }
        }
        else {
            sg = new SchemaGrammar(currSchemaInfo.fTargetNamespace, desc.makeClone(), fSymbolTable);
            fGrammarBucket.putGrammar(sg);
        }

        // store the document and its location
        // REVISIT: don't expose the DOM tree
        sg.addDocument(null, (String)fDoc2SystemId.get(currSchemaInfo.fSchemaElement));
        
        fDoc2XSDocumentMap.put(schemaRoot, currSchemaInfo);
        Vector dependencies = new Vector();
        Element rootNode = schemaRoot;
        
        Element newSchemaRoot = null;
        for (Element child = DOMUtil.getFirstChildElement(rootNode);
        child != null;
        child = DOMUtil.getNextSiblingElement(child)) {
            String schemaNamespace=null;
            String schemaHint=null;
            String localName = DOMUtil.getLocalName(child);
            
            short refType = -1;
            boolean importCollision = false;
            
            if (localName.equals(SchemaSymbols.ELT_ANNOTATION))
                continue;
            else if (localName.equals(SchemaSymbols.ELT_IMPORT)) {
                refType = XSDDescription.CONTEXT_IMPORT;
                // have to handle some validation here too!
                // call XSAttributeChecker to fill in attrs
                Object[] importAttrs = fAttributeChecker.checkAttributes(child, true, currSchemaInfo);
                schemaHint = (String)importAttrs[XSAttributeChecker.ATTIDX_SCHEMALOCATION];
                schemaNamespace = (String)importAttrs[XSAttributeChecker.ATTIDX_NAMESPACE];
                if (schemaNamespace != null)
                    schemaNamespace = fSymbolTable.addSymbol(schemaNamespace);
                
                // check contents and process optional annotations
                Element importChild = DOMUtil.getFirstChildElement(child);
                if(importChild != null ) {
                    String importComponentType = DOMUtil.getLocalName(importChild);
                    if (importComponentType.equals(SchemaSymbols.ELT_ANNOTATION)) {
                        // promoting annotations to parent component
                        sg.addAnnotation(
                                fElementTraverser.traverseAnnotationDecl(importChild, importAttrs, true, currSchemaInfo));
                    } else {
                        reportSchemaError("s4s-elt-must-match.1", new Object [] {localName, "annotation?", importComponentType}, child);
                    }
                    if(DOMUtil.getNextSiblingElement(importChild) != null) {
                        reportSchemaError("s4s-elt-must-match.1", new Object [] {localName, "annotation?", DOMUtil.getLocalName(DOMUtil.getNextSiblingElement(importChild))}, child);
                    }
                }
                else {
                    String text = DOMUtil.getSyntheticAnnotation(child);
                    if (text != null) {
                        sg.addAnnotation(fElementTraverser.traverseSyntheticAnnotation(child, text, importAttrs, true, currSchemaInfo));
                    }
                }
                fAttributeChecker.returnAttrArray(importAttrs, currSchemaInfo);
                
                // a document can't import another document with the same namespace
                if (schemaNamespace == currSchemaInfo.fTargetNamespace) {
                    reportSchemaError(schemaNamespace != null ? 
                            "src-import.1.1" : "src-import.1.2", new Object [] {schemaNamespace}, child);
                    continue;
                }

                // if this namespace has not been imported by this document,
                //  then import if multiple imports support is enabled.
                if(currSchemaInfo.isAllowedNS(schemaNamespace)) {
                    if(!fHonourAllSchemaLocations && !fNamespaceGrowth)
                        continue;
                }
                else  {
                    currSchemaInfo.addAllowedNS(schemaNamespace);
                }
                // also record the fact that one namespace imports another one
                // convert null to ""
                String tns = null2EmptyString(currSchemaInfo.fTargetNamespace);
                // get all namespaces imported by this one
                Vector ins = (Vector)fImportMap.get(tns);
                // if no namespace was imported, create new Vector
                if (ins == null) {
                    // record that this one imports other(s)
                    fAllTNSs.addElement(tns);
                    ins = new Vector();
                    fImportMap.put(tns, ins);
                    ins.addElement(schemaNamespace);
                }
                else if (!ins.contains(schemaNamespace)){
                    ins.addElement(schemaNamespace);
                }

                fSchemaGrammarDescription.reset();
                fSchemaGrammarDescription.setContextType(XSDDescription.CONTEXT_IMPORT);
                fSchemaGrammarDescription.setBaseSystemId(doc2SystemId(schemaRoot));
                fSchemaGrammarDescription.setLiteralSystemId(schemaHint);
                fSchemaGrammarDescription.setLocationHints(new String[]{schemaHint});
                fSchemaGrammarDescription.setTargetNamespace(schemaNamespace);
                
                // if a grammar with the same namespace and location exists (or being
                // built), ignore this one (don't traverse it).
                SchemaGrammar isg = findGrammar(fSchemaGrammarDescription, fNamespaceGrowth);
                if (isg != null) {
                    if (fNamespaceGrowth) {
                        try {
                            if (isg.getDocumentLocations().contains(XMLEntityManager.expandSystemId(schemaHint, fSchemaGrammarDescription.getBaseSystemId(), false))) {
                                continue;
                            }
                            else {
                                importCollision = true;
                            }
                        } 
                        catch (MalformedURIException e) {
                        }
                    }
                    else if (!fHonourAllSchemaLocations || isExistingGrammar(fSchemaGrammarDescription, false)) {
                        continue;
                    }
                }
                //if ((!fHonourAllSchemaLocations && findGrammar(fSchemaGrammarDescription) != null) || isExistingGrammar(fSchemaGrammarDescription))
                //    continue;

                // If "findGrammar" returns a grammar, then this is not the
                // the first time we see a location for a given namespace.
                // Don't consult the location pair hashtable in this case,
                // otherwise the location will be ignored because it'll get
                // resolved to the same location as the first hint.
                newSchemaRoot = resolveSchema(fSchemaGrammarDescription, false, child, isg == null);
            }
            else if ((localName.equals(SchemaSymbols.ELT_INCLUDE)) ||
                    (localName.equals(SchemaSymbols.ELT_REDEFINE))) {
                // validation for redefine/include will be the same here; just
                // make sure TNS is right (don't care about redef contents
                // yet).
                Object[] includeAttrs = fAttributeChecker.checkAttributes(child, true, currSchemaInfo);
                schemaHint = (String)includeAttrs[XSAttributeChecker.ATTIDX_SCHEMALOCATION];
                // store the namespace decls of the redefine element
                if (localName.equals(SchemaSymbols.ELT_REDEFINE)) {
                    fRedefine2NSSupport.put(child, new SchemaNamespaceSupport(currSchemaInfo.fNamespaceSupport));
                }
                
                // check annotations.  Must do this here to avoid having to
                // re-parse attributes later
                if(localName.equals(SchemaSymbols.ELT_INCLUDE)) {
                    Element includeChild = DOMUtil.getFirstChildElement(child);
                    if(includeChild != null ) {
                        String includeComponentType = DOMUtil.getLocalName(includeChild);
                        if (includeComponentType.equals(SchemaSymbols.ELT_ANNOTATION)) {
                            // promoting annotations to parent component
                            sg.addAnnotation(
                                    fElementTraverser.traverseAnnotationDecl(includeChild, includeAttrs, true, currSchemaInfo));
                        } else {
                            reportSchemaError("s4s-elt-must-match.1", new Object [] {localName, "annotation?", includeComponentType}, child);
                        }
                        if(DOMUtil.getNextSiblingElement(includeChild) != null) {
                            reportSchemaError("s4s-elt-must-match.1", new Object [] {localName, "annotation?", DOMUtil.getLocalName(DOMUtil.getNextSiblingElement(includeChild))}, child);
                        }
                    }
                    else {
                        String text = DOMUtil.getSyntheticAnnotation(child);
                        if (text != null) {
                            sg.addAnnotation(fElementTraverser.traverseSyntheticAnnotation(child, text, includeAttrs, true, currSchemaInfo));
                        }
                    }
                }
                else {
                    for (Element redefinedChild = DOMUtil.getFirstChildElement(child);
                    redefinedChild != null;
                    redefinedChild = DOMUtil.getNextSiblingElement(redefinedChild)) {
                        String redefinedComponentType = DOMUtil.getLocalName(redefinedChild);
                        if (redefinedComponentType.equals(SchemaSymbols.ELT_ANNOTATION)) {
                            // promoting annotations to parent component
                            sg.addAnnotation(
                                    fElementTraverser.traverseAnnotationDecl(redefinedChild, includeAttrs, true, currSchemaInfo));
                            DOMUtil.setHidden(redefinedChild, fHiddenNodes);
                        }
                        else {
                            String text = DOMUtil.getSyntheticAnnotation(child);
                            if (text != null) {
                                sg.addAnnotation(fElementTraverser.traverseSyntheticAnnotation(child, text, includeAttrs, true, currSchemaInfo));
                            }
                        }
                        // catch all other content errors later
                    }
                }
                fAttributeChecker.returnAttrArray(includeAttrs, currSchemaInfo);
                // schemaLocation is required on <include> and <redefine>
                if (schemaHint == null) {
                    reportSchemaError("s4s-att-must-appear", new Object [] {
                            "<include> or <redefine>", "schemaLocation"},
                            child);
                }
                // pass the systemId of the current document as the base systemId
                boolean mustResolve = false;
                refType = XSDDescription.CONTEXT_INCLUDE;
                if(localName.equals(SchemaSymbols.ELT_REDEFINE)) {
                    mustResolve = nonAnnotationContent(child);
                    refType = XSDDescription.CONTEXT_REDEFINE;
                }
                fSchemaGrammarDescription.reset();
                fSchemaGrammarDescription.setContextType(refType);
                fSchemaGrammarDescription.setBaseSystemId(doc2SystemId(schemaRoot));
                fSchemaGrammarDescription.setLocationHints(new String[]{schemaHint});
                fSchemaGrammarDescription.setTargetNamespace(callerTNS);
                
                boolean alreadyTraversed = false;
                XMLInputSource schemaSource = resolveSchemaSource(fSchemaGrammarDescription, mustResolve, child, true);
                if (fNamespaceGrowth && refType == XSDDescription.CONTEXT_INCLUDE) {
                    try {
                        final String schemaId = XMLEntityManager.expandSystemId(schemaSource.getSystemId(), schemaSource.getBaseSystemId(), false);
                        alreadyTraversed = sg.getDocumentLocations().contains(schemaId);
                    }
                    catch(MalformedURIException e) {
                        
                    }
                }

                if (!alreadyTraversed) {
                    newSchemaRoot = resolveSchema(schemaSource, fSchemaGrammarDescription, mustResolve, child);
                    schemaNamespace = currSchemaInfo.fTargetNamespace;
                }
                else {
                    fLastSchemaWasDuplicate = true;
                }
            }
            else {
                // no more possibility of schema references in well-formed
                // schema...
                break;
            }
            
            // If the schema is duplicate, we needn't call constructTrees() again.
            // To handle mutual <include>s
            XSDocumentInfo newSchemaInfo = null;
            if (fLastSchemaWasDuplicate) {
                newSchemaInfo = newSchemaRoot == null ? null : (XSDocumentInfo)fDoc2XSDocumentMap.get(newSchemaRoot);
            }
            else {
               	newSchemaInfo = constructTrees(newSchemaRoot, schemaHint, fSchemaGrammarDescription, importCollision);
            }

            if (localName.equals(SchemaSymbols.ELT_REDEFINE) &&
                    newSchemaInfo != null) {
                // must record which schema we're redefining so that we can
                // rename the right things later!
                fRedefine2XSDMap.put(child, newSchemaInfo);
            }
            if (newSchemaRoot != null) {
                if (newSchemaInfo != null)
                    dependencies.addElement(newSchemaInfo);
                newSchemaRoot = null;
            }
        }
        
        fDependencyMap.put(currSchemaInfo, dependencies);
        return currSchemaInfo;
    } // end constructTrees
    
    private boolean isExistingGrammar(XSDDescription desc, boolean ignoreConflict) {
        SchemaGrammar sg = fGrammarBucket.getGrammar(desc.getTargetNamespace());
        if (sg == null) {
            return findGrammar(desc, ignoreConflict) != null;
        }
        else if (sg.isImmutable()) {
            return true;
        }
        else {
            try {
                return sg.getDocumentLocations().contains(XMLEntityManager.expandSystemId(desc.getLiteralSystemId(), desc.getBaseSystemId(), false));
            } 
            catch (MalformedURIException e) {
                return false;
            }
        }
    }

    
Namespace growth
Go through the import list of a given grammar and for each imported
grammar, check to see if the grammar bucket has a newer version.
If a new instance is found, we update the import list with the
newer version.
/**
     * Namespace growth
     * 
     * Go through the import list of a given grammar and for each imported
     * grammar, check to see if the grammar bucket has a newer version.
     * If a new instance is found, we update the import list with the
     * newer version.
     */
    private void updateImportListFor(SchemaGrammar grammar) {
        Vector importedGrammars = grammar.getImportedGrammars();
        if (importedGrammars != null) {
            for (int i=0; i<importedGrammars.size(); i++) {
                SchemaGrammar isg1 = (SchemaGrammar) importedGrammars.elementAt(i);
                SchemaGrammar isg2 = fGrammarBucket.getGrammar(isg1.getTargetNamespace());
                if (isg2 != null && isg1 != isg2) {
                    importedGrammars.set(i, isg2);
                }
            }
        }
    }

    
Namespace growth
Go throuth the grammar bucket, and for each grammar in the bucket
check the import list. If there exists a grammar in import list
that has the same namespace as newGrammar, but a different instance,
then update the import list and replace the old grammar instance with
the new one
/**
     * Namespace growth
     * 
     * Go throuth the grammar bucket, and for each grammar in the bucket
     * check the import list. If there exists a grammar in import list
     * that has the same namespace as newGrammar, but a different instance,
     * then update the import list and replace the old grammar instance with
     * the new one
     */
    private void updateImportListWith(SchemaGrammar newGrammar) {
        SchemaGrammar[] schemaGrammars = fGrammarBucket.getGrammars();
        for (int i = 0; i < schemaGrammars.length; ++i) {
            SchemaGrammar sg = schemaGrammars[i];
            if (sg != newGrammar) {
                Vector importedGrammars = sg.getImportedGrammars();
                if (importedGrammars != null) {
                    for (int j=0; j<importedGrammars.size(); j++) {
                        SchemaGrammar isg = (SchemaGrammar) importedGrammars.elementAt(j);
                        if (null2EmptyString(isg.getTargetNamespace()).equals(null2EmptyString(newGrammar.getTargetNamespace()))) {
                            if (isg != newGrammar) {
                                importedGrammars.set(j, newGrammar);
                            }
                            break;
                        }
                    }
                }
            }
        }
    }

    // This method builds registries for all globally-referenceable
    // names.  A registry will be built for each symbol space defined
    // by the spec.  It is also this method's job to rename redefined
    // components, and to record which components redefine others (so
    // that implicit redefinitions of groups and attributeGroups can be handled).
    protected void buildGlobalNameRegistries() {
        

        // Starting with fRoot, we examine each child of the schema
        // element.  Skipping all imports and includes, we record the names
        // of all other global components (and children of <redefine>).  We
        // also put <redefine> names in a registry that we look through in
        // case something needs renaming.  Once we're done with a schema we
        // set its Document node to hidden so that we don't try to traverse
        // it again; then we look to its Dependency map entry.  We keep a
        // stack of schemas that we haven't yet finished processing; this
        // is a depth-first traversal.
            
        Stack schemasToProcess = new Stack();
        schemasToProcess.push(fRoot);
       
        while (!schemasToProcess.empty()) {            
            XSDocumentInfo currSchemaDoc =
                (XSDocumentInfo)schemasToProcess.pop();
            Element currDoc = currSchemaDoc.fSchemaElement; 
            if(DOMUtil.isHidden(currDoc, fHiddenNodes)){
                // must have processed this already!
                continue;
            }

            Element currRoot = currDoc;
            // process this schema's global decls
            boolean dependenciesCanOccur = true;
            for (Element globalComp =
                DOMUtil.getFirstChildElement(currRoot);
            globalComp != null;
            globalComp = DOMUtil.getNextSiblingElement(globalComp)) {
                // this loop makes sure the <schema> element ordering is
                // also valid.
                if (DOMUtil.getLocalName(globalComp).equals(SchemaSymbols.ELT_ANNOTATION)) {
                    //skip it; traverse it later
                    continue;
                }
                else if (DOMUtil.getLocalName(globalComp).equals(SchemaSymbols.ELT_INCLUDE) ||
                        DOMUtil.getLocalName(globalComp).equals(SchemaSymbols.ELT_IMPORT)) {
                    if (!dependenciesCanOccur) {
                        reportSchemaError("s4s-elt-invalid-content.3", new Object [] {DOMUtil.getLocalName(globalComp)}, globalComp);
                    }
                    DOMUtil.setHidden(globalComp, fHiddenNodes);
                }
                else if (DOMUtil.getLocalName(globalComp).equals(SchemaSymbols.ELT_REDEFINE)) {
                    if (!dependenciesCanOccur) {
                        reportSchemaError("s4s-elt-invalid-content.3", new Object [] {DOMUtil.getLocalName(globalComp)}, globalComp);
                    }
                    for (Element redefineComp = DOMUtil.getFirstChildElement(globalComp);
                    redefineComp != null;
                    redefineComp = DOMUtil.getNextSiblingElement(redefineComp)) {
                        String lName = DOMUtil.getAttrValue(redefineComp, SchemaSymbols.ATT_NAME);
                        if (lName.length() == 0) // an error we'll catch later
                            continue;
                        String qName = currSchemaDoc.fTargetNamespace == null ?
                                ","+lName:
                                    currSchemaDoc.fTargetNamespace +","+lName;
                        qName = XMLChar.trim(qName);
                        String componentType = DOMUtil.getLocalName(redefineComp);
                        if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTEGROUP)) {
                            checkForDuplicateNames(qName, ATTRIBUTEGROUP_TYPE, fUnparsedAttributeGroupRegistry, fUnparsedAttributeGroupRegistrySub, redefineComp, currSchemaDoc);
                            // the check will have changed our name;
                            String targetLName = DOMUtil.getAttrValue(redefineComp, SchemaSymbols.ATT_NAME)+REDEF_IDENTIFIER;
                            // and all we need to do is error-check+rename our kkids:
                            renameRedefiningComponents(currSchemaDoc, redefineComp, SchemaSymbols.ELT_ATTRIBUTEGROUP,
                                    lName, targetLName);
                        }
                        else if ((componentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) ||
                                (componentType.equals(SchemaSymbols.ELT_SIMPLETYPE))) {
                            checkForDuplicateNames(qName, TYPEDECL_TYPE, fUnparsedTypeRegistry, fUnparsedTypeRegistrySub, redefineComp, currSchemaDoc);
                            // the check will have changed our name;
                            String targetLName = DOMUtil.getAttrValue(redefineComp, SchemaSymbols.ATT_NAME) + REDEF_IDENTIFIER;
                            // and all we need to do is error-check+rename our kkids:
                            if (componentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) {
                                renameRedefiningComponents(currSchemaDoc, redefineComp, SchemaSymbols.ELT_COMPLEXTYPE,
                                        lName, targetLName);
                            }
                            else { // must be simpleType
                                renameRedefiningComponents(currSchemaDoc, redefineComp, SchemaSymbols.ELT_SIMPLETYPE,
                                        lName, targetLName);
                            }
                        }
                        else if (componentType.equals(SchemaSymbols.ELT_GROUP)) {
                            checkForDuplicateNames(qName, GROUP_TYPE, fUnparsedGroupRegistry, fUnparsedGroupRegistrySub, redefineComp, currSchemaDoc);
                            // the check will have changed our name;
                            String targetLName = DOMUtil.getAttrValue(redefineComp, SchemaSymbols.ATT_NAME)+REDEF_IDENTIFIER;
                            // and all we need to do is error-check+rename our kids:
                            renameRedefiningComponents(currSchemaDoc, redefineComp, SchemaSymbols.ELT_GROUP,
                                    lName, targetLName);
                        }
                    } // end march through <redefine> children
                    // and now set as traversed
                    //DOMUtil.setHidden(globalComp);
                }
                else {
                    dependenciesCanOccur = false;
                    String lName = DOMUtil.getAttrValue(globalComp, SchemaSymbols.ATT_NAME);
                    if (lName.length() == 0) // an error we'll catch later
                        continue;
                    String qName = currSchemaDoc.fTargetNamespace == null?
                            ","+lName:
                                currSchemaDoc.fTargetNamespace +","+lName;
                    qName = XMLChar.trim(qName);
                    String componentType = DOMUtil.getLocalName(globalComp);

                    if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTE)) {
                        checkForDuplicateNames(qName, ATTRIBUTE_TYPE, fUnparsedAttributeRegistry, fUnparsedAttributeRegistrySub, globalComp, currSchemaDoc);
                    }
                    else if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTEGROUP)) {
                        checkForDuplicateNames(qName, ATTRIBUTEGROUP_TYPE, fUnparsedAttributeGroupRegistry, fUnparsedAttributeGroupRegistrySub, globalComp, currSchemaDoc);
                    }
                    else if ((componentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) ||
                            (componentType.equals(SchemaSymbols.ELT_SIMPLETYPE))) {
                        checkForDuplicateNames(qName, TYPEDECL_TYPE, fUnparsedTypeRegistry, fUnparsedTypeRegistrySub, globalComp, currSchemaDoc);
                    }
                    else if (componentType.equals(SchemaSymbols.ELT_ELEMENT)) {
                        checkForDuplicateNames(qName, ELEMENT_TYPE, fUnparsedElementRegistry, fUnparsedElementRegistrySub, globalComp, currSchemaDoc);
                    }
                    else if (componentType.equals(SchemaSymbols.ELT_GROUP)) {
                        checkForDuplicateNames(qName, GROUP_TYPE, fUnparsedGroupRegistry, fUnparsedGroupRegistrySub, globalComp, currSchemaDoc);
                    }
                    else if (componentType.equals(SchemaSymbols.ELT_NOTATION)) {
                        checkForDuplicateNames(qName, NOTATION_TYPE, fUnparsedNotationRegistry, fUnparsedNotationRegistrySub, globalComp, currSchemaDoc);
                    }
                }
            } // end for
            
            // now we're done with this one!
           	DOMUtil.setHidden(currDoc, fHiddenNodes);
            // now add the schemas this guy depends on
            Vector currSchemaDepends = (Vector)fDependencyMap.get(currSchemaDoc);
            for (int i = 0; i < currSchemaDepends.size(); i++) {
                schemasToProcess.push(currSchemaDepends.elementAt(i));
            }
        } // while

    } // end buildGlobalNameRegistries
    
    // Beginning at the first schema processing was requested for
    // (fRoot), this method
    // examines each child (global schema information item) of each
    // schema document (and of each <redefine> element)
    // corresponding to an XSDocumentInfo object.  If the
    // readOnly field on that node has not been set, it calls an
    // appropriate traverser to traverse it.  Once all global decls in
    // an XSDocumentInfo object have been traversed, it marks that object
    // as traversed (or hidden) in order to avoid infinite loops.  It completes
    // when it has visited all XSDocumentInfo objects in the
    // DependencyMap and marked them as traversed.
    protected void traverseSchemas(ArrayList annotationInfo) {
        // the process here is very similar to that in
        // buildGlobalRegistries, except we can't set our schemas as
        // hidden for a second time; so make them all visible again
        // first!
        setSchemasVisible(fRoot);
        Stack schemasToProcess = new Stack();
        schemasToProcess.push(fRoot);
        while (!schemasToProcess.empty()) {
            XSDocumentInfo currSchemaDoc =
                (XSDocumentInfo)schemasToProcess.pop();
            Element currDoc = currSchemaDoc.fSchemaElement;
       
            SchemaGrammar currSG = fGrammarBucket.getGrammar(currSchemaDoc.fTargetNamespace);

            if(DOMUtil.isHidden(currDoc, fHiddenNodes)) {
                // must have processed this already!
                continue;
            }
            Element currRoot = currDoc;
            boolean sawAnnotation = false;
            // traverse this schema's global decls
            for (Element globalComp =
                DOMUtil.getFirstVisibleChildElement(currRoot, fHiddenNodes);
            globalComp != null;
            globalComp = DOMUtil.getNextVisibleSiblingElement(globalComp, fHiddenNodes)) {
                DOMUtil.setHidden(globalComp, fHiddenNodes); 
                String componentType = DOMUtil.getLocalName(globalComp);
                // includes and imports will not show up here!
                if (DOMUtil.getLocalName(globalComp).equals(SchemaSymbols.ELT_REDEFINE)) {
                    // use the namespace decls for the redefine, instead of for the parent <schema>
                    currSchemaDoc.backupNSSupport((SchemaNamespaceSupport)fRedefine2NSSupport.get(globalComp));
                    for (Element redefinedComp = DOMUtil.getFirstVisibleChildElement(globalComp, fHiddenNodes);
                    redefinedComp != null;
                    redefinedComp = DOMUtil.getNextVisibleSiblingElement(redefinedComp, fHiddenNodes)) {
                        String redefinedComponentType = DOMUtil.getLocalName(redefinedComp);
                        DOMUtil.setHidden(redefinedComp, fHiddenNodes);
                        if (redefinedComponentType.equals(SchemaSymbols.ELT_ATTRIBUTEGROUP)) {
                            fAttributeGroupTraverser.traverseGlobal(redefinedComp, currSchemaDoc, currSG);
                        }
                        else if (redefinedComponentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) {
                            fComplexTypeTraverser.traverseGlobal(redefinedComp, currSchemaDoc, currSG);
                        }
                        else if (redefinedComponentType.equals(SchemaSymbols.ELT_GROUP)) {
                            fGroupTraverser.traverseGlobal(redefinedComp, currSchemaDoc, currSG);
                        }
                        else if (redefinedComponentType.equals(SchemaSymbols.ELT_SIMPLETYPE)) {
                            fSimpleTypeTraverser.traverseGlobal(redefinedComp, currSchemaDoc, currSG);
                        }
                        // annotations will have been processed already; this is now
                        // unnecessary
                        //else if (redefinedComponentType.equals(SchemaSymbols.ELT_ANNOTATION)) {
                        //    fElementTraverser.traverseAnnotationDecl(redefinedComp, null, true, currSchemaDoc);
                        //}
                        else {
                            reportSchemaError("s4s-elt-must-match.1", new Object [] {DOMUtil.getLocalName(globalComp), "(annotation | (simpleType | complexType | group | attributeGroup))*", redefinedComponentType}, redefinedComp);
                        }
                    } // end march through <redefine> children
                    currSchemaDoc.restoreNSSupport();
                }
                else if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTE)) {
                    fAttributeTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTEGROUP)) {
                    fAttributeGroupTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) {
                    fComplexTypeTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_ELEMENT)) {
                    fElementTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_GROUP)) {
                    fGroupTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_NOTATION)) {
                    fNotationTraverser.traverse(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_SIMPLETYPE)) {
                    fSimpleTypeTraverser.traverseGlobal(globalComp, currSchemaDoc, currSG);
                }
                else if (componentType.equals(SchemaSymbols.ELT_ANNOTATION)) {
                    currSG.addAnnotation(fElementTraverser.traverseAnnotationDecl(globalComp, currSchemaDoc.getSchemaAttrs(), true, currSchemaDoc));
                    sawAnnotation = true;
                }
                else {
                    reportSchemaError("s4s-elt-invalid-content.1", new Object [] {SchemaSymbols.ELT_SCHEMA, DOMUtil.getLocalName(globalComp)}, globalComp);
                }
            } // end for
            
            if (!sawAnnotation) {
                String text = DOMUtil.getSyntheticAnnotation(currRoot);
                if (text != null) {
                    currSG.addAnnotation(fElementTraverser.traverseSyntheticAnnotation(currRoot, text, currSchemaDoc.getSchemaAttrs(), true, currSchemaDoc));
                }
            }
            
            /** Collect annotation information for validation. **/
            if (annotationInfo != null) {
                XSAnnotationInfo info = currSchemaDoc.getAnnotations();
                /** Only add annotations to the list if there were any in this document. **/
                if (info != null) {
                    annotationInfo.add(doc2SystemId(currDoc));
                    annotationInfo.add(info);
                }
            }
            // now we're done with this one!
            currSchemaDoc.returnSchemaAttrs();
            DOMUtil.setHidden(currDoc, fHiddenNodes);

            // now add the schemas this guy depends on
            Vector currSchemaDepends = (Vector)fDependencyMap.get(currSchemaDoc);
            for (int i = 0; i < currSchemaDepends.size(); i++) {
                schemasToProcess.push(currSchemaDepends.elementAt(i));
            }
        } // while
    } // end traverseSchemas
    
    // store whether we have reported an error about that no grammar
    // is found for the given namespace uri
    private Vector fReportedTNS = null;
    // check whether we need to report an error against the given uri.
    // if we have reported an error, then we don't need to report again;
    // otherwise we reported the error, and remember this fact.
    private final boolean needReportTNSError(String uri) {
        if (fReportedTNS == null)
            fReportedTNS = new Vector();
        else if (fReportedTNS.contains(uri))
            return false;
        fReportedTNS.addElement(uri);
        return true;
    }
    
    private static final String[] COMP_TYPE = {
            null,               // index 0
            "attribute declaration",
            "attribute group",
            "element declaration",
            "group",
            "identity constraint",
            "notation",
            "type definition",
    };
    
    private static final String[] CIRCULAR_CODES = {
            "Internal-Error",
            "Internal-Error",
            "src-attribute_group.3",
            "e-props-correct.6",
            "mg-props-correct.2",
            "Internal-Error",
            "Internal-Error",
            "st-props-correct.2",       //or ct-props-correct.3
    };

    // add a global attribute decl from a current schema load (only if no existing decl is found)
    void addGlobalAttributeDecl(XSAttributeDecl decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalAttrDecls.get(declKey) == null) {
            fGlobalAttrDecls.put(declKey, decl);
        }
    }

    // add a global attribute group decl from a current schema load (only if no existing decl is found)
    void addGlobalAttributeGroupDecl(XSAttributeGroupDecl decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalAttrGrpDecls.get(declKey) == null) {
            fGlobalAttrGrpDecls.put(declKey, decl);
        }
    }

    // add a global element decl from a current schema load (only if no existing decl is found)
    void addGlobalElementDecl(XSElementDecl decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalElemDecls.get(declKey) == null) {
            fGlobalElemDecls.put(declKey, decl);
        }
    }

    // add a global group decl from a current schema load (only if no existing decl is found)
    void addGlobalGroupDecl(XSGroupDecl decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalGroupDecls.get(declKey) == null) {
            fGlobalGroupDecls.put(declKey, decl);
        }
    }

    // add a global notation decl from a current schema load (only if no existing decl is found)
    void addGlobalNotationDecl(XSNotationDecl decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalNotationDecls.get(declKey) == null) {
            fGlobalNotationDecls.put(declKey, decl);
        }
    }

    // add a global type decl from a current schema load (only if no existing decl is found)
    void addGlobalTypeDecl(XSTypeDefinition decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getName() : namespace + "," + decl.getName();

        if (fGlobalTypeDecls.get(declKey) == null) {
            fGlobalTypeDecls.put(declKey, decl);
        }
    }

    // add a identity constraint decl from a current schema load (only if no existing decl is found)
    void addIDConstraintDecl(IdentityConstraint decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getIdentityConstraintName() : namespace + "," + decl.getIdentityConstraintName();

        if (fGlobalIDConstraintDecls.get(declKey) == null) {
            fGlobalIDConstraintDecls.put(declKey, decl);
        }
    }

    private XSAttributeDecl getGlobalAttributeDecl(String declKey) {
        return (XSAttributeDecl)fGlobalAttrDecls.get(declKey);
    }

    private XSAttributeGroupDecl getGlobalAttributeGroupDecl(String declKey) {
        return (XSAttributeGroupDecl)fGlobalAttrGrpDecls.get(declKey);
    }

    private XSElementDecl getGlobalElementDecl(String declKey) {
        return (XSElementDecl)fGlobalElemDecls.get(declKey);
    }

    private XSGroupDecl getGlobalGroupDecl(String declKey) {
        return (XSGroupDecl)fGlobalGroupDecls.get(declKey);
    }

    private XSNotationDecl getGlobalNotationDecl(String declKey) {
        return (XSNotationDecl)fGlobalNotationDecls.get(declKey);
    }

    private XSTypeDefinition getGlobalTypeDecl(String declKey) {
        return (XSTypeDefinition)fGlobalTypeDecls.get(declKey);
    }

    private IdentityConstraint getIDConstraintDecl(String declKey) {
        return (IdentityConstraint)fGlobalIDConstraintDecls.get(declKey);
    }

    // since it is forbidden for traversers to talk to each other
    // directly (except wen a traverser encounters a local declaration),
    // this provides a generic means for a traverser to call
    // for the traversal of some declaration.  An XSDocumentInfo is
    // required because the XSDocumentInfo that the traverser is traversing
    // may bear no relation to the one the handler is operating on.
    // This method will:
    // 1.  See if a global definition matching declToTraverse exists;
    // 2. if so, determine if there is a path from currSchema to the
    // schema document where declToTraverse lives (i.e., do a lookup
    // in DependencyMap);
    // 3. depending on declType (which will be relevant to step 1 as
    // well), call the appropriate traverser with the appropriate
    // XSDocumentInfo object.
    // This method returns whatever the traverser it called returned;
    // this will be an Object of some kind
    // that lives in the Grammar.
    protected Object getGlobalDecl(XSDocumentInfo currSchema,
            int declType,
            QName declToTraverse,
            Element elmNode) {

        if (DEBUG_NODE_POOL) {
            System.out.println("TRAVERSE_GL: "+declToTraverse.toString());
        }

        // from the schema spec, all built-in types are present in all schemas,
        // so if the requested component is a type, and could be found in the
        // default schema grammar, we should return that type.
        // otherwise (since we would support user-defined schema grammar) we'll
        // use the normal way to get the decl
        if (declToTraverse.uri != null &&
                declToTraverse.uri == SchemaSymbols.URI_SCHEMAFORSCHEMA) {
            if (declType == TYPEDECL_TYPE) {
                Object retObj = SchemaGrammar.SG_SchemaNS.getGlobalTypeDecl(declToTraverse.localpart);
                if (retObj != null)
                    return retObj;
            }
        }

        // now check whether this document can access the requsted namespace
        if (!currSchema.isAllowedNS(declToTraverse.uri)) {
            // cannot get to this schema from the one containing the requesting decl
            if (currSchema.needReportTNSError(declToTraverse.uri)) {
                String code = declToTraverse.uri == null ? "src-resolve.4.1" : "src-resolve.4.2";
                reportSchemaError(code, new Object[]{fDoc2SystemId.get(currSchema.fSchemaElement), declToTraverse.uri, declToTraverse.rawname}, elmNode);
            }
            // Recover and continue to look for the component.
            // return null;
        }

        // check whether there is grammar for the requested namespace
        SchemaGrammar sGrammar = fGrammarBucket.getGrammar(declToTraverse.uri);
        if (sGrammar == null) {
            if (needReportTNSError(declToTraverse.uri))
                reportSchemaError("src-resolve", new Object[]{declToTraverse.rawname, COMP_TYPE[declType]}, elmNode);
            return null;
        }

        // if there is such grammar, check whether the requested component is in the grammar
        Object retObj = getGlobalDeclFromGrammar(sGrammar, declType, declToTraverse.localpart);
        String declKey = declToTraverse.uri == null? ","+declToTraverse.localpart:
            declToTraverse.uri+","+declToTraverse.localpart;
        
        // if the component is parsed, return it
        if (!fTolerateDuplicates) {
            if (retObj != null) {
                return retObj;
            }
        }
        else {
            Object retObj2 = getGlobalDecl(declKey, declType);
            if (retObj2 != null) {
                return retObj2;
            }
        }

        XSDocumentInfo schemaWithDecl = null;
        Element decl = null;
        XSDocumentInfo declDoc = null;

        // the component is not parsed, try to find a DOM element for it
        switch (declType) {
        case ATTRIBUTE_TYPE :
            decl = (Element)fUnparsedAttributeRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedAttributeRegistrySub.get(declKey);
            break;
        case ATTRIBUTEGROUP_TYPE :
            decl = (Element)fUnparsedAttributeGroupRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedAttributeGroupRegistrySub.get(declKey);
            break;
        case ELEMENT_TYPE :
            decl = (Element)fUnparsedElementRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedElementRegistrySub.get(declKey);
            break;
        case GROUP_TYPE :
            decl = (Element)fUnparsedGroupRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedGroupRegistrySub.get(declKey);
            break;
        case IDENTITYCONSTRAINT_TYPE :
            decl = (Element)fUnparsedIdentityConstraintRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedIdentityConstraintRegistrySub.get(declKey);
            break;
        case NOTATION_TYPE :
            decl = (Element)fUnparsedNotationRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedNotationRegistrySub.get(declKey);
            break;
        case TYPEDECL_TYPE :
            decl = (Element)fUnparsedTypeRegistry.get(declKey);
            declDoc = (XSDocumentInfo)fUnparsedTypeRegistrySub.get(declKey);
            break;
        default:
            reportSchemaError("Internal-Error", new Object [] {"XSDHandler asked to locate component of type " + declType + "; it does not recognize this type!"}, elmNode);
        }

        // no DOM element found, so the component can't be located
        if (decl == null) {
            if (retObj == null) {
                reportSchemaError("src-resolve", new Object[]{declToTraverse.rawname, COMP_TYPE[declType]}, elmNode);
            }
            return retObj;
        }

        // get the schema doc containing the component to be parsed
        // it should always return non-null value, but since null-checking
        // comes for free, let's be safe and check again
        schemaWithDecl = findXSDocumentForDecl(currSchema, decl, declDoc);
        if (schemaWithDecl == null) {
            // cannot get to this schema from the one containing the requesting decl
            if (retObj == null) {
                String code = declToTraverse.uri == null ? "src-resolve.4.1" : "src-resolve.4.2";
                reportSchemaError(code, new Object[]{fDoc2SystemId.get(currSchema.fSchemaElement), declToTraverse.uri, declToTraverse.rawname}, elmNode);
            }
            return retObj;
        }

        // a component is hidden, meaning either it's traversed, or being traversed.
        // but we didn't find it in the grammar, so it's the latter case, and
        // a circular reference. error!
        if (DOMUtil.isHidden(decl, fHiddenNodes)) {
            if (retObj == null) {
                String code = CIRCULAR_CODES[declType];
                if (declType == TYPEDECL_TYPE) {
                    if (SchemaSymbols.ELT_COMPLEXTYPE.equals(DOMUtil.getLocalName(decl))) {
                        code = "ct-props-correct.3";
                    }
                }
                // decl must not be null if we're here...
                reportSchemaError(code, new Object [] {declToTraverse.prefix+":"+declToTraverse.localpart}, elmNode);
            }
            return retObj;
        }

        return traverseGlobalDecl(declType, decl, schemaWithDecl, sGrammar);
    } // getGlobalDecl(XSDocumentInfo, int, QName):  Object

    // If we are tolerating duplicate declarations and allowing namespace growth
    // use the declaration from the current schema load (if it exists)
    protected Object getGlobalDecl(String declKey, int declType) {
        Object retObj = null;

        switch (declType) {
        case ATTRIBUTE_TYPE :
            retObj = getGlobalAttributeDecl(declKey);
            break;
        case ATTRIBUTEGROUP_TYPE :
            retObj = getGlobalAttributeGroupDecl(declKey);
            break;
        case ELEMENT_TYPE :
            retObj = getGlobalElementDecl(declKey);
            break;
        case GROUP_TYPE :
            retObj = getGlobalGroupDecl(declKey);
            break;
        case IDENTITYCONSTRAINT_TYPE :
            retObj = getIDConstraintDecl(declKey);
            break;
        case NOTATION_TYPE :
            retObj = getGlobalNotationDecl(declKey);
            break;
        case TYPEDECL_TYPE :
            retObj = getGlobalTypeDecl(declKey);
            break;
        }

        return retObj;
    }

    protected Object getGlobalDeclFromGrammar(SchemaGrammar sGrammar, int declType, String localpart) {
        Object retObj = null;

        switch (declType) {
        case ATTRIBUTE_TYPE :
            retObj = sGrammar.getGlobalAttributeDecl(localpart);
            break;
        case ATTRIBUTEGROUP_TYPE :
            retObj = sGrammar.getGlobalAttributeGroupDecl(localpart);
            break;
        case ELEMENT_TYPE :
            retObj = sGrammar.getGlobalElementDecl(localpart);
            break;
        case GROUP_TYPE :
            retObj = sGrammar.getGlobalGroupDecl(localpart);
            break;
        case IDENTITYCONSTRAINT_TYPE :
            retObj = sGrammar.getIDConstraintDecl(localpart);
            break;
        case NOTATION_TYPE :
            retObj = sGrammar.getGlobalNotationDecl(localpart);
            break;
        case TYPEDECL_TYPE :
            retObj = sGrammar.getGlobalTypeDecl(localpart);
            break;
        }

        return retObj;
    }

    protected Object getGlobalDeclFromGrammar(SchemaGrammar sGrammar, int declType, String localpart, String schemaLoc) {
        Object retObj = null;

        switch (declType) {
        case ATTRIBUTE_TYPE :
            retObj = sGrammar.getGlobalAttributeDecl(localpart, schemaLoc);
            break;
        case ATTRIBUTEGROUP_TYPE :
            retObj = sGrammar.getGlobalAttributeGroupDecl(localpart, schemaLoc);
            break;
        case ELEMENT_TYPE :
            retObj = sGrammar.getGlobalElementDecl(localpart, schemaLoc);
            break;
        case GROUP_TYPE :
            retObj = sGrammar.getGlobalGroupDecl(localpart, schemaLoc);
            break;
        case IDENTITYCONSTRAINT_TYPE :
            retObj = sGrammar.getIDConstraintDecl(localpart, schemaLoc);
            break;
        case NOTATION_TYPE :
            retObj = sGrammar.getGlobalNotationDecl(localpart, schemaLoc);
            break;
        case TYPEDECL_TYPE :
            retObj = sGrammar.getGlobalTypeDecl(localpart, schemaLoc);
            break;
        }

        return retObj;
    }

    protected Object traverseGlobalDecl(int declType, Element decl, XSDocumentInfo schemaDoc, SchemaGrammar grammar) {
        Object retObj = null;

        DOMUtil.setHidden(decl, fHiddenNodes);
        SchemaNamespaceSupport nsSupport = null;
        // if the parent is <redefine> use the namespace delcs for it.
        Element parent = DOMUtil.getParent(decl);
        if (DOMUtil.getLocalName(parent).equals(SchemaSymbols.ELT_REDEFINE))
            nsSupport = (SchemaNamespaceSupport)fRedefine2NSSupport.get(parent);
        // back up the current SchemaNamespaceSupport, because we need to provide
        // a fresh one to the traverseGlobal methods.
        schemaDoc.backupNSSupport(nsSupport);

        // traverse the referenced global component
        switch (declType) {
        case TYPEDECL_TYPE :
            if (DOMUtil.getLocalName(decl).equals(SchemaSymbols.ELT_COMPLEXTYPE)) {
                retObj = fComplexTypeTraverser.traverseGlobal(decl, schemaDoc, grammar);
            }
            else {
                retObj = fSimpleTypeTraverser.traverseGlobal(decl, schemaDoc, grammar);
            }
            break;
        case ATTRIBUTE_TYPE :
            retObj = fAttributeTraverser.traverseGlobal(decl, schemaDoc, grammar);
            break;            
        case ELEMENT_TYPE :
            retObj = fElementTraverser.traverseGlobal(decl, schemaDoc, grammar);
            break;
        case ATTRIBUTEGROUP_TYPE :
            retObj = fAttributeGroupTraverser.traverseGlobal(decl, schemaDoc, grammar);
            break;
        case GROUP_TYPE :
            retObj = fGroupTraverser.traverseGlobal(decl, schemaDoc, grammar);
            break;
        case NOTATION_TYPE :
            retObj = fNotationTraverser.traverse(decl, schemaDoc, grammar);
            break;
        case IDENTITYCONSTRAINT_TYPE :
            // identity constraints should have been parsed already...
            // we should never get here
            break;            
        }

        // restore the previous SchemaNamespaceSupport, so that the caller can get
        // proper namespace binding.
        schemaDoc.restoreNSSupport();

        return retObj;
    }

    public String schemaDocument2SystemId(XSDocumentInfo schemaDoc) {
        return (String)fDoc2SystemId.get(schemaDoc.fSchemaElement);
    }
    
    // This method determines whether there is a group
    // (attributeGroup) which the given one has redefined by
    // restriction.  If so, it returns it; else it returns null.
    // @param type:  whether what's been redefined is an
    // attributeGroup or a group;
    // @param name:  the QName of the component doing the redefining.
    // @param currSchema:  schema doc in which the redefining component lives.
    // @return:  Object representing decl redefined if present, null
    // otherwise.
    Object getGrpOrAttrGrpRedefinedByRestriction(int type, QName name, XSDocumentInfo currSchema, Element elmNode) {
        String realName = name.uri != null?name.uri+","+name.localpart:
            ","+name.localpart;
        String nameToFind = null;
        switch (type) {
        case ATTRIBUTEGROUP_TYPE:
            nameToFind = (String)fRedefinedRestrictedAttributeGroupRegistry.get(realName);
            break;
        case GROUP_TYPE:
            nameToFind = (String)fRedefinedRestrictedGroupRegistry.get(realName);
            break;
        default:
            return null;
        }
        if (nameToFind == null) return null;
        int commaPos = nameToFind.indexOf(",");
        QName qNameToFind = new QName(XMLSymbols.EMPTY_STRING, nameToFind.substring(commaPos+1),
                nameToFind.substring(commaPos), (commaPos == 0)? null : nameToFind.substring(0, commaPos));
        Object retObj = getGlobalDecl(currSchema, type, qNameToFind, elmNode);
        if(retObj == null) {
            switch (type) {
            case ATTRIBUTEGROUP_TYPE:
                reportSchemaError("src-redefine.7.2.1", new Object []{name.localpart}, elmNode);
                break;
            case GROUP_TYPE:
                reportSchemaError("src-redefine.6.2.1", new Object []{name.localpart}, elmNode);
                break;
            }
            return null;
        }
        return retObj;
    } // getGrpOrAttrGrpRedefinedByRestriction(int, QName, XSDocumentInfo):  Object
    
    // Since ID constraints can occur in local elements, unless we
    // wish to completely traverse all our DOM trees looking for ID
    // constraints while we're building our global name registries,
    // which seems terribly inefficient, we need to resolve keyrefs
    // after all parsing is complete.  This we can simply do by running through
    // fIdentityConstraintRegistry and calling traverseKeyRef on all
    // of the KeyRef nodes.  This unfortunately removes this knowledge
    // from the elementTraverser class (which must ignore keyrefs),
    // but there seems to be no efficient way around this...
    protected void resolveKeyRefs() {
        for (int i=0; i<fKeyrefStackPos; i++) {
            XSDocumentInfo keyrefSchemaDoc = fKeyrefsMapXSDocumentInfo[i];
            keyrefSchemaDoc.fNamespaceSupport.makeGlobal();
            keyrefSchemaDoc.fNamespaceSupport.setEffectiveContext( fKeyrefNamespaceContext[i] );
            SchemaGrammar keyrefGrammar = fGrammarBucket.getGrammar(keyrefSchemaDoc.fTargetNamespace);
            // need to set <keyref> to hidden before traversing it,
            // because it has global scope
           	DOMUtil.setHidden(fKeyrefs[i], fHiddenNodes);
            fKeyrefTraverser.traverse(fKeyrefs[i], fKeyrefElems[i], keyrefSchemaDoc, keyrefGrammar);
        }
    } // end resolveKeyRefs
    
    // an accessor method.  Just makes sure callers
    // who want the Identity constraint registry vaguely know what they're about.
    protected Hashtable getIDRegistry() {
        return fUnparsedIdentityConstraintRegistry;
    }
    // an accessor method.  
    protected Hashtable getIDRegistry_sub() {
        return fUnparsedIdentityConstraintRegistrySub;
    }
    
   
    
    // This method squirrels away <keyref> declarations--along with the element
    // decls and namespace bindings they might find handy.
    protected void storeKeyRef (Element keyrefToStore, XSDocumentInfo schemaDoc,
            XSElementDecl currElemDecl) {
        String keyrefName = DOMUtil.getAttrValue(keyrefToStore, SchemaSymbols.ATT_NAME);
        if (keyrefName.length() != 0) {
            String keyrefQName = schemaDoc.fTargetNamespace == null?
                    "," + keyrefName: schemaDoc.fTargetNamespace+","+keyrefName;
            checkForDuplicateNames(keyrefQName, IDENTITYCONSTRAINT_TYPE, fUnparsedIdentityConstraintRegistry, fUnparsedIdentityConstraintRegistrySub, keyrefToStore, schemaDoc);
        }
        // now set up all the registries we'll need...
        
        // check array sizes
        if (fKeyrefStackPos == fKeyrefs.length) {
            Element [] elemArray = new Element [fKeyrefStackPos + INC_KEYREF_STACK_AMOUNT];
            System.arraycopy(fKeyrefs, 0, elemArray, 0, fKeyrefStackPos);
            fKeyrefs = elemArray;
            XSElementDecl [] declArray = new XSElementDecl [fKeyrefStackPos + INC_KEYREF_STACK_AMOUNT];
            System.arraycopy(fKeyrefElems, 0, declArray, 0, fKeyrefStackPos);
            fKeyrefElems = declArray;
            String[][] stringArray = new String [fKeyrefStackPos + INC_KEYREF_STACK_AMOUNT][];
            System.arraycopy(fKeyrefNamespaceContext, 0, stringArray, 0, fKeyrefStackPos);
            fKeyrefNamespaceContext = stringArray;
            
            XSDocumentInfo [] xsDocumentInfo = new XSDocumentInfo [fKeyrefStackPos + INC_KEYREF_STACK_AMOUNT];
            System.arraycopy(fKeyrefsMapXSDocumentInfo, 0, xsDocumentInfo, 0, fKeyrefStackPos);
            fKeyrefsMapXSDocumentInfo = xsDocumentInfo;
            
        }
        fKeyrefs[fKeyrefStackPos] = keyrefToStore;
        fKeyrefElems[fKeyrefStackPos] = currElemDecl;
        fKeyrefNamespaceContext[fKeyrefStackPos] = schemaDoc.fNamespaceSupport.getEffectiveLocalContext();
        
        fKeyrefsMapXSDocumentInfo[fKeyrefStackPos++] = schemaDoc; 
    } // storeKeyref (Element, XSDocumentInfo, XSElementDecl): void
    
    
    
resolveSchema method is responsible for resolving location of the schema (using XMLEntityResolver),
and if it was succefully resolved getting the schema Document.
Params:
desc – 
mustResolve – 
referElement – 
Returns:
A schema Element or null./**
     * resolveSchema method is responsible for resolving location of the schema (using XMLEntityResolver),
     * and if it was succefully resolved getting the schema Document.
     * @param desc
     * @param mustResolve
     * @param referElement
     * @return A schema Element or null.
     */
    private Element resolveSchema(XSDDescription desc, boolean mustResolve,
                                  Element referElement, boolean usePairs) {
        XMLInputSource schemaSource = null;
        try {
            Hashtable pairs = usePairs ? fLocationPairs : EMPTY_TABLE;
            schemaSource = XMLSchemaLoader.resolveDocument(desc, pairs, fEntityResolver);
        }
        catch (IOException ex) {
            if (mustResolve) {
                reportSchemaError("schema_reference.4",
                        new Object[]{desc.getLocationHints()[0]},
                        referElement);
            }
            else {
                reportSchemaWarning("schema_reference.4",
                        new Object[]{desc.getLocationHints()[0]},
                        referElement);
            }
        }
        if (schemaSource instanceof DOMInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (DOMInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);    
        } // DOMInputSource
        else if (schemaSource instanceof SAXInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (SAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);         
        } // SAXInputSource
        else if (schemaSource instanceof StAXInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (StAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement); 
        } // StAXInputSource
        else if (schemaSource instanceof XSInputSource) {
            return getSchemaDocument((XSInputSource) schemaSource, desc);
        } // XSInputSource
        return getSchemaDocument(desc.getTargetNamespace(), schemaSource, mustResolve, desc.getContextType(), referElement);
    } // getSchema(String, String, String, boolean, short):  Document

    private Element resolveSchema(XMLInputSource schemaSource, XSDDescription desc,
            boolean mustResolve, Element referElement) {

        if (schemaSource instanceof DOMInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (DOMInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);    
        } // DOMInputSource
        else if (schemaSource instanceof SAXInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (SAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement);         
        } // SAXInputSource
        else if (schemaSource instanceof StAXInputSource) {
            return getSchemaDocument(desc.getTargetNamespace(), (StAXInputSource) schemaSource, mustResolve, desc.getContextType(), referElement); 
        } // StAXInputSource
        else if (schemaSource instanceof XSInputSource) {
            return getSchemaDocument((XSInputSource) schemaSource, desc);
        } // XSInputSource
        return getSchemaDocument(desc.getTargetNamespace(), schemaSource, mustResolve, desc.getContextType(), referElement);
    }

    private XMLInputSource resolveSchemaSource(XSDDescription desc, boolean mustResolve,
            Element referElement, boolean usePairs) {

        XMLInputSource schemaSource = null;
        try {
            Hashtable pairs = usePairs ? fLocationPairs : EMPTY_TABLE;
            schemaSource = XMLSchemaLoader.resolveDocument(desc, pairs, fEntityResolver);
        }
        catch (IOException ex) {
            if (mustResolve) {
                reportSchemaError("schema_reference.4",
                        new Object[]{desc.getLocationHints()[0]},
                        referElement);
            }
            else {
                reportSchemaWarning("schema_reference.4",
                        new Object[]{desc.getLocationHints()[0]},
                        referElement);
            }
        }
        
        return schemaSource;
    }
    
    
getSchemaDocument method uses XMLInputSource to parse a schema document.
Params:
schemaNamespace – 
schemaSource – 
mustResolve – 
referType – 
referElement – 
Returns:
A schema Element./**
     * getSchemaDocument method uses XMLInputSource to parse a schema document.
     * @param schemaNamespace
     * @param schemaSource
     * @param mustResolve
     * @param referType
     * @param referElement
     * @return A schema Element.
     */
    private Element getSchemaDocument(String schemaNamespace, XMLInputSource schemaSource,
            boolean mustResolve, short referType, Element referElement) {
        
        boolean hasInput = true;
        IOException exception = null;
        // contents of this method will depend on the system we adopt for entity resolution--i.e., XMLEntityHandler, EntityHandler, etc.
        Element schemaElement = null;
        try {
            // when the system id and byte stream and character stream
            // of the input source are all null, it's
            // impossible to find the schema document. so we skip in
            // this case. otherwise we'll receive some NPE or
            // file not found errors. but schemaHint=="" is perfectly
            // legal for import.
            if (schemaSource != null &&
                    (schemaSource.getSystemId() != null ||
                            schemaSource.getByteStream() != null ||
                            schemaSource.getCharacterStream() != null)) {
                
                // When the system id of the input source is used, first try to
                // expand it, and check whether the same document has been
                // parsed before. If so, return the document corresponding to
                // that system id.
                XSDKey key = null;
                String schemaId = null;
                if (referType != XSDDescription.CONTEXT_PREPARSE){
                    schemaId = XMLEntityManager.expandSystemId(schemaSource.getSystemId(), schemaSource.getBaseSystemId(), false);
                    key = new XSDKey(schemaId, referType, schemaNamespace);
                    if((schemaElement = (Element)fTraversed.get(key)) != null) {
                        fLastSchemaWasDuplicate = true;
                        return schemaElement;
                    }
                }
                
                fSchemaParser.parse(schemaSource);
                Document schemaDocument = fSchemaParser.getDocument();
                schemaElement = schemaDocument != null ? DOMUtil.getRoot(schemaDocument) : null;
                return getSchemaDocument0(key, schemaId, schemaElement);
            }
            else {
                hasInput = false;
            }
        }
        catch (IOException ex) {
            exception = ex;
        }
        return getSchemaDocument1(mustResolve, hasInput, schemaSource, referElement, exception);
    } // getSchemaDocument(String, XMLInputSource, boolean, short, Element): Element
    
    
getSchemaDocument method uses SAXInputSource to parse a schema document.
Params:
schemaNamespace – 
schemaSource – 
mustResolve – 
referType – 
referElement – 
Returns:
A schema Element./**
     * getSchemaDocument method uses SAXInputSource to parse a schema document.
     * @param schemaNamespace
     * @param schemaSource
     * @param mustResolve
     * @param referType
     * @param referElement
     * @return A schema Element.
     */
    private Element getSchemaDocument(String schemaNamespace, SAXInputSource schemaSource,
            boolean mustResolve, short referType, Element referElement) {
        XMLReader parser = schemaSource.getXMLReader();
        InputSource inputSource = schemaSource.getInputSource();
        boolean hasInput = true;
        IOException exception = null;
        Element schemaElement = null;
        try {
            if (inputSource != null &&
                    (inputSource.getSystemId() != null ||
                     inputSource.getByteStream() != null ||
                     inputSource.getCharacterStream() != null)) {
                
                // check whether the same document has been parsed before. 
                // If so, return the document corresponding to that system id.
                XSDKey key = null;
                String schemaId = null;
                if (referType != XSDDescription.CONTEXT_PREPARSE) {
                    schemaId = XMLEntityManager.expandSystemId(inputSource.getSystemId(), schemaSource.getBaseSystemId(), false);
                    key = new XSDKey(schemaId, referType, schemaNamespace);
                    if ((schemaElement = (Element) fTraversed.get(key)) != null) {
                        fLastSchemaWasDuplicate = true;
                        return schemaElement;
                    }
                }
                
                boolean namespacePrefixes = false;
                if (parser != null) {
                    try {
                        namespacePrefixes = parser.getFeature(NAMESPACE_PREFIXES);
                    }
                    catch (SAXException se) {}
                }
                else {
                    try {
                        parser = XMLReaderFactory.createXMLReader();
                    }
                    // If something went wrong with the factory
                    // just use our own SAX parser.
                    catch (SAXException se) {
                        parser = new SAXParser();
                    }
                    try {
                        parser.setFeature(NAMESPACE_PREFIXES, true);
                        namespacePrefixes = true;
                        // If this is a Xerces SAX parser set the security manager if there is one
                        if (parser instanceof SAXParser) {
                            Object securityManager = fSchemaParser.getProperty(SECURITY_MANAGER);
                            if (securityManager != null) {
                                parser.setProperty(SECURITY_MANAGER, securityManager);
                            }
                        }
                    }
                    catch (SAXException se) {}
                }
                // If XML names and Namespace URIs are already internalized we
                // can avoid running them through the SymbolTable.
                boolean stringsInternalized = false;
                try {
                    stringsInternalized = parser.getFeature(STRING_INTERNING);
                }
                catch (SAXException exc) {
                    // The feature isn't recognized or getting it is not supported.
                    // In either case, assume that strings are not internalized.
                }
                if (fXSContentHandler == null) {
                    fXSContentHandler = new SchemaContentHandler();
                }
                fXSContentHandler.reset(fSchemaParser, fSymbolTable, 
                        namespacePrefixes, stringsInternalized);
                parser.setContentHandler(fXSContentHandler);
                parser.setErrorHandler(fErrorReporter.getSAXErrorHandler());
                
                parser.parse(inputSource);
                // Disconnect the schema loader and other objects from the XMLReader
                try {
                    parser.setContentHandler(null);
                    parser.setErrorHandler(null);
                }
                // Ignore any exceptions thrown by the XMLReader. Old versions of SAX
                // required an XMLReader to throw a NullPointerException if an attempt
                // to set a handler to null was made.
                catch (Exception e) {}
                
                Document schemaDocument = fXSContentHandler.getDocument();
                schemaElement = schemaDocument != null ? DOMUtil.getRoot(schemaDocument) : null;
                return getSchemaDocument0(key, schemaId, schemaElement);
            }
            else {
                hasInput = false;
            }
        }
        catch (SAXParseException spe) {
            throw SAX2XNIUtil.createXMLParseException0(spe);
        }
        catch (SAXException se) {
            throw SAX2XNIUtil.createXNIException0(se);
        }
        catch (IOException ioe) {
            exception = ioe;
        }
        return getSchemaDocument1(mustResolve, hasInput, schemaSource, referElement, exception);
    } // getSchemaDocument(String, SAXInputSource, boolean, short, Element): Element
    
    
getSchemaDocument method uses DOMInputSource to parse a schema document.
Params:
schemaNamespace – 
schemaSource – 
mustResolve – 
referType – 
referElement – 
Returns:
A schema Element./**
     * getSchemaDocument method uses DOMInputSource to parse a schema document.
     * @param schemaNamespace
     * @param schemaSource
     * @param mustResolve
     * @param referType
     * @param referElement
     * @return A schema Element.
     */
    private Element getSchemaDocument(String schemaNamespace, DOMInputSource schemaSource,
            boolean mustResolve, short referType, Element referElement) {
        boolean hasInput = true;
        IOException exception = null;
        Element schemaElement = null;
        Element schemaRootElement = null;
        
        final Node node = schemaSource.getNode();
        short nodeType = -1;
        if (node != null) {
            nodeType = node.getNodeType();
            if (nodeType == Node.DOCUMENT_NODE) {
                schemaRootElement = DOMUtil.getRoot((Document) node);
            }
            else if (nodeType == Node.ELEMENT_NODE) {
                schemaRootElement = (Element) node;
            }
        }
        
        try {
            if (schemaRootElement != null) {
                // check whether the same document has been parsed before. 
                // If so, return the document corresponding to that system id.
                XSDKey key = null;
                String schemaId = null;
                if (referType != XSDDescription.CONTEXT_PREPARSE) {
                    schemaId = XMLEntityManager.expandSystemId(schemaSource.getSystemId(), schemaSource.getBaseSystemId(), false);
                    boolean isDocument = (nodeType == Node.DOCUMENT_NODE);
                    if (!isDocument) {
                        Node parent = schemaRootElement.getParentNode();
                        if (parent != null) {
                            isDocument = (parent.getNodeType() == Node.DOCUMENT_NODE);
                        }
                    }
                    if (isDocument) {
                        key = new XSDKey(schemaId, referType, schemaNamespace);
                        if ((schemaElement = (Element) fTraversed.get(key)) != null) {
                            fLastSchemaWasDuplicate = true;
                            return schemaElement;
                        }
                    }
                }

                schemaElement = schemaRootElement;
                return getSchemaDocument0(key, schemaId, schemaElement);
            }
            else {
                hasInput = false;
            }
        }
        catch (IOException ioe) {
            exception = ioe;
        }
        return getSchemaDocument1(mustResolve, hasInput, schemaSource, referElement, exception);
    } // getSchemaDocument(String, DOMInputSource, boolean, short, Element): Element
    
    
getSchemaDocument method uses StAXInputSource to parse a schema document.
Params:
schemaNamespace – 
schemaSource – 
mustResolve – 
referType – 
referElement – 
Returns:
A schema Element./**
     * getSchemaDocument method uses StAXInputSource to parse a schema document.
     * @param schemaNamespace
     * @param schemaSource
     * @param mustResolve
     * @param referType
     * @param referElement
     * @return A schema Element.
     */
    private Element getSchemaDocument(String schemaNamespace, StAXInputSource schemaSource,
            boolean mustResolve, short referType, Element referElement) {
        IOException exception = null;
        Element schemaElement = null;
        try {
            final boolean consumeRemainingContent = schemaSource.shouldConsumeRemainingContent();
            final XMLStreamReader streamReader = schemaSource.getXMLStreamReader();
            final XMLEventReader eventReader = schemaSource.getXMLEventReader();
            
            // check whether the same document has been parsed before. 
            // If so, return the document corresponding to that system id.
            XSDKey key = null;
            String schemaId = null;
            if (referType != XSDDescription.CONTEXT_PREPARSE) {
                schemaId = XMLEntityManager.expandSystemId(schemaSource.getSystemId(), schemaSource.getBaseSystemId(), false);
                boolean isDocument = consumeRemainingContent;
                if (!isDocument) {
                    if (streamReader != null) {
                        isDocument = (streamReader.getEventType() == XMLStreamReader.START_DOCUMENT);
                    }
                    else {
                        isDocument = eventReader.peek().isStartDocument();
                    }
                }
                if (isDocument) {
                    key = new XSDKey(schemaId, referType, schemaNamespace);
                    if ((schemaElement = (Element) fTraversed.get(key)) != null) {
                        fLastSchemaWasDuplicate = true;
                        return schemaElement;
                    }
                }
            }
            
            if (fStAXSchemaParser == null) {
                fStAXSchemaParser = new StAXSchemaParser();
            }
            fStAXSchemaParser.reset(fSchemaParser, fSymbolTable);
            
            if (streamReader != null) {
                fStAXSchemaParser.parse(streamReader);
                if (consumeRemainingContent) {
                    while (streamReader.hasNext()) {
                        streamReader.next();
                    }
                }
            }
            else {
                fStAXSchemaParser.parse(eventReader);
                if (consumeRemainingContent) {
                    while (eventReader.hasNext()) {
                        eventReader.nextEvent();
                    }
                }
            }
            Document schemaDocument = fStAXSchemaParser.getDocument();
            schemaElement = schemaDocument != null ? DOMUtil.getRoot(schemaDocument) : null;
            return getSchemaDocument0(key, schemaId, schemaElement);
        }
        catch (XMLStreamException e) {
            Throwable t = e.getNestedException();
            if (t instanceof IOException) {
                exception = (IOException) t;
            }
            else {
                StAXLocationWrapper slw = new StAXLocationWrapper();
                slw.setLocation(e.getLocation());
                throw new XMLParseException(slw, e.getMessage(), e);
            }
        }
        catch (IOException e) {
            exception = e;
        }
        return getSchemaDocument1(mustResolve, true, schemaSource, referElement, exception);
    } // getSchemaDocument(String, StAXInputSource, boolean, short, Element): Element
    
    
Code shared between the various getSchemaDocument() methods which
stores mapping information for the document.
/**
     * Code shared between the various getSchemaDocument() methods which
     * stores mapping information for the document.
     */
    private Element getSchemaDocument0(XSDKey key, String schemaId, Element schemaElement) {
        // now we need to store the mapping information from system id
        // to the document. also from the document to the system id.
        if (key != null) {
            fTraversed.put(key, schemaElement);
        }
        if (schemaId != null) {
            fDoc2SystemId.put(schemaElement, schemaId);
        }
        fLastSchemaWasDuplicate = false;
        return schemaElement;
    } // getSchemaDocument0(XSDKey, String, Element): Element
    
    
Error handling code shared between the various getSchemaDocument() methods.
/**
     * Error handling code shared between the various getSchemaDocument() methods.
     */
    private Element getSchemaDocument1(boolean mustResolve, boolean hasInput, 
            XMLInputSource schemaSource, Element referElement, IOException ioe) {
        // either an error occured (exception), or empty input source was
        // returned, we need to report an error or a warning
        if (mustResolve) {
            if (hasInput) {
                reportSchemaError("schema_reference.4",
                        new Object[]{schemaSource.getSystemId()},
                        referElement, ioe);
            }
            else {
                reportSchemaError("schema_reference.4",
                        new Object[]{schemaSource == null ? "" : schemaSource.getSystemId()},
                        referElement, ioe);
            }
        }
        else if (hasInput) {
            reportSchemaWarning("schema_reference.4",
                    new Object[]{schemaSource.getSystemId()},
                    referElement, ioe);
        }
        
        fLastSchemaWasDuplicate = false;
        return null;
    } // getSchemaDocument1(boolean, boolean, XMLInputSource, Element): Element
    
    
getSchemaDocument method uses XMLInputSource to parse a schema document.
Params:
schemaNamespace – 
schemaSource – 
mustResolve – 
referType – 
referElement – 
Returns:
A schema Element./**
     * getSchemaDocument method uses XMLInputSource to parse a schema document.
     * @param schemaNamespace
     * @param schemaSource
     * @param mustResolve
     * @param referType
     * @param referElement
     * @return A schema Element.
     */
    private Element getSchemaDocument(XSInputSource schemaSource, XSDDescription desc) {

        SchemaGrammar[] grammars = schemaSource.getGrammars();
        short referType = desc.getContextType();
        
        if (grammars != null && grammars.length > 0) {
            Vector expandedGrammars = expandGrammars(grammars);
            // check for existing grammars in our bucket
            // and if there exist any, and namespace growth is
            // not enabled - we do nothing
            if (fNamespaceGrowth || !existingGrammars(expandedGrammars)) {
                addGrammars(expandedGrammars);
                if (referType == XSDDescription.CONTEXT_PREPARSE) {
                    desc.setTargetNamespace(grammars[0].getTargetNamespace());
                }
            }
        }
        else {
            XSObject[] components = schemaSource.getComponents();
            if (components != null && components.length > 0) {
                Hashtable importDependencies = new Hashtable();
                Vector expandedComponents = expandComponents(components, importDependencies);
                if (fNamespaceGrowth || canAddComponents(expandedComponents)) {
                    addGlobalComponents(expandedComponents, importDependencies);
                    if (referType == XSDDescription.CONTEXT_PREPARSE) {
                        desc.setTargetNamespace(components[0].getNamespace());
                    }
                }
            }
        }
        return null;
    } // getSchemaDocument(String, XSInputSource, boolean, short, Element): Element

    private Vector expandGrammars(SchemaGrammar[] grammars) {
        Vector currGrammars = new Vector();

        for (int i=0; i<grammars.length; i++) {
            if (!currGrammars.contains(grammars[i])) {
                currGrammars.add(grammars[i]);
            }
        }

        // for all (recursively) imported grammars
        SchemaGrammar sg1, sg2;
        Vector gs;
        for (int i = 0; i < currGrammars.size(); i++) {
            // get the grammar
            sg1 = (SchemaGrammar)currGrammars.elementAt(i);
            // we need to add grammars imported by sg1 too
            gs = sg1.getImportedGrammars();
            // for all grammars imported by sg2, but not in the vector
            // we add them to the vector
            if (gs == null) {
                continue;
            }

            for (int j = gs.size() - 1; j >= 0; j--) {
                sg2 = (SchemaGrammar)gs.elementAt(j);
                if (!currGrammars.contains(sg2)) {
                    currGrammars.addElement(sg2);
                }
            }
        }

        return currGrammars;
    }

    private boolean existingGrammars(Vector grammars) {
        int length = grammars.size();
        final XSDDescription desc = new XSDDescription();
        
        for (int i=0; i < length; i++) {
            final SchemaGrammar sg1 = (SchemaGrammar)grammars.elementAt(i);
            desc.setNamespace(sg1.getTargetNamespace());
            
            final SchemaGrammar sg2 = findGrammar(desc, false);
            if (sg2 != null) {
                return true;
            }
        }

        return false;
    }

    private boolean canAddComponents(Vector components) {
        final int size = components.size();
        final XSDDescription desc = new XSDDescription(); 
        for (int i=0; i<size; i++) {
            XSObject component = (XSObject) components.elementAt(i);
            if (!canAddComponent(component, desc)) {
                return false;
            }
        }
        return true;
    }

    private boolean canAddComponent(XSObject component, XSDDescription desc) {
        desc.setNamespace(component.getNamespace());

        final SchemaGrammar sg = findGrammar(desc, false);
        if (sg == null) {
            return true;
        }
        else if (sg.isImmutable()) {
            return false;
        }

        short componentType = component.getType();
        final String name = component.getName();

        switch (componentType) {
        case XSConstants.TYPE_DEFINITION :
            if (sg.getGlobalTypeDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.ATTRIBUTE_DECLARATION :
            if (sg.getGlobalAttributeDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.ATTRIBUTE_GROUP :
            if (sg.getGlobalAttributeDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.ELEMENT_DECLARATION :
            if (sg.getGlobalElementDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.MODEL_GROUP_DEFINITION :
            if (sg.getGlobalGroupDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.NOTATION_DECLARATION :
            if (sg.getGlobalNotationDecl(name) == component) {
                return true;
            }
            break;
        case XSConstants.IDENTITY_CONSTRAINT :
        case XSConstants.ATTRIBUTE_USE :
        default :
            return true;
        }
        return false;
    }

    private void addGrammars(Vector grammars) {
        int length = grammars.size();
        XSDDescription desc = new XSDDescription();
        
        for (int i=0; i < length; i++) {
            final SchemaGrammar sg1 = (SchemaGrammar)grammars.elementAt(i);
            desc.setNamespace(sg1.getTargetNamespace());

            final SchemaGrammar sg2 = findGrammar(desc, fNamespaceGrowth);
            if (sg1 != sg2) {
                addGrammarComponents(sg1, sg2);
            }
        }
    }

    private void addGrammarComponents(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        if (dstGrammar == null) {
            createGrammarFrom(srcGrammar);
            return;
        }

        SchemaGrammar tmpGrammar = dstGrammar;
        if (tmpGrammar.isImmutable()) {
            tmpGrammar = createGrammarFrom(dstGrammar);
        }

        // add any new locations
        addNewGrammarLocations(srcGrammar, tmpGrammar);
        
        // add any new imported grammars
        addNewImportedGrammars(srcGrammar, tmpGrammar);

        // add any new global components
        addNewGrammarComponents(srcGrammar, tmpGrammar);
    }

    private SchemaGrammar createGrammarFrom(SchemaGrammar grammar) {
        SchemaGrammar newGrammar = new SchemaGrammar(grammar);
        fGrammarBucket.putGrammar(newGrammar);
        // update all the grammars in the bucket to point to the new grammar.
        updateImportListWith(newGrammar);
        // update import list of the new grammar
        updateImportListFor(newGrammar);
        return newGrammar;
    }

    private void addNewGrammarLocations(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        final StringList locations = srcGrammar.getDocumentLocations();
        final int locSize = locations.size();
        final StringList locations2 = dstGrammar.getDocumentLocations();
        
        for (int i=0; i<locSize; i++) {
            String loc = locations.item(i);
            if (!locations2.contains(loc)) {
                dstGrammar.addDocument(null, loc);
            }
        }
    }

    private void addNewImportedGrammars(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        final Vector src = srcGrammar.getImportedGrammars();
        if (src != null) {
            Vector dst = dstGrammar.getImportedGrammars();
            if (dst == null) {
                dst = new Vector();
                dstGrammar.setImportedGrammars(dst);
            }
            final int size = src.size();
            for (int i=0; i<size; i++) {
                SchemaGrammar sg = (SchemaGrammar) src.elementAt(i);
                // Can't use the object from the source import list directly.
                // It's possible there is already a grammar with the same
                // namespace in the bucket but a different object.
                // This can happen if the bucket has grammar A1, and we try
                // to add B and A2, where A2 imports B. When B is added, we
                // create a new object B' and store it in the bucket. Then we
                // try to merge A2 and A1. We can't use B. Need to get B' from
                // the bucket and store it in A's import list.
                SchemaGrammar sg1 = fGrammarBucket.getGrammar(sg.getTargetNamespace());
                if (sg1 != null) {
                    sg = sg1;
                }
                if (!containedImportedGrammar(dst, sg)) {
                    dst.add(sg);
                }
            }
        }
    }

    private void updateImportList(Vector importedSrc, Vector importedDst)
    {
        final int size = importedSrc.size();

        for (int i=0; i<size; i++) {
            final SchemaGrammar sg = (SchemaGrammar) importedSrc.elementAt(i);
            if (!containedImportedGrammar(importedDst, sg)) {
                importedDst.add(sg);
            }
        }
    }

    private void addNewGrammarComponents(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        dstGrammar.resetComponents();
        addGlobalElementDecls(srcGrammar, dstGrammar);
        addGlobalAttributeDecls(srcGrammar, dstGrammar);
        addGlobalAttributeGroupDecls(srcGrammar, dstGrammar);
        addGlobalGroupDecls(srcGrammar, dstGrammar);
        addGlobalTypeDecls(srcGrammar, dstGrammar);
        addGlobalNotationDecls(srcGrammar, dstGrammar);
    }

    private void addGlobalElementDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.ELEMENT_DECLARATION);
        int len = components.getLength();
        XSElementDecl srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSElementDecl) components.item(i);
            dstDecl = dstGrammar.getGlobalElementDecl(srcDecl.getName()); 
            if (dstDecl == null) {
                dstGrammar.addGlobalElementDecl(srcDecl);
            }
            else if (dstDecl != srcDecl){
                // TODO: if not tolerating duplicate, generate an error message
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.ELEMENT_DECLARATION);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());

            srcDecl = (XSElementDecl)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalElementDecl(name, location); 
            if ( dstDecl == null) {
                dstGrammar.addGlobalElementDecl(srcDecl, location);
            }
            else if (dstDecl != srcDecl){
                // TODO: if not tolerating duplicate, generate an error message
            }
        }
    }
    
    private void addGlobalAttributeDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.ATTRIBUTE_DECLARATION);
        int len = components.getLength();
        XSAttributeDecl srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSAttributeDecl) components.item(i);
            dstDecl = dstGrammar.getGlobalAttributeDecl(srcDecl.getName()); 
            if (dstDecl == null) {
                dstGrammar.addGlobalAttributeDecl(srcDecl);
            }
            else if (dstDecl != srcDecl && !fTolerateDuplicates) {
                reportSharingError(srcDecl.getNamespace(), srcDecl.getName());
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.ATTRIBUTE_DECLARATION);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());
            
            srcDecl = (XSAttributeDecl)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalAttributeDecl(name, location); 
            if (dstDecl == null) {
                dstGrammar.addGlobalAttributeDecl(srcDecl, location);
            }
            // REVISIT - do we report an error?
            else if (dstDecl != srcDecl) {
            }
        }
    }

    private void addGlobalAttributeGroupDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.ATTRIBUTE_GROUP);
        int len = components.getLength();
        XSAttributeGroupDecl srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSAttributeGroupDecl) components.item(i);
            dstDecl = dstGrammar.getGlobalAttributeGroupDecl(srcDecl.getName());
            if (dstDecl == null) {
                dstGrammar.addGlobalAttributeGroupDecl(srcDecl);
            }
            else if (dstDecl != srcDecl && !fTolerateDuplicates) {
                reportSharingError(srcDecl.getNamespace(), srcDecl.getName());
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.ATTRIBUTE_GROUP);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());
            
            srcDecl = (XSAttributeGroupDecl)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalAttributeGroupDecl(name, location);
            if (dstDecl == null) {
                dstGrammar.addGlobalAttributeGroupDecl(srcDecl, location);
            }
            // REVISIT - do we report an error?
            else if (dstDecl != srcDecl) {
            }
        }
    }
    
    private void addGlobalNotationDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.NOTATION_DECLARATION);
        int len = components.getLength();
        XSNotationDecl srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSNotationDecl) components.item(i);
            dstDecl = dstGrammar.getGlobalNotationDecl(srcDecl.getName());
            if (dstDecl == null) {
                dstGrammar.addGlobalNotationDecl(srcDecl);
            }
            else if (dstDecl != srcDecl && !fTolerateDuplicates) {
                reportSharingError(srcDecl.getNamespace(), srcDecl.getName());
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.NOTATION_DECLARATION);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());

            srcDecl = (XSNotationDecl)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalNotationDecl(name, location);
            if (dstDecl == null) {
                dstGrammar.addGlobalNotationDecl(srcDecl, location);
            }
            // REVISIT - do we report an error?
            else if (dstDecl != srcDecl) {
            }
        }
    }
    
    private void addGlobalGroupDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.MODEL_GROUP_DEFINITION);
        int len = components.getLength();
        XSGroupDecl srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSGroupDecl) components.item(i);
            dstDecl = dstGrammar.getGlobalGroupDecl(srcDecl.getName());
            if (dstDecl == null) {
                dstGrammar.addGlobalGroupDecl(srcDecl);
            }
            else if (srcDecl != dstDecl && !fTolerateDuplicates) {
                reportSharingError(srcDecl.getNamespace(), srcDecl.getName());
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.MODEL_GROUP_DEFINITION);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());

            srcDecl = (XSGroupDecl)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalGroupDecl(name, location);
            if (dstDecl == null) {
                dstGrammar.addGlobalGroupDecl(srcDecl, location);
            }
            // REVIST - do we report an error?
            else if (dstDecl != srcDecl) {
            }
        }
    }

    private void addGlobalTypeDecls(SchemaGrammar srcGrammar, SchemaGrammar dstGrammar) {
        XSNamedMap components = srcGrammar.getComponents(XSConstants.TYPE_DEFINITION);
        int len = components.getLength();
        XSTypeDefinition srcDecl, dstDecl;

        // add global components
        for (int i=0; i<len; i++) {
            srcDecl = (XSTypeDefinition) components.item(i);
            dstDecl = dstGrammar.getGlobalTypeDecl(srcDecl.getName());
            if (dstDecl == null) {
                dstGrammar.addGlobalTypeDecl(srcDecl);
            }
            else if (dstDecl != srcDecl && !fTolerateDuplicates) {
                reportSharingError(srcDecl.getNamespace(), srcDecl.getName());
            }
        }

        // add any extended (duplicate) global components
        ObjectList componentsExt = srcGrammar.getComponentsExt(XSConstants.TYPE_DEFINITION);
        len = componentsExt.getLength();

        for (int i=0; i<len; i+= 2) {
            final String key = (String) componentsExt.item(i);
            final int index = key.indexOf(',');
            final String location = key.substring(0, index);
            final String name = key.substring(index + 1, key.length());

            srcDecl = (XSTypeDefinition)componentsExt.item(i+1);
            dstDecl = dstGrammar.getGlobalTypeDecl(name, location);
            if (dstDecl == null) {
                dstGrammar.addGlobalTypeDecl(srcDecl, location);
            }
            // REVISIT - do we report an error?
            else if (dstDecl != srcDecl) {
            }
        }
    }

    private Vector expandComponents(XSObject[] components, Hashtable dependencies) {
        Vector newComponents = new Vector();
        
        for (int i=0; i<components.length; i++) {
            if (!newComponents.contains(components[i])) {
                newComponents.add(components[i]);
            }
        }
        
        for (int i=0; i<newComponents.size(); i++) {
            final XSObject component = (XSObject) newComponents.elementAt(i);
            expandRelatedComponents(component, newComponents, dependencies);
        }
        
        return newComponents;
    }
    
    private void expandRelatedComponents(XSObject component, Vector componentList, Hashtable dependencies) {
        short componentType = component.getType();
        switch (componentType) {
        case XSConstants.TYPE_DEFINITION :
            expandRelatedTypeComponents((XSTypeDefinition) component, componentList, component.getNamespace(), dependencies);
            break;
        case XSConstants.ATTRIBUTE_DECLARATION :
            expandRelatedAttributeComponents((XSAttributeDeclaration) component, componentList, component.getNamespace(), dependencies);
            break;
        case XSConstants.ATTRIBUTE_GROUP :
            expandRelatedAttributeGroupComponents((XSAttributeGroupDefinition) component, componentList, component.getNamespace(), dependencies);
        case XSConstants.ELEMENT_DECLARATION :
            expandRelatedElementComponents((XSElementDeclaration) component, componentList, component.getNamespace(), dependencies);
            break;
        case XSConstants.MODEL_GROUP_DEFINITION :
            expandRelatedModelGroupDefinitionComponents((XSModelGroupDefinition) component, componentList, component.getNamespace(), dependencies);
        case XSConstants.ATTRIBUTE_USE :
            //expandRelatedAttributeUseComponents((XSAttributeUse)component, componentList, dependencies);
        case XSConstants.NOTATION_DECLARATION :
        case XSConstants.IDENTITY_CONSTRAINT :
        default :
            break;
        }
    }

    private void expandRelatedAttributeComponents(XSAttributeDeclaration decl, Vector componentList, String namespace, Hashtable dependencies) {
        addRelatedType(decl.getTypeDefinition(), componentList, namespace, dependencies);

        /*final XSComplexTypeDefinition enclosingType = decl.getEnclosingCTDefinition();
        if (enclosingType != null) {
            addRelatedType(enclosingType, componentList, namespace, dependencies);
        }*/
    }

    private void expandRelatedElementComponents(XSElementDeclaration decl, Vector componentList, String namespace, Hashtable dependencies) {
        addRelatedType(decl.getTypeDefinition(), componentList, namespace, dependencies);
        
        /*final XSTypeDefinition enclosingType = decl.getEnclosingCTDefinition();
        if (enclosingType != null) {
            addRelatedType(enclosingType, componentList, namespace, dependencies);
        }*/

        final XSElementDeclaration subElemDecl = decl.getSubstitutionGroupAffiliation();
        if (subElemDecl != null) {
            addRelatedElement(subElemDecl, componentList, namespace, dependencies);
        }
    }
    
    private void expandRelatedTypeComponents(XSTypeDefinition type, Vector componentList, String namespace, Hashtable dependencies) {
        if (type instanceof XSComplexTypeDecl) {
            expandRelatedComplexTypeComponents((XSComplexTypeDecl) type, componentList, namespace, dependencies);
        }
        else if (type instanceof XSSimpleTypeDecl) {
            expandRelatedSimpleTypeComponents((XSSimpleTypeDefinition) type, componentList, namespace, dependencies);
        }
    }

    private void expandRelatedModelGroupDefinitionComponents(XSModelGroupDefinition modelGroupDef, Vector componentList,
            String namespace, Hashtable dependencies) {
        expandRelatedModelGroupComponents(modelGroupDef.getModelGroup(), componentList, namespace, dependencies);
    }

    private void expandRelatedAttributeGroupComponents(XSAttributeGroupDefinition attrGroup, Vector componentList
            , String namespace, Hashtable dependencies) {
        expandRelatedAttributeUsesComponents(attrGroup.getAttributeUses(), componentList, namespace, dependencies);
    }

    private void expandRelatedComplexTypeComponents(XSComplexTypeDecl type, Vector componentList, String namespace, Hashtable dependencies) {
        addRelatedType(type.getBaseType(), componentList, namespace, dependencies);
        expandRelatedAttributeUsesComponents(type.getAttributeUses(), componentList, namespace, dependencies);
        final XSParticle particle = type.getParticle();
        if (particle != null) {
            expandRelatedParticleComponents(particle, componentList, namespace, dependencies);
        }
    }

    private void expandRelatedSimpleTypeComponents(XSSimpleTypeDefinition type, Vector componentList, String namespace, Hashtable dependencies) {
        final XSTypeDefinition baseType = type.getBaseType();
        if (baseType != null) {
            addRelatedType(baseType, componentList, namespace, dependencies);
        }

        final XSTypeDefinition itemType = type.getItemType();
        if (itemType != null) {
            addRelatedType(itemType, componentList, namespace, dependencies);
        }
        
        final XSTypeDefinition primitiveType = type.getPrimitiveType();
        if (primitiveType != null) {
            addRelatedType(primitiveType, componentList, namespace, dependencies);
        }

        final XSObjectList memberTypes = type.getMemberTypes();
        if (memberTypes.size() > 0) {
            for (int i=0; i<memberTypes.size(); i++) {
                addRelatedType((XSTypeDefinition)memberTypes.item(i), componentList, namespace, dependencies);
            }
        }
    }
    
    private void expandRelatedAttributeUsesComponents(XSObjectList attrUses, Vector componentList,
            String namespace, Hashtable dependencies) {
        final int attrUseSize = (attrUses == null) ? 0 : attrUses.size();
        for (int i=0; i<attrUseSize; i++) {
            expandRelatedAttributeUseComponents((XSAttributeUse)attrUses.item(i), componentList, namespace, dependencies);
        }
    }

    private void expandRelatedAttributeUseComponents(XSAttributeUse component, Vector componentList,
            String namespace, Hashtable dependencies) {
        addRelatedAttribute(component.getAttrDeclaration(), componentList, namespace, dependencies);
    }

    private void expandRelatedParticleComponents(XSParticle component, Vector componentList,
            String namespace, Hashtable dependencies) {
        XSTerm term = component.getTerm();
        switch (term.getType()) {
        case XSConstants.ELEMENT_DECLARATION :
            addRelatedElement((XSElementDeclaration) term, componentList, namespace, dependencies);
            break;
        case XSConstants.MODEL_GROUP :
            expandRelatedModelGroupComponents((XSModelGroup) term, componentList, namespace, dependencies);
            break;
        default:
            break;
        }
    }

    private void expandRelatedModelGroupComponents(XSModelGroup modelGroup, Vector componentList,
            String namespace, Hashtable dependencies) {
        XSObjectList particles = modelGroup.getParticles();
        final int length = (particles == null) ? 0 : particles.getLength();
        for (int i=0; i<length; i++) {
            expandRelatedParticleComponents((XSParticle)particles.item(i), componentList, namespace, dependencies);
        }
    }
    
    private void addRelatedType(XSTypeDefinition type, Vector componentList, String namespace, Hashtable dependencies) {
        if (!type.getAnonymous()) {
            if (!SchemaSymbols.URI_SCHEMAFORSCHEMA.equals(type.getNamespace())) { //REVISIT - do we use == instead
                if (!componentList.contains(type)) {
                    final Vector importedNamespaces = findDependentNamespaces(namespace, dependencies);
                    addNamespaceDependency(namespace, type.getNamespace(), importedNamespaces);
                    componentList.add(type);
                }
            }
        }
        else {
            expandRelatedTypeComponents(type, componentList, namespace, dependencies);
        }
    }
    
    private void addRelatedElement(XSElementDeclaration decl, Vector componentList, String namespace, Hashtable dependencies) {
        if (decl.getScope() == XSConstants.SCOPE_GLOBAL) {
            if (!componentList.contains(decl)) {
                Vector importedNamespaces = findDependentNamespaces(namespace, dependencies);
                addNamespaceDependency(namespace, decl.getNamespace(), importedNamespaces);
                componentList.add(decl);
            }
        }
        else {
            expandRelatedElementComponents(decl, componentList, namespace, dependencies);
        }
    }

    private void addRelatedAttribute(XSAttributeDeclaration decl, Vector componentList, String namespace, Hashtable dependencies) {
        if (decl.getScope() == XSConstants.SCOPE_GLOBAL) {
            if (!componentList.contains(decl)) {
                Vector importedNamespaces = findDependentNamespaces(namespace, dependencies);
                addNamespaceDependency(namespace, decl.getNamespace(), importedNamespaces);
                componentList.add(decl);
            }
        }
        else {
            expandRelatedAttributeComponents(decl, componentList, namespace, dependencies);
        }
    }

    private void addGlobalComponents(Vector components, Hashtable importDependencies) {
        final XSDDescription desc = new XSDDescription();
        final int size = components.size();
        
        for (int i=0; i<size; i++) {
            addGlobalComponent((XSObject) components.elementAt(i), desc);
        }
        updateImportDependencies(importDependencies);
    }

    private void addGlobalComponent(XSObject component, XSDDescription desc) {
        final String namespace = component.getNamespace();
        
        desc.setNamespace(namespace);
        final SchemaGrammar sg = getSchemaGrammar(desc);

        short componentType = component.getType();
        final String name = component.getName();

        switch (componentType) {
        case XSConstants.TYPE_DEFINITION :
            if (!((XSTypeDefinition) component).getAnonymous()) {
                if (sg.getGlobalTypeDecl(name) == null) {
                    sg.addGlobalTypeDecl((XSTypeDefinition) component);
                }
                // store the declaration in the extended map, using an empty location
                if (sg.getGlobalTypeDecl(name, "") == null) {
                    sg.addGlobalTypeDecl((XSTypeDefinition) component, "");
                }
            }
            break;
        case XSConstants.ATTRIBUTE_DECLARATION :
            if (((XSAttributeDecl) component).getScope() == XSAttributeDecl.SCOPE_GLOBAL) {
                if (sg.getGlobalAttributeDecl(name) == null) {
                    sg.addGlobalAttributeDecl((XSAttributeDecl) component);
                }
                // store the declaration in the extended map, using an empty location
                if (sg.getGlobalAttributeDecl(name, "") == null) {
                    sg.addGlobalAttributeDecl((XSAttributeDecl) component, "");
                }
            }
            break;
        case XSConstants.ATTRIBUTE_GROUP :
            if (sg.getGlobalAttributeDecl(name) == null) {
                sg.addGlobalAttributeGroupDecl((XSAttributeGroupDecl) component);
            }
            // store the declaration in the extended map, using an empty location
            if (sg.getGlobalAttributeDecl(name, "") == null) {
                sg.addGlobalAttributeGroupDecl((XSAttributeGroupDecl) component, "");
            }
            break;
        case XSConstants.ELEMENT_DECLARATION :
            if (((XSElementDecl) component).getScope() == XSElementDecl.SCOPE_GLOBAL) {
                sg.addGlobalElementDeclAll((XSElementDecl) component);

                if (sg.getGlobalElementDecl(name) == null) {
                    sg.addGlobalElementDecl((XSElementDecl) component);
                }
                // store the declaration in the extended map, using an empty location
                if (sg.getGlobalElementDecl(name, "") == null) {
                    sg.addGlobalElementDecl((XSElementDecl) component, "");
                }
            }
            break;
        case XSConstants.MODEL_GROUP_DEFINITION :
            if (sg.getGlobalGroupDecl(name) == null) {
                sg.addGlobalGroupDecl((XSGroupDecl) component);
            }
            // store the declaration in the extended map, using an empty location
            if (sg.getGlobalGroupDecl(name, "") == null) {
                sg.addGlobalGroupDecl((XSGroupDecl) component, "");
            }
            break;
        case XSConstants.NOTATION_DECLARATION :
            if (sg.getGlobalNotationDecl(name) == null) {
                sg.addGlobalNotationDecl((XSNotationDecl) component);
            }
            // store the declaration in the extended map, using an empty location
            if (sg.getGlobalNotationDecl(name, "") == null) {
                sg.addGlobalNotationDecl((XSNotationDecl) component, "");
            }
            break;
        case XSConstants.IDENTITY_CONSTRAINT :
        case XSConstants.ATTRIBUTE_USE :
        default :
            break;
        }
    }

    private void updateImportDependencies(Hashtable table) {
        Enumeration keys = table.keys();
        String namespace;
        Vector importList;
        while (keys.hasMoreElements()) {
            namespace = (String) keys.nextElement();
            importList = (Vector) table.get(null2EmptyString(namespace));
            if (importList.size() > 0) {
                expandImportList(namespace, importList);
            }
        }
    }
    
    private void expandImportList(String namespace, Vector namespaceList) {
        SchemaGrammar sg = fGrammarBucket.getGrammar(namespace);
        // shouldn't be null
        if (sg != null) {
            Vector isgs = sg.getImportedGrammars();
            if (isgs == null) {
                isgs = new Vector();
                addImportList(sg, isgs, namespaceList);
                sg.setImportedGrammars(isgs);
            }
            else {
                updateImportList(sg, isgs, namespaceList);
            }
        }
    }

    private void addImportList(SchemaGrammar sg, Vector importedGrammars, Vector namespaceList) {
        final int size = namespaceList.size();
        SchemaGrammar isg;

        for (int i=0; i<size; i++) {
            isg = fGrammarBucket.getGrammar((String)namespaceList.elementAt(i));
            if (isg != null) {
                importedGrammars.add(isg);
            }
            else {
                //REVIST: report an error message
            }
        }
    }

    private void updateImportList(SchemaGrammar sg, Vector importedGrammars, Vector namespaceList) {
        final int size = namespaceList.size();
        SchemaGrammar isg;

        for (int i=0; i<size; i++) {
            isg = fGrammarBucket.getGrammar((String)namespaceList.elementAt(i));
            if (isg != null) {
                if (!containedImportedGrammar(importedGrammars, isg)) {
                    importedGrammars.add(isg);
                }
            }
            else {
                //REVIST: report an error message
            }
        }
    }

    private boolean containedImportedGrammar(Vector importedGrammar, SchemaGrammar grammar) {
        final int size = importedGrammar.size();
        SchemaGrammar sg;

        for (int i=0; i<size; i++) {
            sg = (SchemaGrammar) importedGrammar.elementAt(i);
            if (null2EmptyString(sg.getTargetNamespace()).equals(null2EmptyString(grammar.getTargetNamespace()))) {
                return true;
            }
        }
        return false;
    }

    // NOTE: always assuming that fNamespaceGrowth is enabled
    //       otherwise the grammar should have existed
    private SchemaGrammar getSchemaGrammar(XSDDescription desc) {
        SchemaGrammar sg = findGrammar(desc, fNamespaceGrowth);

        if (sg == null) {
            sg = new SchemaGrammar(desc.getNamespace(), desc.makeClone(), fSymbolTable);
            fGrammarBucket.putGrammar(sg);
        }
        else if (sg.isImmutable()){
            sg = createGrammarFrom(sg);
        }

        return sg;
    }

    private Vector findDependentNamespaces(String namespace, Hashtable table) {
        final String ns = null2EmptyString(namespace);
        Vector namespaceList = (Vector) table.get(ns);
        
        if (namespaceList == null) {
            namespaceList = new Vector();
            table.put(ns, namespaceList);
        }
        
        return namespaceList;
    }

    private void addNamespaceDependency(String namespace1, String namespace2, Vector list) {
        final String ns1 = null2EmptyString(namespace1);
        final String ns2 = null2EmptyString(namespace2);
        if (!ns1.equals(ns2)) {
            if (!list.contains(ns2)) {
                list.add(ns2);
            }
        }
    }

    private void reportSharingError(String namespace, String name) {
        final String qName = (namespace == null)
            ? "," + name : namespace + "," + name;

        reportSchemaError("sch-props-correct.2", new Object [] {qName}, null);
    }

    // initialize all the traversers.
    // this should only need to be called once during the construction
    // of this object; it creates the traversers that will be used to
    
    // construct schemaGrammars.
    private void createTraversers() {
        fAttributeChecker = new XSAttributeChecker(this);
        fAttributeGroupTraverser = new XSDAttributeGroupTraverser(this, fAttributeChecker);
        fAttributeTraverser = new XSDAttributeTraverser(this, fAttributeChecker);
        fComplexTypeTraverser = new XSDComplexTypeTraverser(this, fAttributeChecker);
        fElementTraverser = new XSDElementTraverser(this, fAttributeChecker);
        fGroupTraverser = new XSDGroupTraverser(this, fAttributeChecker);
        fKeyrefTraverser = new XSDKeyrefTraverser(this, fAttributeChecker);
        fNotationTraverser = new XSDNotationTraverser(this, fAttributeChecker);
        fSimpleTypeTraverser = new XSDSimpleTypeTraverser(this, fAttributeChecker);
        fUniqueOrKeyTraverser = new XSDUniqueOrKeyTraverser(this, fAttributeChecker);
        fWildCardTraverser = new XSDWildcardTraverser(this, fAttributeChecker);
    } // createTraversers()
    
    // before parsing a schema, need to clear registries associated with
    // parsing schemas
    void prepareForParse() {
        fTraversed.clear();
        fDoc2SystemId.clear();
        fHiddenNodes.clear();
        fLastSchemaWasDuplicate = false;
    }

    // before traversing a schema's parse tree, need to reset all traversers and
    // clear all registries
    void prepareForTraverse() {
        fUnparsedAttributeRegistry.clear();
        fUnparsedAttributeGroupRegistry.clear();
        fUnparsedElementRegistry.clear();
        fUnparsedGroupRegistry.clear();
        fUnparsedIdentityConstraintRegistry.clear();
        fUnparsedNotationRegistry.clear();
        fUnparsedTypeRegistry.clear();
        
        fUnparsedAttributeRegistrySub.clear();
        fUnparsedAttributeGroupRegistrySub.clear();
        fUnparsedElementRegistrySub.clear();
        fUnparsedGroupRegistrySub.clear();
        fUnparsedIdentityConstraintRegistrySub.clear();
        fUnparsedNotationRegistrySub.clear();
        fUnparsedTypeRegistrySub.clear();

        for (int i=1; i<= TYPEDECL_TYPE; i++) {
            fUnparsedRegistriesExt[i].clear();
        }

        fXSDocumentInfoRegistry.clear();
        fDependencyMap.clear();
        fDoc2XSDocumentMap.clear();
        fRedefine2XSDMap.clear();
        fRedefine2NSSupport.clear();
        fAllTNSs.removeAllElements();
        fImportMap.clear();
        fRoot = null;
        
        // clear local element stack
        for (int i = 0; i < fLocalElemStackPos; i++) {
            fParticle[i] = null;
            fLocalElementDecl[i] = null;
            fLocalElementDecl_schema[i] = null;
            fLocalElemNamespaceContext[i] = null;
        }
        fLocalElemStackPos = 0;
        
        // and do same for keyrefs.
        for (int i = 0; i < fKeyrefStackPos; i++) {
            fKeyrefs[i] = null;
            fKeyrefElems[i] = null;
            fKeyrefNamespaceContext[i] = null;
            fKeyrefsMapXSDocumentInfo[i] = null;
        }
        fKeyrefStackPos = 0;
        
        // create traversers if necessary
        if (fAttributeChecker == null) {
            createTraversers();
        }
        
        // reset traversers
        Locale locale = fErrorReporter.getLocale();
        fAttributeChecker.reset(fSymbolTable);
        fAttributeGroupTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fAttributeTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fComplexTypeTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fElementTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fGroupTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fKeyrefTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fNotationTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fSimpleTypeTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fUniqueOrKeyTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        fWildCardTraverser.reset(fSymbolTable, fValidateAnnotations, locale);
        
        fRedefinedRestrictedAttributeGroupRegistry.clear();
        fRedefinedRestrictedGroupRegistry.clear();
        
        fGlobalAttrDecls.clear();
        fGlobalAttrGrpDecls.clear();
        fGlobalElemDecls.clear();
        fGlobalGroupDecls.clear();
        fGlobalNotationDecls.clear();
        fGlobalIDConstraintDecls.clear();
        fGlobalTypeDecls.clear();
    }
    public void setDeclPool (XSDeclarationPool declPool){
        fDeclPool = declPool;
    }
    public void setDVFactory(SchemaDVFactory dvFactory){
        fDVFactory = dvFactory;
    }
    
    public void reset(XMLComponentManager componentManager) {
        
        // set symbol table
        fSymbolTable = (SymbolTable) componentManager.getProperty(SYMBOL_TABLE);
        
        //set entity resolver
        fEntityResolver = (XMLEntityResolver) componentManager.getProperty(ENTITY_MANAGER);
        XMLEntityResolver er = (XMLEntityResolver)componentManager.getProperty(ENTITY_RESOLVER);
        if (er != null)
            fSchemaParser.setEntityResolver(er);
        
        // set error reporter
        fErrorReporter =
            (XMLErrorReporter) componentManager.getProperty(ERROR_REPORTER);
        try {
            XMLErrorHandler currErrorHandler = fErrorReporter.getErrorHandler();
            // Setting a parser property can be much more expensive
            // than checking its value.  Don't set the ERROR_HANDLER
            // or LOCALE properties unless they've actually changed.
            if (currErrorHandler != fSchemaParser.getProperty(ERROR_HANDLER)) {
                fSchemaParser.setProperty(ERROR_HANDLER, (currErrorHandler != null) ? currErrorHandler : new DefaultErrorHandler());
                if (fAnnotationValidator != null) {
                    fAnnotationValidator.setProperty(ERROR_HANDLER, (currErrorHandler != null) ? currErrorHandler : new DefaultErrorHandler());
            	}
            }
            Locale currentLocale = fErrorReporter.getLocale();
            if (currentLocale != fSchemaParser.getProperty(LOCALE)) {
                fSchemaParser.setProperty(LOCALE, currentLocale);
                if (fAnnotationValidator != null) {
                    fAnnotationValidator.setProperty(LOCALE, currentLocale);
                }
            }
        } 
        catch (XMLConfigurationException e) {}
        
        try {
            fValidateAnnotations = componentManager.getFeature(VALIDATE_ANNOTATIONS);
        } catch (XMLConfigurationException e) {
            fValidateAnnotations = false;
        }
        
        try {
            fHonourAllSchemaLocations = componentManager.getFeature(HONOUR_ALL_SCHEMALOCATIONS);
        } catch (XMLConfigurationException e) {
            fHonourAllSchemaLocations = false;
        }
        
        try {
            fNamespaceGrowth = componentManager.getFeature(NAMESPACE_GROWTH);
        } catch (XMLConfigurationException e) {
            fNamespaceGrowth = false;
        }

        try {
            fTolerateDuplicates = componentManager.getFeature(TOLERATE_DUPLICATES);
        } catch (XMLConfigurationException e) {
            fTolerateDuplicates = false;
        }

        try {
            fSchemaParser.setFeature(
                    CONTINUE_AFTER_FATAL_ERROR,
                    fErrorReporter.getFeature(CONTINUE_AFTER_FATAL_ERROR));
        } catch (XMLConfigurationException e) {
        }
        
        try {
            fSchemaParser.setFeature(
                    ALLOW_JAVA_ENCODINGS,
                    componentManager.getFeature(ALLOW_JAVA_ENCODINGS));
        } catch (XMLConfigurationException e) {
        }
        try {
            fSchemaParser.setFeature(
                    STANDARD_URI_CONFORMANT_FEATURE,
                    componentManager.getFeature(STANDARD_URI_CONFORMANT_FEATURE));
        } catch (XMLConfigurationException e) {
        }
        
        try {
            fGrammarPool =
                (XMLGrammarPool) componentManager.getProperty(XMLGRAMMAR_POOL);
        } catch (XMLConfigurationException e) {
            fGrammarPool = null;
        }
        // security features
        try {
            fSchemaParser.setFeature( DISALLOW_DOCTYPE,
                    componentManager.getFeature(DISALLOW_DOCTYPE));
        } catch (XMLConfigurationException e) {
        }
        try {
            Object security = componentManager.getProperty(SECURITY_MANAGER);
            if (security != null){
                fSchemaParser.setProperty(SECURITY_MANAGER, security);
            }
        } catch (XMLConfigurationException e) {
        }
        
    } // reset(XMLComponentManager)
    
    
    
Traverse all the deferred local elements. This method should be called
by traverseSchemas after we've done with all the global declarations.
/**
     * Traverse all the deferred local elements. This method should be called
     * by traverseSchemas after we've done with all the global declarations.
     */
    void traverseLocalElements() {
        fElementTraverser.fDeferTraversingLocalElements = false;
        
        for (int i = 0; i < fLocalElemStackPos; i++) {
            Element currElem = fLocalElementDecl[i];
            //XSDocumentInfo currSchema = (XSDocumentInfo)fDoc2XSDocumentMap.get(DOMUtil.getDocument(currElem));
            //XSDocumentInfo currSchema = (XSDocumentInfo)fDoc2XSDocumentMap.get(DOMUtil.getRoot(DOMUtil.getDocument(currElem)));
            XSDocumentInfo currSchema = fLocalElementDecl_schema[i];
            SchemaGrammar currGrammar = fGrammarBucket.getGrammar(currSchema.fTargetNamespace);
            fElementTraverser.traverseLocal (fParticle[i], currElem, currSchema, currGrammar, fAllContext[i], fParent[i], fLocalElemNamespaceContext[i]);
            // If it's an empty particle, remove it from the containing component.
            if (fParticle[i].fType == XSParticleDecl.PARTICLE_EMPTY) {
                XSModelGroupImpl group = null;
                if (fParent[i] instanceof XSComplexTypeDecl) {
                    XSParticle p = ((XSComplexTypeDecl)fParent[i]).getParticle();
                    if (p != null)
                        group = (XSModelGroupImpl)p.getTerm();
                }
                else {
                    group = ((XSGroupDecl)fParent[i]).fModelGroup;
                }
                if (group != null)
                    removeParticle(group, fParticle[i]);
            }
        }
    }
    
    private boolean removeParticle(XSModelGroupImpl group, XSParticleDecl particle) {
        XSParticleDecl member;
        for (int i = 0; i < group.fParticleCount; i++) {
            member = group.fParticles[i];
            if (member == particle) {
                for (int j = i; j < group.fParticleCount-1; j++)
                    group.fParticles[j] = group.fParticles[j+1];
                group.fParticleCount--;
                return true;
            }
            if (member.fType == XSParticleDecl.PARTICLE_MODELGROUP) {
                if (removeParticle((XSModelGroupImpl)member.fValue, particle))
                    return true;
            }
        }
        return false;
    }
    
    // the purpose of this method is to keep up-to-date structures
    // we'll need for the feferred traversal of local elements.
    void fillInLocalElemInfo(Element elmDecl,
            XSDocumentInfo schemaDoc,
            int allContextFlags,
            XSObject parent,
            XSParticleDecl particle) {
        
        // if the stack is full, increase the size
        if (fParticle.length == fLocalElemStackPos) {
            // increase size
            XSParticleDecl[] newStackP = new XSParticleDecl[fLocalElemStackPos+INC_STACK_SIZE];
            System.arraycopy(fParticle, 0, newStackP, 0, fLocalElemStackPos);
            fParticle = newStackP;
            Element[] newStackE = new Element[fLocalElemStackPos+INC_STACK_SIZE];
            System.arraycopy(fLocalElementDecl, 0, newStackE, 0, fLocalElemStackPos);
            fLocalElementDecl = newStackE;
            XSDocumentInfo [] newStackE_schema = new XSDocumentInfo[fLocalElemStackPos+INC_STACK_SIZE];
            System.arraycopy(fLocalElementDecl_schema, 0, newStackE_schema, 0, fLocalElemStackPos);
            fLocalElementDecl_schema = newStackE_schema;
            int[] newStackI = new int[fLocalElemStackPos+INC_STACK_SIZE];
            System.arraycopy(fAllContext, 0, newStackI, 0, fLocalElemStackPos);
            fAllContext = newStackI;
            XSObject[] newStackC = new XSObject[fLocalElemStackPos+INC_STACK_SIZE];
            System.arraycopy(fParent, 0, newStackC, 0, fLocalElemStackPos);
            fParent = newStackC;
            String [][] newStackN = new String [fLocalElemStackPos+INC_STACK_SIZE][];
            System.arraycopy(fLocalElemNamespaceContext, 0, newStackN, 0, fLocalElemStackPos);
            fLocalElemNamespaceContext = newStackN;
        }
        
        fParticle[fLocalElemStackPos] = particle;
        fLocalElementDecl[fLocalElemStackPos] = elmDecl;
        fLocalElementDecl_schema[fLocalElemStackPos] = schemaDoc;
        fAllContext[fLocalElemStackPos] = allContextFlags;
        fParent[fLocalElemStackPos] = parent;
        fLocalElemNamespaceContext[fLocalElemStackPos++] = schemaDoc.fNamespaceSupport.getEffectiveLocalContext();
    } // end fillInLocalElemInfo(...)

    
This method makes sure that
if this component is being redefined that it lives in the
right schema.  It then renames the component correctly.  If it
detects a collision--a duplicate definition--then it complains.
Note that redefines must be handled carefully:  if there
is a collision, it may be because we're redefining something we know about
or because we've found the thing we're redefining.
/** This method makes sure that
     * if this component is being redefined that it lives in the
     * right schema.  It then renames the component correctly.  If it
     * detects a collision--a duplicate definition--then it complains.
     * Note that redefines must be handled carefully:  if there
     * is a collision, it may be because we're redefining something we know about
     * or because we've found the thing we're redefining.
     */
    void checkForDuplicateNames(String qName, int declType,
            Hashtable registry, Hashtable registry_sub, Element currComp,
            XSDocumentInfo currSchema) {
        Object objElem = null;
        // REVISIT:  when we add derivation checking, we'll have to make
        // sure that ID constraint collisions don't necessarily result in error messages.
        if ((objElem = registry.get(qName)) == null) {
            // need to check whether we have a global declaration in the corresponding
            // grammar
            if (fNamespaceGrowth && !fTolerateDuplicates) {
                checkForDuplicateNames(qName, declType, currComp);
            }
            // just add it in!
            registry.put(qName, currComp);
            registry_sub.put(qName, currSchema);
        }
        else {
            Element collidingElem = (Element)objElem;
            XSDocumentInfo collidingElemSchema = (XSDocumentInfo)registry_sub.get(qName);
            if (collidingElem == currComp) return;
            Element elemParent = null;
            XSDocumentInfo redefinedSchema = null;
            // case where we've collided with a redefining element
            // (the parent of the colliding element is a redefine)
            boolean collidedWithRedefine = true;
            if ((DOMUtil.getLocalName((elemParent = DOMUtil.getParent(collidingElem))).equals(SchemaSymbols.ELT_REDEFINE))) {
                redefinedSchema = (XSDocumentInfo)(fRedefine2XSDMap.get(elemParent));
                // case where we're a redefining element.
            }
            else if ((DOMUtil.getLocalName(DOMUtil.getParent(currComp)).equals(SchemaSymbols.ELT_REDEFINE))) {
                redefinedSchema = collidingElemSchema;
                collidedWithRedefine = false;
            }
            if (redefinedSchema != null) { //redefinition involved somehow
                // If both components belong to the same document then
                // report an error and return.
                if(collidingElemSchema == currSchema){
                    reportSchemaError("sch-props-correct.2", new Object[]{qName}, currComp);
                    return;
                }
                
                String newName = qName.substring(qName.lastIndexOf(',')+1)+REDEF_IDENTIFIER;
                if (redefinedSchema == currSchema) { // object comp. okay here
                    // now have to do some renaming...
                    currComp.setAttribute(SchemaSymbols.ATT_NAME, newName);
                    if (currSchema.fTargetNamespace == null){
                        registry.put(","+newName, currComp);
                        registry_sub.put(","+newName, currSchema);
                    }
                    else{
                        registry.put(currSchema.fTargetNamespace+","+newName, currComp);
                        registry_sub.put(currSchema.fTargetNamespace+","+newName, currSchema);
                    }
                    // and take care of nested redefines by calling recursively:
                    if (currSchema.fTargetNamespace == null)
                        checkForDuplicateNames(","+newName, declType, registry, registry_sub, currComp, currSchema);
                    else
                        checkForDuplicateNames(currSchema.fTargetNamespace+","+newName, declType, registry, registry_sub, currComp, currSchema);
                }
                else { // we may be redefining the wrong schema
                    if (collidedWithRedefine) {
                        if (currSchema.fTargetNamespace == null)
                            checkForDuplicateNames(","+newName, declType, registry, registry_sub, currComp, currSchema);
                        else
                            checkForDuplicateNames(currSchema.fTargetNamespace+","+newName, declType, registry, registry_sub, currComp, currSchema);
                    }
                    else {
                        // error that redefined element in wrong schema
                        reportSchemaError("sch-props-correct.2", new Object [] {qName}, currComp);
                    }
                }
            }
            else {
                // we've just got a flat-out collision (we tolerate duplicate
                // declarations, only if they are defined in different schema
                // documents)
                if (!fTolerateDuplicates || fUnparsedRegistriesExt[declType].get(qName) == currSchema) {
                    reportSchemaError("sch-props-correct.2", new Object []{qName}, currComp);
                }
            }
        }

        // store the lastest current document info
        if (fTolerateDuplicates) {
            fUnparsedRegistriesExt[declType].put(qName, currSchema);
        }

    } // checkForDuplicateNames(String, Hashtable, Element, XSDocumentInfo):void

    void checkForDuplicateNames(String qName, int declType, Element currComp) {
        int namespaceEnd = qName.indexOf(',');
        String namespace = qName.substring(0, namespaceEnd);
        SchemaGrammar grammar = fGrammarBucket.getGrammar(emptyString2Null(namespace));
        
        if (grammar != null) {
            Object obj = getGlobalDeclFromGrammar(grammar, declType, qName.substring(namespaceEnd + 1));
            if (obj != null) {
                reportSchemaError("sch-props-correct.2", new Object []{qName}, currComp);
            }
        }
    }
    
    // the purpose of this method is to take the component of the
    // specified type and rename references to itself so that they
    // refer to the object being redefined.  It takes special care of
    // <group>s and <attributeGroup>s to ensure that information
    // relating to implicit restrictions is preserved for those
    // traversers.
    private void renameRedefiningComponents(XSDocumentInfo currSchema,
            Element child, String componentType,
            String oldName, String newName) {
        if (componentType.equals(SchemaSymbols.ELT_SIMPLETYPE)) {
            Element grandKid = DOMUtil.getFirstChildElement(child);
            if (grandKid == null) {
                reportSchemaError("src-redefine.5.a.a", null, child);
            }
            else {
                String grandKidName = DOMUtil.getLocalName(grandKid);
                if (grandKidName.equals(SchemaSymbols.ELT_ANNOTATION)) {
                    grandKid = DOMUtil.getNextSiblingElement(grandKid);
                }
                if (grandKid == null) {
                    reportSchemaError("src-redefine.5.a.a", null, child);
                }
                else {
                    grandKidName = DOMUtil.getLocalName(grandKid);
                    if (!grandKidName.equals(SchemaSymbols.ELT_RESTRICTION)) {
                        reportSchemaError("src-redefine.5.a.b", new Object[]{grandKidName}, child);
                    }
                    else {
                        Object[] attrs = fAttributeChecker.checkAttributes(grandKid, false, currSchema);
                        QName derivedBase = (QName)attrs[XSAttributeChecker.ATTIDX_BASE];
                        if (derivedBase == null ||
                                derivedBase.uri != currSchema.fTargetNamespace ||
                                !derivedBase.localpart.equals(oldName)) {
                            reportSchemaError("src-redefine.5.a.c",
                                    new Object[]{grandKidName,
                                    (currSchema.fTargetNamespace==null?"":currSchema.fTargetNamespace)
                                    + "," + oldName},
                                    child);
                        }
                        else {
                            // now we have to do the renaming...
                            if (derivedBase.prefix != null && derivedBase.prefix.length() > 0)
                                grandKid.setAttribute( SchemaSymbols.ATT_BASE,
                                        derivedBase.prefix + ":" + newName );
                            else
                                grandKid.setAttribute( SchemaSymbols.ATT_BASE, newName );
                            //                            return true;
                        }
                        fAttributeChecker.returnAttrArray(attrs, currSchema);
                    }
                }
            }
        }
        else if (componentType.equals(SchemaSymbols.ELT_COMPLEXTYPE)) {
            Element grandKid = DOMUtil.getFirstChildElement(child);
            if (grandKid == null) {
                reportSchemaError("src-redefine.5.b.a", null, child);
            }
            else {
                if (DOMUtil.getLocalName(grandKid).equals(SchemaSymbols.ELT_ANNOTATION)) {
                    grandKid = DOMUtil.getNextSiblingElement(grandKid);
                }
                if (grandKid == null) {
                    reportSchemaError("src-redefine.5.b.a", null, child);
                }
                else {
                    // have to go one more level down; let another pass worry whether complexType is valid.
                    Element greatGrandKid = DOMUtil.getFirstChildElement(grandKid);
                    if (greatGrandKid == null) {
                        reportSchemaError("src-redefine.5.b.b", null, grandKid);
                    }
                    else {
                        String greatGrandKidName = DOMUtil.getLocalName(greatGrandKid);
                        if (greatGrandKidName.equals(SchemaSymbols.ELT_ANNOTATION)) {
                            greatGrandKid = DOMUtil.getNextSiblingElement(greatGrandKid);
                        }
                        if (greatGrandKid == null) {
                            reportSchemaError("src-redefine.5.b.b", null, grandKid);
                        }
                        else {
                            greatGrandKidName = DOMUtil.getLocalName(greatGrandKid);
                            if (!greatGrandKidName.equals(SchemaSymbols.ELT_RESTRICTION) &&
                                    !greatGrandKidName.equals(SchemaSymbols.ELT_EXTENSION)) {
                                reportSchemaError("src-redefine.5.b.c", new Object[]{greatGrandKidName}, greatGrandKid);
                            }
                            else {
                                Object[] attrs = fAttributeChecker.checkAttributes(greatGrandKid, false, currSchema);
                                QName derivedBase = (QName)attrs[XSAttributeChecker.ATTIDX_BASE];
                                if (derivedBase == null ||
                                        derivedBase.uri != currSchema.fTargetNamespace ||
                                        !derivedBase.localpart.equals(oldName)) {
                                    reportSchemaError("src-redefine.5.b.d",
                                            new Object[]{greatGrandKidName,
                                            (currSchema.fTargetNamespace==null?"":currSchema.fTargetNamespace)
                                            + "," + oldName},
                                            greatGrandKid);
                                }
                                else {
                                    // now we have to do the renaming...
                                    if (derivedBase.prefix != null && derivedBase.prefix.length() > 0)
                                        greatGrandKid.setAttribute( SchemaSymbols.ATT_BASE,
                                                derivedBase.prefix + ":" + newName );
                                    else
                                        greatGrandKid.setAttribute( SchemaSymbols.ATT_BASE,
                                                newName );
                                    //                                    return true;
                                }
                            }
                        }
                    }
                }
            }
        }
        else if (componentType.equals(SchemaSymbols.ELT_ATTRIBUTEGROUP)) {
            String processedBaseName = (currSchema.fTargetNamespace == null)?
                    ","+oldName:currSchema.fTargetNamespace+","+oldName;
            int attGroupRefsCount = changeRedefineGroup(processedBaseName, componentType, newName, child, currSchema);
            if (attGroupRefsCount > 1) {
                reportSchemaError("src-redefine.7.1", new Object []{new Integer(attGroupRefsCount)}, child);
            }
            else if (attGroupRefsCount == 1) {
                //                return true;
            }
            else
                if (currSchema.fTargetNamespace == null)
                    fRedefinedRestrictedAttributeGroupRegistry.put(processedBaseName, ","+newName);
                else
                    fRedefinedRestrictedAttributeGroupRegistry.put(processedBaseName, currSchema.fTargetNamespace+","+newName);
        }
        else if (componentType.equals(SchemaSymbols.ELT_GROUP)) {
            String processedBaseName = (currSchema.fTargetNamespace == null)?
                    ","+oldName:currSchema.fTargetNamespace+","+oldName;
            int groupRefsCount = changeRedefineGroup(processedBaseName, componentType, newName, child, currSchema);
            if (groupRefsCount > 1) {
                reportSchemaError("src-redefine.6.1.1", new Object []{new Integer(groupRefsCount)}, child);
            }
            else if (groupRefsCount == 1) {
                //                return true;
            }
            else {
                if (currSchema.fTargetNamespace == null)
                    fRedefinedRestrictedGroupRegistry.put(processedBaseName, ","+newName);
                else
                    fRedefinedRestrictedGroupRegistry.put(processedBaseName, currSchema.fTargetNamespace+","+newName);
            }
        }
        else {
            reportSchemaError("Internal-Error", new Object [] {"could not handle this particular <redefine>; please submit your schemas and instance document in a bug report!"}, child);
        }
        // if we get here then we must have reported an error and failed somewhere...
        //        return false;
    } // renameRedefiningComponents(XSDocumentInfo, Element, String, String, String):void
    
    // this method takes a name of the form a:b, determines the URI mapped
    // to by a in the current SchemaNamespaceSupport object, and returns this
    // information in the form (nsURI,b) suitable for lookups in the global
    // decl Hashtables.
    // REVISIT: should have it return QName, instead of String. this would
    //          save lots of string concatenation time. we can use
    //          QName#equals() to compare two QNames, and use QName directly
    //          as a key to the SymbolHash.
    //          And when the DV's are ready to return compiled values from
    //          validate() method, we should just call QNameDV.validate()
    //          in this method.
    private String findQName(String name, XSDocumentInfo schemaDoc) {
        SchemaNamespaceSupport currNSMap = schemaDoc.fNamespaceSupport;
        int colonPtr = name.indexOf(':');
        String prefix = XMLSymbols.EMPTY_STRING;
        if (colonPtr > 0)
            prefix = name.substring(0, colonPtr);
        String uri = currNSMap.getURI(fSymbolTable.addSymbol(prefix));
        String localpart = (colonPtr == 0)?name:name.substring(colonPtr+1);
        if (prefix == XMLSymbols.EMPTY_STRING && uri == null && schemaDoc.fIsChameleonSchema)
            uri = schemaDoc.fTargetNamespace;
        if (uri == null)
            return ","+localpart;
        return uri+","+localpart;
    } // findQName(String, XSDocumentInfo):  String
    
    // This function looks among the children of curr for an element of type elementSought.
    // If it finds one, it evaluates whether its ref attribute contains a reference
    // to originalQName.  If it does, it returns 1 + the value returned by
    // calls to itself on all other children.  In all other cases it returns 0 plus
    // the sum of the values returned by calls to itself on curr's children.
    // It also resets the value of ref so that it will refer to the renamed type from the schema
    // being redefined.
    private int changeRedefineGroup(String originalQName, String elementSought,
            String newName, Element curr, XSDocumentInfo schemaDoc) {
        int result = 0;
        for (Element child = DOMUtil.getFirstChildElement(curr);
        child != null; child = DOMUtil.getNextSiblingElement(child)) {
            String name = DOMUtil.getLocalName(child);
            if (!name.equals(elementSought))
                result += changeRedefineGroup(originalQName, elementSought, newName, child, schemaDoc);
            else {
                String ref = child.getAttribute( SchemaSymbols.ATT_REF );
                if (ref.length() != 0) {
                    String processedRef = findQName(ref, schemaDoc);
                    if (originalQName.equals(processedRef)) {
                        String prefix = XMLSymbols.EMPTY_STRING;
                        int colonptr = ref.indexOf(":");
                        if (colonptr > 0) {
                            prefix = ref.substring(0,colonptr);
                            child.setAttribute(SchemaSymbols.ATT_REF, prefix + ":" + newName);
                        }
                        else
                            child.setAttribute(SchemaSymbols.ATT_REF, newName);
                        result++;
                        if (elementSought.equals(SchemaSymbols.ELT_GROUP)) {
                            String minOccurs = child.getAttribute( SchemaSymbols.ATT_MINOCCURS );
                            String maxOccurs = child.getAttribute( SchemaSymbols.ATT_MAXOCCURS );
                            if (!((maxOccurs.length() == 0 || maxOccurs.equals("1"))
                                    && (minOccurs.length() == 0 || minOccurs.equals("1")))) {
                                reportSchemaError("src-redefine.6.1.2", new Object [] {ref}, child);
                            }
                        }
                    }
                } // if ref was null some other stage of processing will flag the error
            }
        }
        return result;
    } // changeRedefineGroup
    
    // this method returns the XSDocumentInfo object that contains the
    // component corresponding to decl.  If components from this
    // document cannot be referred to from those of currSchema, this
    // method returns null; it's up to the caller to throw an error.
    // @param:  currSchema:  the XSDocumentInfo object containing the
    // decl ref'ing us.
    // @param:  decl:  the declaration being ref'd.
    // this method is superficial now. ---Jack
    private XSDocumentInfo findXSDocumentForDecl(XSDocumentInfo currSchema,
            Element decl, XSDocumentInfo decl_Doc) {
        
        if (DEBUG_NODE_POOL) {
            System.out.println("DOCUMENT NS:"+ currSchema.fTargetNamespace+" hashcode:"+ ((Object)currSchema.fSchemaElement).hashCode());
        }
        Object temp = decl_Doc;
        if (temp == null) {
            // something went badly wrong; we don't know this doc?
            return null;
        }
        XSDocumentInfo declDocInfo = (XSDocumentInfo)temp;
        return declDocInfo;
        /*********
         Logic here is unnecessary after schema WG's recent decision to allow
         schema components from one document to refer to components of any other,
         so long as there's some include/import/redefine path amongst them.
         If they rver reverse this decision the code's right here though...  - neilg
         // now look in fDependencyMap to see if this is reachable
          if(((Vector)fDependencyMap.get(currSchema)).contains(declDocInfo)) {
          return declDocInfo;
          }
          // obviously the requesting doc didn't include, redefine or
           // import the one containing decl...
            return null;
            **********/
    } // findXSDocumentForDecl(XSDocumentInfo, Element):  XSDocumentInfo
    
    // returns whether more than <annotation>s occur in children of elem
    private boolean nonAnnotationContent(Element elem) {
        for(Element child = DOMUtil.getFirstChildElement(elem); child != null; child = DOMUtil.getNextSiblingElement(child)) {
            if(!(DOMUtil.getLocalName(child).equals(SchemaSymbols.ELT_ANNOTATION))) return true;
        }
        return false;
    } // nonAnnotationContent(Element):  boolean
    
    private void setSchemasVisible(XSDocumentInfo startSchema) {
        if (DOMUtil.isHidden(startSchema.fSchemaElement, fHiddenNodes)) {
            // make it visible
            DOMUtil.setVisible(startSchema.fSchemaElement, fHiddenNodes);           
            Vector dependingSchemas = (Vector)fDependencyMap.get(startSchema);
            for (int i = 0; i < dependingSchemas.size(); i++) {
                setSchemasVisible((XSDocumentInfo)dependingSchemas.elementAt(i));
            }
        }
        // if it's visible already than so must be its children
    } // setSchemasVisible(XSDocumentInfo): void
    
    private SimpleLocator xl = new SimpleLocator();
    
    
Extract location information from an Element node, and create a
new SimpleLocator object from such information. Returning null means
no information can be retrieved from the element.
/**
     * Extract location information from an Element node, and create a
     * new SimpleLocator object from such information. Returning null means
     * no information can be retrieved from the element.
     */
    public SimpleLocator element2Locator(Element e) {
        if (!( e instanceof ElementImpl))
            return null;
        
        SimpleLocator l = new SimpleLocator();
        return element2Locator(e, l) ? l : null;
    }
    
    
Extract location information from an Element node, store such
information in the passed-in SimpleLocator object, then return
true. Returning false means can't extract or store such information.
/**
     * Extract location information from an Element node, store such
     * information in the passed-in SimpleLocator object, then return
     * true. Returning false means can't extract or store such information.
     */
    public boolean element2Locator(Element e, SimpleLocator l) {
        if (l == null)
            return false;
        if (e instanceof ElementImpl) {
            ElementImpl ele = (ElementImpl)e;
            // get system id from document object
            Document doc = ele.getOwnerDocument();
            String sid = (String)fDoc2SystemId.get(DOMUtil.getRoot(doc));
            // line/column numbers are stored in the element node
            int line = ele.getLineNumber();
            int column = ele.getColumnNumber();
            l.setValues(sid, sid, line, column, ele.getCharacterOffset());
            return true;
        }
        return false;
    }
    
    void reportSchemaError(String key, Object[] args, Element ele) {
        reportSchemaError(key, args, ele, null);
    }
    
    void reportSchemaError(String key, Object[] args, Element ele, Exception exception) {
        if (element2Locator(ele, xl)) {
            fErrorReporter.reportError(xl, XSMessageFormatter.SCHEMA_DOMAIN,
                    key, args, XMLErrorReporter.SEVERITY_ERROR, exception);
        }
        else {
            fErrorReporter.reportError(XSMessageFormatter.SCHEMA_DOMAIN,
                    key, args, XMLErrorReporter.SEVERITY_ERROR, exception);
        }
    }
    
    void reportSchemaWarning(String key, Object[] args, Element ele) {
        reportSchemaWarning(key, args, ele, null);
    }
    
    void reportSchemaWarning(String key, Object[] args, Element ele, Exception exception) {
        if (element2Locator(ele, xl)) {
            fErrorReporter.reportError(xl, XSMessageFormatter.SCHEMA_DOMAIN,
                    key, args, XMLErrorReporter.SEVERITY_WARNING, exception);
        }
        else {
            fErrorReporter.reportError(XSMessageFormatter.SCHEMA_DOMAIN,
                    key, args, XMLErrorReporter.SEVERITY_WARNING, exception);
        }
    }
    
    
Grammar pool used for validating annotations. This will return all of the
grammars from the grammar bucket. It will also return an object for the
schema for schemas which will contain at least the relevant declarations
for annotations.
/**
     * Grammar pool used for validating annotations. This will return all of the
     * grammars from the grammar bucket. It will also return an object for the
     * schema for schemas which will contain at least the relevant declarations
     * for annotations.
     */
    private static class XSAnnotationGrammarPool implements XMLGrammarPool {
        
        private XSGrammarBucket fGrammarBucket;
        private Grammar [] fInitialGrammarSet;
        
        public Grammar[] retrieveInitialGrammarSet(String grammarType) {
            if (grammarType == XMLGrammarDescription.XML_SCHEMA) {
                if (fInitialGrammarSet == null) {
                    if (fGrammarBucket == null) {
                        fInitialGrammarSet = new Grammar [] {SchemaGrammar.Schema4Annotations.INSTANCE};
                    }
                    else {
                        SchemaGrammar [] schemaGrammars = fGrammarBucket.getGrammars();
                        /** 
                         * If the grammar bucket already contains the schema for schemas
                         * then we already have the definitions for the parts relevant
                         * to annotations.
                         */
                        for (int i = 0; i < schemaGrammars.length; ++i) {
                            if (SchemaSymbols.URI_SCHEMAFORSCHEMA.equals(schemaGrammars[i].getTargetNamespace())) {
                                fInitialGrammarSet = schemaGrammars;
                                return fInitialGrammarSet;
                            }
                        }
                        Grammar [] grammars = new Grammar[schemaGrammars.length + 1];
                        System.arraycopy(schemaGrammars, 0, grammars, 0, schemaGrammars.length);
                        grammars[grammars.length - 1] = SchemaGrammar.Schema4Annotations.INSTANCE;
                        fInitialGrammarSet = grammars;
                    }
                }
                return fInitialGrammarSet;
            }
            return new Grammar[0];
        }

        public void cacheGrammars(String grammarType, Grammar[] grammars) {
            
        }

        public Grammar retrieveGrammar(XMLGrammarDescription desc) {
            if (desc.getGrammarType() == XMLGrammarDescription.XML_SCHEMA) {
                final String tns = ((XMLSchemaDescription) desc).getTargetNamespace();
                if (fGrammarBucket != null) {
                    Grammar grammar = fGrammarBucket.getGrammar(tns);
                    if (grammar != null) {
                        return grammar;
                    }
                }
                if (SchemaSymbols.URI_SCHEMAFORSCHEMA.equals(tns)) {
                    return SchemaGrammar.Schema4Annotations.INSTANCE;
                }
            }
            return null;
        }
        
        public void refreshGrammars(XSGrammarBucket gBucket) {
            fGrammarBucket = gBucket;
            fInitialGrammarSet = null;
        }

        public void lockPool() {}

        public void unlockPool() {}

        public void clear() {}
    }

    
used to identify a reference to a schema document
if the same document is referenced twice with the same key, then
we only need to parse it once.
When 2 XSDKey's are compared, the following table can be used to
determine whether they are equal:
     inc     red     imp     pre     ins
inc  N/L      ?      N/L     N/L     N/L
red   ?      N/L      ?       ?       ?
imp  N/L      ?      N/P     N/P     N/P
pre  N/L      ?      N/P     N/P     N/P
ins  N/L      ?      N/P     N/P     N/P
Where: N/L: duplicate when they have the same namespace and location.
        ? : not clear from the spec.
            REVISIT: to simplify the process, also considering
            it's very rare, we treat them as not duplicate.
       N/P: not possible. imp/pre/ins are referenced by namespace.
            when the first time we encounter a schema document for a
            namespace, we create a grammar and store it in the grammar
            bucket. when we see another reference to the same namespace,
            we first check whether a grammar with the same namespace is
            already in the bucket, which is true in this case, so we
            won't create another XSDKey.
Conclusion from the table: two XSDKey's are duplicate only when all of
the following are true:
1. They are both "redefine", or neither is "redefine";
2. They have the same namespace;
3. They have the same non-null location.
About 3: if neither has a non-null location, then it's the case where
2 input streams are provided, but no system ID is provided. We can't tell
whether the 2 streams have the same content, so we treat them as not
duplicate.
/**
     * used to identify a reference to a schema document
     * if the same document is referenced twice with the same key, then
     * we only need to parse it once.
     *
     * When 2 XSDKey's are compared, the following table can be used to
     * determine whether they are equal:
     *      inc     red     imp     pre     ins
     * inc  N/L      ?      N/L     N/L     N/L
     * red   ?      N/L      ?       ?       ?
     * imp  N/L      ?      N/P     N/P     N/P
     * pre  N/L      ?      N/P     N/P     N/P
     * ins  N/L      ?      N/P     N/P     N/P
     *
     * Where: N/L: duplicate when they have the same namespace and location.
     *         ? : not clear from the spec.
     *             REVISIT: to simplify the process, also considering
     *             it's very rare, we treat them as not duplicate.
     *        N/P: not possible. imp/pre/ins are referenced by namespace.
     *             when the first time we encounter a schema document for a
     *             namespace, we create a grammar and store it in the grammar
     *             bucket. when we see another reference to the same namespace,
     *             we first check whether a grammar with the same namespace is
     *             already in the bucket, which is true in this case, so we
     *             won't create another XSDKey.
     *
     * Conclusion from the table: two XSDKey's are duplicate only when all of
     * the following are true:
     * 1. They are both "redefine", or neither is "redefine";
     * 2. They have the same namespace;
     * 3. They have the same non-null location.
     *
     * About 3: if neither has a non-null location, then it's the case where
     * 2 input streams are provided, but no system ID is provided. We can't tell
     * whether the 2 streams have the same content, so we treat them as not
     * duplicate.
     */
    private static class XSDKey {
        String systemId;
        short  referType;
        // for inclue/redefine, this is the enclosing namespace
        // for import/preparse/instance, this is the target namespace
        String referNS;
        
        XSDKey(String systemId, short referType, String referNS) {
            this.systemId = systemId;
            this.referType = referType;
            this.referNS = referNS;
        }
        
        public int hashCode() {
            // according to the description at the beginning of this class,
            // we use the hashcode of the namespace as the hashcoe of this key.
            return referNS == null ? 0 : referNS.hashCode();
        }
        
        public boolean equals(Object obj) {
            if (!(obj instanceof XSDKey)) {
                return false;
            }
            XSDKey key = (XSDKey)obj;
            
            // condition 1: both are redefine
            /** if (referType == XSDDescription.CONTEXT_REDEFINE ||
                    key.referType == XSDDescription.CONTEXT_REDEFINE) {
                if (referType != key.referType)
                    return false;
            }**/
            
            // condition 2: same namespace
            if (referNS != key.referNS)
                return false;
            
            // condition 3: same non-null location
            if (systemId == null || !systemId.equals(key.systemId)) {
                return false;
            }
            
            return true;
        }
    }
    
    private static final class SAX2XNIUtil extends ErrorHandlerWrapper {
        public static XMLParseException createXMLParseException0(SAXParseException exception) {
            return createXMLParseException(exception);
        }
        public static XNIException createXNIException0(SAXException exception) {
            return createXNIException(exception);
        }
    }
    
    
Params:
state – /**
     * @param state
     */
    public void setGenerateSyntheticAnnotations(boolean state) {
        fSchemaParser.setFeature(GENERATE_SYNTHETIC_ANNOTATIONS, state);
    }
    
} // XSDHandler