/*
 * 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.parsers;

import java.io.StringReader;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Stack;
import java.util.StringTokenizer;

import org.apache.xerces.dom.DOMErrorImpl;
import org.apache.xerces.dom.DOMMessageFormatter;
import org.apache.xerces.dom.DOMStringListImpl;
import org.apache.xerces.impl.Constants;
import org.apache.xerces.util.DOMEntityResolverWrapper;
import org.apache.xerces.util.DOMErrorHandlerWrapper;
import org.apache.xerces.util.DOMUtil;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.XMLSymbols;
import org.apache.xerces.xni.Augmentations;
import org.apache.xerces.xni.NamespaceContext;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XMLAttributes;
import org.apache.xerces.xni.XMLDTDContentModelHandler;
import org.apache.xerces.xni.XMLDTDHandler;
import org.apache.xerces.xni.XMLDocumentHandler;
import org.apache.xerces.xni.XMLLocator;
import org.apache.xerces.xni.XMLResourceIdentifier;
import org.apache.xerces.xni.XMLString;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.grammars.XMLGrammarPool;
import org.apache.xerces.xni.parser.XMLConfigurationException;
import org.apache.xerces.xni.parser.XMLDTDContentModelSource;
import org.apache.xerces.xni.parser.XMLDTDSource;
import org.apache.xerces.xni.parser.XMLDocumentSource;
import org.apache.xerces.xni.parser.XMLEntityResolver;
import org.apache.xerces.xni.parser.XMLInputSource;
import org.apache.xerces.xni.parser.XMLParseException;
import org.apache.xerces.xni.parser.XMLParserConfiguration;
import org.w3c.dom.DOMConfiguration;
import org.w3c.dom.DOMError;
import org.w3c.dom.DOMErrorHandler;
import org.w3c.dom.DOMException;
import org.w3c.dom.DOMStringList;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.ls.LSException;
import org.w3c.dom.ls.LSInput;
import org.w3c.dom.ls.LSParser;
import org.w3c.dom.ls.LSParserFilter;
import org.w3c.dom.ls.LSResourceResolver;
import org.w3c.dom.traversal.NodeFilter;

This is Xerces DOM Builder class. It uses the abstract DOM
parser with a document scanner, a dtd scanner, and a validator, as
well as a grammar pool.
Author:
Pavani Mukthipudi, Sun Microsystems Inc., Elena Litani, IBM, Rahul Srivastava, Sun Microsystems Inc.
Version:
$Id: DOMParserImpl.java 784915 2009-06-15 18:54:11Z knoaman $/**
 * This is Xerces DOM Builder class. It uses the abstract DOM
 * parser with a document scanner, a dtd scanner, and a validator, as
 * well as a grammar pool.
 *
 * @author Pavani Mukthipudi, Sun Microsystems Inc.
 * @author Elena Litani, IBM
 * @author Rahul Srivastava, Sun Microsystems Inc.
 * @version $Id: DOMParserImpl.java 784915 2009-06-15 18:54:11Z knoaman $
 */
public class DOMParserImpl
    extends AbstractDOMParser implements LSParser, DOMConfiguration {

    // SAX & Xerces feature ids

    
Feature identifier: namespaces. /** Feature identifier: namespaces. */
    protected static final String NAMESPACES =
        Constants.SAX_FEATURE_PREFIX + Constants.NAMESPACES_FEATURE;

    
Feature id: validation. /** Feature id: validation. */
    protected static final String VALIDATION_FEATURE =
        Constants.SAX_FEATURE_PREFIX+Constants.VALIDATION_FEATURE;

    
XML Schema validation /** XML Schema validation */
    protected static final String XMLSCHEMA =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_VALIDATION_FEATURE;
    
    
XML Schema full checking /** XML Schema full checking */
    protected static final String XMLSCHEMA_FULL_CHECKING =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_FULL_CHECKING;    

    
Dynamic validation /** Dynamic validation */
    protected static final String DYNAMIC_VALIDATION =
        Constants.XERCES_FEATURE_PREFIX + Constants.DYNAMIC_VALIDATION_FEATURE;

    
Feature identifier: expose schema normalized value /** Feature identifier: expose schema normalized value */
    protected static final String NORMALIZE_DATA =
        Constants.XERCES_FEATURE_PREFIX + Constants.SCHEMA_NORMALIZED_VALUE;

    
Feature identifier: disallow docType Decls. /** Feature identifier: disallow docType Decls. */
    protected static final String DISALLOW_DOCTYPE_DECL_FEATURE =
        Constants.XERCES_FEATURE_PREFIX + Constants.DISALLOW_DOCTYPE_DECL_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;

    // internal properties
    protected static final String SYMBOL_TABLE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY;

    protected static final String PSVI_AUGMENT =
        Constants.XERCES_FEATURE_PREFIX +Constants.SCHEMA_AUGMENT_PSVI;

    //
    // Data
    //

    
Include namespace declaration attributes in the document. /** Include namespace declaration attributes in the document. **/
    protected boolean fNamespaceDeclarations = true;

    // REVISIT: this value should be null by default and should be set during creation of
    //          LSParser
    protected String fSchemaType = null;

    protected boolean fBusy = false;

    private boolean abortNow = false;

    private Thread currentThread;

    protected final static boolean DEBUG = false;

    private String fSchemaLocation = null;
    private DOMStringList fRecognizedParameters;

    private boolean fNullFilterInUse = false;
    private AbortHandler abortHandler = null;

    //
    // Constructors
    //

    
Constructs a DOM Builder using the standard parser configuration.
/**
     * Constructs a DOM Builder using the standard parser configuration.
     */
    public DOMParserImpl (String configuration, String schemaType) {
        this (
        (XMLParserConfiguration) ObjectFactory.createObject (
        "org.apache.xerces.xni.parser.XMLParserConfiguration",
        configuration));
        if (schemaType != null) {
            if (schemaType.equals (Constants.NS_DTD)) {
                //Schema validation is false by default and hence there is no
                //need to set it to false here.  Also, schema validation is  
                //not a recognized feature for DTDConfiguration's and so 
                //setting this feature here would result in a Configuration 
                //Exception.            
                fConfiguration.setProperty (
                Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_LANGUAGE,
                Constants.NS_DTD);
                fSchemaType = Constants.NS_DTD;
            }
            else if (schemaType.equals (Constants.NS_XMLSCHEMA)) {
                // XML Schem validation
                fConfiguration.setProperty (
                Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_LANGUAGE,
                Constants.NS_XMLSCHEMA);
            }
        }

    }

    
Constructs a DOM Builder using the specified parser configuration.
/**
     * Constructs a DOM Builder using the specified parser configuration.
     */
    public DOMParserImpl (XMLParserConfiguration config) {
        super (config);

        // add recognized features
        final String[] domRecognizedFeatures = {
            Constants.DOM_CANONICAL_FORM,
            Constants.DOM_CDATA_SECTIONS,
            Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING,
            Constants.DOM_INFOSET,
            Constants.DOM_NAMESPACE_DECLARATIONS,
            Constants.DOM_SPLIT_CDATA,
            Constants.DOM_SUPPORTED_MEDIATYPES_ONLY,
            Constants.DOM_CERTIFIED,
            Constants.DOM_WELLFORMED,
            Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS,
        };

        fConfiguration.addRecognizedFeatures (domRecognizedFeatures);

        // turn off deferred DOM
        fConfiguration.setFeature (DEFER_NODE_EXPANSION, false);

        // Set values so that the value of the
        // infoset parameter is true (its default value).
        //
        // true: namespace-declarations, well-formed,
        // element-content-whitespace, comments, namespaces
        //
        // false: validate-if-schema, entities,
        // datatype-normalization, cdata-sections

        fConfiguration.setFeature(Constants.DOM_NAMESPACE_DECLARATIONS, true);
        fConfiguration.setFeature(Constants.DOM_WELLFORMED, true);
        fConfiguration.setFeature(INCLUDE_COMMENTS_FEATURE, true);
        fConfiguration.setFeature(INCLUDE_IGNORABLE_WHITESPACE, true);
        fConfiguration.setFeature(NAMESPACES, true);
		
        fConfiguration.setFeature(DYNAMIC_VALIDATION, false);
        fConfiguration.setFeature(CREATE_ENTITY_REF_NODES, false);
        fConfiguration.setFeature(CREATE_CDATA_NODES_FEATURE, false);

        // set other default values
        fConfiguration.setFeature (Constants.DOM_CANONICAL_FORM, false);
        fConfiguration.setFeature (Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING, true);
        fConfiguration.setFeature (Constants.DOM_SPLIT_CDATA, true);
        fConfiguration.setFeature (Constants.DOM_SUPPORTED_MEDIATYPES_ONLY, false);
        fConfiguration.setFeature (Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS, true);

        // REVISIT: by default Xerces assumes that input is certified.
        //          default is different from the one specified in the DOM spec
        fConfiguration.setFeature (Constants.DOM_CERTIFIED, true);

        // Xerces datatype-normalization feature is on by default
        // This is a recognized feature only for XML Schemas. If the
        // configuration doesn't support this feature, ignore it.
        try {
            fConfiguration.setFeature ( NORMALIZE_DATA, false );
        }
        catch (XMLConfigurationException exc) {}
    
    } // <init>(XMLParserConfiguration)

    
Constructs a DOM Builder using the specified symbol table.
/**
     * Constructs a DOM Builder using the specified symbol table.
     */
    public DOMParserImpl (SymbolTable symbolTable) {
        this (
        (XMLParserConfiguration) ObjectFactory.createObject (
        "org.apache.xerces.xni.parser.XMLParserConfiguration",
        "org.apache.xerces.parsers.XIncludeAwareParserConfiguration"));
        fConfiguration.setProperty (
        Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY,
        symbolTable);
    } // <init>(SymbolTable)


    
Constructs a DOM Builder using the specified symbol table and
grammar pool.
/**
     * Constructs a DOM Builder using the specified symbol table and
     * grammar pool.
     */
    public DOMParserImpl (SymbolTable symbolTable, XMLGrammarPool grammarPool) {
        this (
        (XMLParserConfiguration) ObjectFactory.createObject (
        "org.apache.xerces.xni.parser.XMLParserConfiguration",
        "org.apache.xerces.parsers.XIncludeAwareParserConfiguration"));
        fConfiguration.setProperty (
        Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY,
        symbolTable);
        fConfiguration.setProperty (
        Constants.XERCES_PROPERTY_PREFIX
        + Constants.XMLGRAMMAR_POOL_PROPERTY,
        grammarPool);
    }

    
Resets the parser state.
Throws:
SAXException – Thrown on initialization error./**
     * Resets the parser state.
     *
     * @throws SAXException Thrown on initialization error.
     */
    public void reset () {
        super.reset();
        
        // get state of namespace-declarations parameter.
        fNamespaceDeclarations = 
            fConfiguration.getFeature(Constants.DOM_NAMESPACE_DECLARATIONS);
                
        // DOM Filter
        if (fNullFilterInUse) {
            fDOMFilter = null;
            fNullFilterInUse = false;
        }
        if (fSkippedElemStack != null) {
            fSkippedElemStack.removeAllElements();
        }
        fRejectedElementDepth = 0;
        fFilterReject = false;
        fSchemaType = null;

    } // reset()

    //
    // DOMParser methods
    //

    public DOMConfiguration getDomConfig (){
        return this;
    }

    
When a filter is provided, the implementation will call out to the 
filter as it is constructing the DOM tree structure. The filter can 
choose to remove elements from the document being constructed, or to 
terminate the parsing early. 

 The filter is invoked after the operations requested by the 
DOMConfiguration parameters have been applied. For 
example, if "
validate" is set to true, the validation is done before invoking the 
filter. 
/**
     * When a filter is provided, the implementation will call out to the 
     * filter as it is constructing the DOM tree structure. The filter can 
     * choose to remove elements from the document being constructed, or to 
     * terminate the parsing early. 
     * <br> The filter is invoked after the operations requested by the 
     * <code>DOMConfiguration</code> parameters have been applied. For 
     * example, if "<a href='http://www.w3.org/TR/DOM-Level-3-Core/core.html#parameter-validate'>
     * validate</a>" is set to <code>true</code>, the validation is done before invoking the 
     * filter. 
     */
    public LSParserFilter getFilter () {
        return !fNullFilterInUse ? fDOMFilter : null;
    }

    
When a filter is provided, the implementation will call out to the 
filter as it is constructing the DOM tree structure. The filter can 
choose to remove elements from the document being constructed, or to 
terminate the parsing early. 

 The filter is invoked after the operations requested by the 
DOMConfiguration parameters have been applied. For 
example, if "
validate" is set to true, the validation is done before invoking the 
filter. 
/**
     * When a filter is provided, the implementation will call out to the 
     * filter as it is constructing the DOM tree structure. The filter can 
     * choose to remove elements from the document being constructed, or to 
     * terminate the parsing early. 
     * <br> The filter is invoked after the operations requested by the 
     * <code>DOMConfiguration</code> parameters have been applied. For 
     * example, if "<a href='http://www.w3.org/TR/DOM-Level-3-Core/core.html#parameter-validate'>
     * validate</a>" is set to <code>true</code>, the validation is done before invoking the 
     * filter. 
     */
    public void setFilter (LSParserFilter filter) {
        if (fBusy && filter == null && fDOMFilter != null) {
            fNullFilterInUse = true;
            fDOMFilter = NullLSParserFilter.INSTANCE;
        }
        else {
            fDOMFilter = filter;
        }
        if (fSkippedElemStack == null) {
            fSkippedElemStack = new Stack();
        }
    }

    
Set parameters and properties
/**
     * Set parameters and properties
     */
    public void setParameter (String name, Object value) throws DOMException {
        // set features
    	
        if (value instanceof Boolean) {
            boolean state = ((Boolean)value).booleanValue();
            try {
                if (name.equalsIgnoreCase (Constants.DOM_COMMENTS)) {
                    fConfiguration.setFeature (INCLUDE_COMMENTS_FEATURE, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_DATATYPE_NORMALIZATION)) {
                    fConfiguration.setFeature (NORMALIZE_DATA, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_ENTITIES)) {
                    fConfiguration.setFeature (CREATE_ENTITY_REF_NODES, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_DISALLOW_DOCTYPE)) {
                    fConfiguration.setFeature (DISALLOW_DOCTYPE_DECL_FEATURE, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_SUPPORTED_MEDIATYPES_ONLY)
                || name.equalsIgnoreCase(Constants.DOM_NORMALIZE_CHARACTERS)
                || name.equalsIgnoreCase (Constants.DOM_CHECK_CHAR_NORMALIZATION)
                || name.equalsIgnoreCase (Constants.DOM_CANONICAL_FORM)) {
                    if (state) { // true is not supported
                        throw newFeatureNotSupportedError(name);
                    }
                    // setting those features to false is no-op
                }
                else if (name.equalsIgnoreCase (Constants.DOM_NAMESPACES)) {
                    fConfiguration.setFeature (NAMESPACES, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_INFOSET)) {
                    // Setting false has no effect.
                    if (state) {
                        // true: namespaces, namespace-declarations, 
                        // comments, element-content-whitespace
                        fConfiguration.setFeature(NAMESPACES, true);
                        fConfiguration.setFeature(Constants.DOM_NAMESPACE_DECLARATIONS, true);
                        fConfiguration.setFeature(INCLUDE_COMMENTS_FEATURE, true);
                        fConfiguration.setFeature(INCLUDE_IGNORABLE_WHITESPACE, true);

                        // false: validate-if-schema, entities,
                        // datatype-normalization, cdata-sections
                        fConfiguration.setFeature(DYNAMIC_VALIDATION, false);
                        fConfiguration.setFeature(CREATE_ENTITY_REF_NODES, false);
                        fConfiguration.setFeature(NORMALIZE_DATA, false);
                        fConfiguration.setFeature(CREATE_CDATA_NODES_FEATURE, false);
                    }
                }
                else if (name.equalsIgnoreCase(Constants.DOM_CDATA_SECTIONS)) {
                    fConfiguration.setFeature(CREATE_CDATA_NODES_FEATURE, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_NAMESPACE_DECLARATIONS)) {
                    fConfiguration.setFeature(Constants.DOM_NAMESPACE_DECLARATIONS, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_WELLFORMED)
                || name.equalsIgnoreCase (Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS)) {
                    if (!state) { // false is not supported
                        throw newFeatureNotSupportedError(name);
                    }
                    // setting these features to true is no-op
                    // REVISIT: implement "namespace-declaration" feature
                }
                else if (name.equalsIgnoreCase (Constants.DOM_VALIDATE)) {
                    fConfiguration.setFeature (VALIDATION_FEATURE, state);
                    if (fSchemaType != Constants.NS_DTD) {
                        fConfiguration.setFeature (XMLSCHEMA, state);
                        fConfiguration.setFeature (XMLSCHEMA_FULL_CHECKING, state);
                    }
                    if (state){
                        fConfiguration.setFeature (DYNAMIC_VALIDATION, false);
                    }
                }
                else if (name.equalsIgnoreCase (Constants.DOM_VALIDATE_IF_SCHEMA)) {
                    fConfiguration.setFeature (DYNAMIC_VALIDATION, state);
                    // Note: validation and dynamic validation are mutually exclusive
                    if (state){
                        fConfiguration.setFeature (VALIDATION_FEATURE, false);
                    }
                }
                else if (name.equalsIgnoreCase (Constants.DOM_ELEMENT_CONTENT_WHITESPACE)) {
                    fConfiguration.setFeature (INCLUDE_IGNORABLE_WHITESPACE, state);
                }
                else if (name.equalsIgnoreCase (Constants.DOM_PSVI)){
                    //XSModel - turn on PSVI augmentation
                    fConfiguration.setFeature (PSVI_AUGMENT, true);
                    fConfiguration.setProperty (DOCUMENT_CLASS_NAME,
                    "org.apache.xerces.dom.PSVIDocumentImpl");
                }
                else {
                    // Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING feature,
                    // Constants.DOM_SPLIT_CDATA feature,
                    // or any Xerces feature
                    String normalizedName;
                    // The honour-all-schemaLocations feature is 
                    // mixed case so requires special treatment.
                    if (name.equalsIgnoreCase(HONOUR_ALL_SCHEMALOCATIONS)) {
                        normalizedName = HONOUR_ALL_SCHEMALOCATIONS;
                    }
                    else if (name.equals(NAMESPACE_GROWTH)) {
                        normalizedName = NAMESPACE_GROWTH;
                    }
                    else if (name.equals(TOLERATE_DUPLICATES)) {
                        normalizedName = TOLERATE_DUPLICATES;
                    }
                    else {
                        normalizedName = name.toLowerCase(Locale.ENGLISH);
                    }
                    fConfiguration.setFeature(normalizedName, state);
                }

            }
            catch (XMLConfigurationException e) {
                throw newFeatureNotFoundError(name);
            }
        }
        else { // set properties
            if (name.equalsIgnoreCase (Constants.DOM_ERROR_HANDLER)) {
                if (value instanceof DOMErrorHandler || value == null) {
                    try {
                        fErrorHandler = new DOMErrorHandlerWrapper ((DOMErrorHandler) value);
                        fConfiguration.setProperty (ERROR_HANDLER, fErrorHandler);
                    }
                    catch (XMLConfigurationException e) {}
                }
                else {
                    throw newTypeMismatchError(name);
                }

            }
            else if (name.equalsIgnoreCase (Constants.DOM_RESOURCE_RESOLVER)) {
                if (value instanceof LSResourceResolver || value == null) {
                    try {
                        fConfiguration.setProperty (ENTITY_RESOLVER, new DOMEntityResolverWrapper ((LSResourceResolver) value));
                    }
                    catch (XMLConfigurationException e) {}
                }
                else {
                    throw newTypeMismatchError(name);
                }

            }
            else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_LOCATION)) {
                if (value instanceof String || value == null) {
                    try {
                        if (value == null) {
                            fSchemaLocation = null;
                            fConfiguration.setProperty (
                                Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_SOURCE,
                                null);
                        }
                        else {
                            fSchemaLocation = (String)value;
                            // map DOM schema-location to JAXP schemaSource property
                            // tokenize location string
                            StringTokenizer t = new StringTokenizer (fSchemaLocation, " \n\t\r");
                            if (t.hasMoreTokens()) {
                                ArrayList locations = new ArrayList();
                                locations.add (t.nextToken());
                                while (t.hasMoreTokens()) {
                                    locations.add (t.nextToken());
                                }
                                fConfiguration.setProperty (
                                Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_SOURCE,
                                locations.toArray ());
                            }
                            else {
                                fConfiguration.setProperty (
                                Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_SOURCE,
                                value);
                            }
                        }
                    }
                    catch (XMLConfigurationException e) {}
                }
                else {
                    throw newTypeMismatchError(name);
                }

            }
            else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_TYPE)) {
                if (value instanceof String || value == null) {
                    try {
                        if (value == null) {
                            // turn off schema features
                            fConfiguration.setFeature (XMLSCHEMA, false);
                            fConfiguration.setFeature (XMLSCHEMA_FULL_CHECKING, false);
                            // map to JAXP schemaLanguage
                            fConfiguration.setProperty ( Constants.JAXP_PROPERTY_PREFIX
                            + Constants.SCHEMA_LANGUAGE,
                            null);
                            fSchemaType = null;
                        }
                        else if (value.equals (Constants.NS_XMLSCHEMA)) {
                            // turn on schema features
                            fConfiguration.setFeature (XMLSCHEMA, true);
                            fConfiguration.setFeature (XMLSCHEMA_FULL_CHECKING, true);
                            // map to JAXP schemaLanguage
                            fConfiguration.setProperty ( Constants.JAXP_PROPERTY_PREFIX
                            + Constants.SCHEMA_LANGUAGE,
                            Constants.NS_XMLSCHEMA);
                            fSchemaType = Constants.NS_XMLSCHEMA;
                        }
                        else if (value.equals (Constants.NS_DTD)) {
                            // turn off schema features
                            fConfiguration.setFeature (XMLSCHEMA, false);
                            fConfiguration.setFeature (XMLSCHEMA_FULL_CHECKING, false);
                            // map to JAXP schemaLanguage
                            fConfiguration.setProperty ( Constants.JAXP_PROPERTY_PREFIX
                            + Constants.SCHEMA_LANGUAGE,
                            Constants.NS_DTD);
                            fSchemaType = Constants.NS_DTD;
                        }
                    }
                    catch (XMLConfigurationException e) {}
                }
                else {
                    throw newTypeMismatchError(name);
                }

            }
            else if (name.equalsIgnoreCase (DOCUMENT_CLASS_NAME)) {
                fConfiguration.setProperty (DOCUMENT_CLASS_NAME, value);
            }
            else {
                // Try to set the property.
                String normalizedName = name.toLowerCase(Locale.ENGLISH);
                try {
                    fConfiguration.setProperty(normalizedName, value);
                    return;
                }
                catch (XMLConfigurationException e) {}
                
                // If this is a boolean parameter a type mismatch should be thrown.
                try {
                    // The honour-all-schemaLocations feature is 
                    // mixed case so requires special treatment.
                    if (name.equalsIgnoreCase(HONOUR_ALL_SCHEMALOCATIONS)) {
                        normalizedName = HONOUR_ALL_SCHEMALOCATIONS;
                    }
                    else if (name.equals(NAMESPACE_GROWTH)) {
                        normalizedName = NAMESPACE_GROWTH;
                    }
                    else if (name.equals(TOLERATE_DUPLICATES)) {
                        normalizedName = TOLERATE_DUPLICATES;
                    }
                    fConfiguration.getFeature(normalizedName);
                    throw newTypeMismatchError(name);
                    
                }
                catch (XMLConfigurationException e) {}
                
                // Parameter is not recognized
                throw newFeatureNotFoundError(name);
            }
        }
    }

    
Look up the value of a feature or a property.
/**
     * Look up the value of a feature or a property.
     */
    public Object getParameter (String name) throws DOMException {
        if (name.equalsIgnoreCase (Constants.DOM_COMMENTS)) {
            return (fConfiguration.getFeature (INCLUDE_COMMENTS_FEATURE))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_DATATYPE_NORMALIZATION)) {
            return (fConfiguration.getFeature (NORMALIZE_DATA))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_ENTITIES)) {
            return (fConfiguration.getFeature (CREATE_ENTITY_REF_NODES))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_NAMESPACES)) {
            return (fConfiguration.getFeature (NAMESPACES))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_VALIDATE)) {
            return (fConfiguration.getFeature (VALIDATION_FEATURE))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_VALIDATE_IF_SCHEMA)) {
            return (fConfiguration.getFeature (DYNAMIC_VALIDATION))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_ELEMENT_CONTENT_WHITESPACE)) {
            return (fConfiguration.getFeature (INCLUDE_IGNORABLE_WHITESPACE))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_DISALLOW_DOCTYPE)) {
            return (fConfiguration.getFeature (DISALLOW_DOCTYPE_DECL_FEATURE))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_INFOSET)) {
            // REVISIT: This is somewhat expensive to compute
            // but it's possible that the user has a reference
            // to the configuration and is changing the values
            // of these features directly on it.
            boolean infoset = fConfiguration.getFeature(NAMESPACES) &&
                fConfiguration.getFeature(Constants.DOM_NAMESPACE_DECLARATIONS) &&
                fConfiguration.getFeature(INCLUDE_COMMENTS_FEATURE) &&
                fConfiguration.getFeature(INCLUDE_IGNORABLE_WHITESPACE) &&
                !fConfiguration.getFeature(DYNAMIC_VALIDATION) &&
                !fConfiguration.getFeature(CREATE_ENTITY_REF_NODES) &&
                !fConfiguration.getFeature(NORMALIZE_DATA) &&
                !fConfiguration.getFeature(CREATE_CDATA_NODES_FEATURE);
            return (infoset) ? Boolean.TRUE : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase(Constants.DOM_CDATA_SECTIONS)) {
            return (fConfiguration.getFeature(CREATE_CDATA_NODES_FEATURE))
                ? Boolean.TRUE : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase(Constants.DOM_CHECK_CHAR_NORMALIZATION ) ||
                 name.equalsIgnoreCase(Constants.DOM_NORMALIZE_CHARACTERS)) {
            return Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase(Constants.DOM_NAMESPACE_DECLARATIONS)
        || name.equalsIgnoreCase (Constants.DOM_WELLFORMED)
        || name.equalsIgnoreCase (Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS)
        || name.equalsIgnoreCase (Constants.DOM_CANONICAL_FORM)
        || name.equalsIgnoreCase (Constants.DOM_SUPPORTED_MEDIATYPES_ONLY)
        || name.equalsIgnoreCase (Constants.DOM_SPLIT_CDATA)
        || name.equalsIgnoreCase (Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING)) {
            return (fConfiguration.getFeature (name.toLowerCase(Locale.ENGLISH)))
            ? Boolean.TRUE
            : Boolean.FALSE;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_ERROR_HANDLER)) {
            if (fErrorHandler != null) {
                return fErrorHandler.getErrorHandler ();
            }
            return null;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_RESOURCE_RESOLVER)) {
            try {
                XMLEntityResolver entityResolver =
                (XMLEntityResolver) fConfiguration.getProperty (ENTITY_RESOLVER);
                if (entityResolver != null
                        && entityResolver instanceof DOMEntityResolverWrapper) {
                    return ((DOMEntityResolverWrapper) entityResolver).getEntityResolver();
                }
            }
            catch (XMLConfigurationException e) {}
            return null;
        }
        else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_TYPE)) {
            return fConfiguration.getProperty (
            Constants.JAXP_PROPERTY_PREFIX + Constants.SCHEMA_LANGUAGE);
        }
        else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_LOCATION)) {
            return fSchemaLocation;
        }
        else if (name.equalsIgnoreCase (SYMBOL_TABLE)) {
            return fConfiguration.getProperty (SYMBOL_TABLE);
        }
        else if (name.equalsIgnoreCase (DOCUMENT_CLASS_NAME)) {
            return fConfiguration.getProperty (DOCUMENT_CLASS_NAME);
        }
        else {
            // This could be a recognized feature or property.
            String normalizedName;
            
            // The honour-all-schemaLocations feature is 
            // mixed case so requires special treatment.
            if (name.equalsIgnoreCase(HONOUR_ALL_SCHEMALOCATIONS)) {
                normalizedName = HONOUR_ALL_SCHEMALOCATIONS;
            }
            else if (name.equals(NAMESPACE_GROWTH)) {
                normalizedName = NAMESPACE_GROWTH;
            }
            else if (name.equals(TOLERATE_DUPLICATES)) {
                normalizedName = TOLERATE_DUPLICATES;
            }
            else {
                normalizedName = name.toLowerCase(Locale.ENGLISH);
            }
            try {
                return fConfiguration.getFeature(normalizedName) 
                    ? Boolean.TRUE : Boolean.FALSE;
            }
            catch (XMLConfigurationException e) {}
            
            // This isn't a feature; perhaps it's a property
            try {
                return fConfiguration.getProperty(normalizedName);
            }
            catch (XMLConfigurationException e) {}
            
            throw newFeatureNotFoundError(name);
        }
    }

    public boolean canSetParameter (String name, Object value) {
        if (value == null) {
            return true;
        }
        
        if (value instanceof Boolean) {
            boolean state = ((Boolean)value).booleanValue();
            if ( name.equalsIgnoreCase (Constants.DOM_SUPPORTED_MEDIATYPES_ONLY)
            || name.equalsIgnoreCase(Constants.DOM_NORMALIZE_CHARACTERS)
            || name.equalsIgnoreCase(Constants.DOM_CHECK_CHAR_NORMALIZATION )
            || name.equalsIgnoreCase (Constants.DOM_CANONICAL_FORM) ) {
                // true is not supported
                return (state) ? false : true;
            }
            else if (name.equalsIgnoreCase (Constants.DOM_WELLFORMED)
            || name.equalsIgnoreCase (Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS)) {
                // false is not supported
                return (state) ? true : false;
            }
            else if (name.equalsIgnoreCase (Constants.DOM_CDATA_SECTIONS)
            || name.equalsIgnoreCase (Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING)
            || name.equalsIgnoreCase (Constants.DOM_COMMENTS)
            || name.equalsIgnoreCase (Constants.DOM_DATATYPE_NORMALIZATION)
            || name.equalsIgnoreCase (Constants.DOM_DISALLOW_DOCTYPE)
            || name.equalsIgnoreCase (Constants.DOM_ENTITIES)
            || name.equalsIgnoreCase (Constants.DOM_INFOSET)
            || name.equalsIgnoreCase (Constants.DOM_NAMESPACES)
            || name.equalsIgnoreCase (Constants.DOM_NAMESPACE_DECLARATIONS)
            || name.equalsIgnoreCase (Constants.DOM_VALIDATE)
            || name.equalsIgnoreCase (Constants.DOM_VALIDATE_IF_SCHEMA)
            || name.equalsIgnoreCase (Constants.DOM_ELEMENT_CONTENT_WHITESPACE)
            || name.equalsIgnoreCase (Constants.DOM_XMLDECL)) {
                return true;
            }

            // Recognize Xerces features.
            try {
                String normalizedName;
                // The honour-all-schemaLocations feature is 
                // mixed case so requires special treatment.
                if (name.equalsIgnoreCase(HONOUR_ALL_SCHEMALOCATIONS)) {
                    normalizedName = HONOUR_ALL_SCHEMALOCATIONS;
                }
                else if (name.equalsIgnoreCase(NAMESPACE_GROWTH)) {
                    normalizedName = NAMESPACE_GROWTH;
                }
                else if (name.equalsIgnoreCase(TOLERATE_DUPLICATES)) {
                    normalizedName = TOLERATE_DUPLICATES;
                }
                else {
                    normalizedName = name.toLowerCase(Locale.ENGLISH);
                }
                fConfiguration.getFeature(normalizedName);
                return true;
            }
            catch (XMLConfigurationException e) {
                return false;
            }
        }
        else { // check properties
            if (name.equalsIgnoreCase (Constants.DOM_ERROR_HANDLER)) {
                if (value instanceof DOMErrorHandler || value == null) {
                    return true;
                }
                return false;
            }
            else if (name.equalsIgnoreCase (Constants.DOM_RESOURCE_RESOLVER)) {
                if (value instanceof LSResourceResolver || value == null) {
                    return true;
                }
                return false;
            }
            else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_TYPE)) {
                if ((value instanceof String
                && (value.equals (Constants.NS_XMLSCHEMA)
                || value.equals (Constants.NS_DTD))) || value == null) {
                    return true;
                }
                return false;
            }
            else if (name.equalsIgnoreCase (Constants.DOM_SCHEMA_LOCATION)) {
                if (value instanceof String || value == null)
                    return true;
                return false;
            }
            else if (name.equalsIgnoreCase (DOCUMENT_CLASS_NAME)) {
                return true;
            }
            
            // Recognize Xerces properties.
            try {
                fConfiguration.getProperty(name.toLowerCase(Locale.ENGLISH));
                return true;
            }
            catch (XMLConfigurationException e) {
                return false;
            }
        }
    }

    
 DOM Level 3 CR - Experimental.
 The list of the parameters supported by this
DOMConfiguration object and for which at least one value
can be set by the application. Note that this list can also contain
parameter names defined outside this specification.
/**
     *  DOM Level 3 CR - Experimental.
     *
     *  The list of the parameters supported by this
     * <code>DOMConfiguration</code> object and for which at least one value
     * can be set by the application. Note that this list can also contain
     * parameter names defined outside this specification.
     */
    public DOMStringList getParameterNames () {
        if (fRecognizedParameters == null){
            ArrayList parameters = new ArrayList();
            
            // REVISIT: add Xerces recognized properties/features
            parameters.add(Constants.DOM_NAMESPACES);
            parameters.add(Constants.DOM_CDATA_SECTIONS);
            parameters.add(Constants.DOM_CANONICAL_FORM);
            parameters.add(Constants.DOM_NAMESPACE_DECLARATIONS);
            parameters.add(Constants.DOM_SPLIT_CDATA);
            
            parameters.add(Constants.DOM_ENTITIES);
            parameters.add(Constants.DOM_VALIDATE_IF_SCHEMA);
            parameters.add(Constants.DOM_VALIDATE);
            parameters.add(Constants.DOM_DATATYPE_NORMALIZATION);
            
            parameters.add(Constants.DOM_CHARSET_OVERRIDES_XML_ENCODING);
            parameters.add(Constants.DOM_CHECK_CHAR_NORMALIZATION);
            parameters.add(Constants.DOM_SUPPORTED_MEDIATYPES_ONLY);
            parameters.add(Constants.DOM_IGNORE_UNKNOWN_CHARACTER_DENORMALIZATIONS);
            
            parameters.add(Constants.DOM_NORMALIZE_CHARACTERS);
            parameters.add(Constants.DOM_WELLFORMED);
            parameters.add(Constants.DOM_INFOSET);
            parameters.add(Constants.DOM_DISALLOW_DOCTYPE);
            parameters.add(Constants.DOM_ELEMENT_CONTENT_WHITESPACE);
            parameters.add(Constants.DOM_COMMENTS);
            
            parameters.add(Constants.DOM_ERROR_HANDLER);
            parameters.add(Constants.DOM_RESOURCE_RESOLVER);
            parameters.add(Constants.DOM_SCHEMA_LOCATION);
            parameters.add(Constants.DOM_SCHEMA_TYPE);
            
            fRecognizedParameters = new DOMStringListImpl(parameters);
            
        }
        
        return fRecognizedParameters;
    }

    
Parse an XML document from a location identified by an URI reference.
If the URI contains a fragment identifier (see section 4.1 in ), the
behavior is not defined by this specification.
/**
     * Parse an XML document from a location identified by an URI reference.
     * If the URI contains a fragment identifier (see section 4.1 in ), the
     * behavior is not defined by this specification.
     *
     */
    public Document parseURI (String uri) throws LSException {

        //If DOMParser insstance is already busy parsing another document when this
        // method is called, then raise INVALID_STATE_ERR according to DOM L3 LS spec
        if ( fBusy ) {
            throw newInvalidStateError();
        }

        XMLInputSource source = new XMLInputSource (null, uri, null);
        try {
            currentThread = Thread.currentThread();
			fBusy = true;
            parse (source);
            fBusy = false;
            if (abortNow && currentThread.isInterrupted()) {
                //reset interrupt state 
                abortNow = false;
                Thread.interrupted();
            }
        } catch (Exception e){
            fBusy = false;
            if (abortNow && currentThread.isInterrupted()) {
                Thread.interrupted();
            }
            if (abortNow) {
                abortNow = false;
                restoreHandlers();
                return null;
            }
            // Consume this exception if the user
            // issued an interrupt or an abort.
            if (e != Abort.INSTANCE) {
                if (!(e instanceof XMLParseException) && fErrorHandler != null) {
                    DOMErrorImpl error = new DOMErrorImpl ();
                    error.fException = e;
                    error.fMessage = e.getMessage ();
                    error.fSeverity = DOMError.SEVERITY_FATAL_ERROR;
                    fErrorHandler.getErrorHandler ().handleError (error);
                }
                if (DEBUG) {
                    e.printStackTrace ();
                }
                throw (LSException) DOMUtil.createLSException(LSException.PARSE_ERR, e).fillInStackTrace();
            }
        }
        Document doc = getDocument();
        dropDocumentReferences();
        return doc;
    }

    
Parse an XML document from a resource identified by an
LSInput.
/**
     * Parse an XML document from a resource identified by an
     * <code>LSInput</code>.
     *
     */
    public Document parse (LSInput is) throws LSException {

        // need to wrap the LSInput with an XMLInputSource
        XMLInputSource xmlInputSource = dom2xmlInputSource (is);
        if ( fBusy ) {
            throw newInvalidStateError();
        }

        try {
            currentThread = Thread.currentThread();
			fBusy = true;
            parse (xmlInputSource);
            fBusy = false;   
            if (abortNow && currentThread.isInterrupted()) {
                //reset interrupt state 
                abortNow = false;
                Thread.interrupted();
            }
        } catch (Exception e) {
            fBusy = false;
            if (abortNow && currentThread.isInterrupted()) {
                Thread.interrupted();
            }
            if (abortNow) {
                abortNow = false;
                restoreHandlers();
                return null;
            }
            // Consume this exception if the user
            // issued an interrupt or an abort.
            if (e != Abort.INSTANCE) {
                if (!(e instanceof XMLParseException) && fErrorHandler != null) {
                   DOMErrorImpl error = new DOMErrorImpl ();
                   error.fException = e;
                   error.fMessage = e.getMessage ();
                   error.fSeverity = DOMError.SEVERITY_FATAL_ERROR;
                   fErrorHandler.getErrorHandler().handleError (error);
                }
                if (DEBUG) {
                   e.printStackTrace ();
                }
                throw (LSException) DOMUtil.createLSException(LSException.PARSE_ERR, e).fillInStackTrace();
            }
        }
        Document doc = getDocument();
        dropDocumentReferences();
        return doc;
    }


    private void restoreHandlers() {
        fConfiguration.setDocumentHandler(this);
        fConfiguration.setDTDHandler(this);
        fConfiguration.setDTDContentModelHandler(this);
    }

    
 Parse an XML document or fragment from a resource identified by an
LSInput and insert the content into an existing
document at the position epcified with the contextNode
and action arguments. When parsing the input stream the
context node is used for resolving unbound namespace prefixes.
Params:
is –  The LSInput from which the source
  document is to be read.
cnode –  The Node that is used as the context for
  the data that is being parsed.
action – This parameter describes which action should be taken
  between the new set of node being inserted and the existing
  children of the context node. The set of possible actions is
  defined above.
Throws:
DOMException – 
  HIERARCHY_REQUEST_ERR: Thrown if this action results in an invalid
  hierarchy (i.e. a Document with more than one document element)./**
     *  Parse an XML document or fragment from a resource identified by an
     * <code>LSInput</code> and insert the content into an existing
     * document at the position epcified with the <code>contextNode</code>
     * and <code>action</code> arguments. When parsing the input stream the
     * context node is used for resolving unbound namespace prefixes.
     *
     * @param is  The <code>LSInput</code> from which the source
     *   document is to be read.
     * @param cnode  The <code>Node</code> that is used as the context for
     *   the data that is being parsed.
     * @param action This parameter describes which action should be taken
     *   between the new set of node being inserted and the existing
     *   children of the context node. The set of possible actions is
     *   defined above.
     * @exception DOMException
     *   HIERARCHY_REQUEST_ERR: Thrown if this action results in an invalid
     *   hierarchy (i.e. a Document with more than one document element).
     */
    public Node parseWithContext (LSInput is, Node cnode,
    short action) throws DOMException, LSException {
        // REVISIT: need to implement.
        throw new DOMException (DOMException.NOT_SUPPORTED_ERR, "Not supported");
    }


    
NON-DOM: convert LSInput to XNIInputSource
Params:
is – 
Returns:
/**
     * NON-DOM: convert LSInput to XNIInputSource
     *
     * @param is
     * @return

     */
    XMLInputSource dom2xmlInputSource (LSInput is) {
        // need to wrap the LSInput with an XMLInputSource
        XMLInputSource xis = null;
        // check whether there is a Reader
        // according to DOM, we need to treat such reader as "UTF-16".
        if (is.getCharacterStream () != null) {
            xis = new XMLInputSource (is.getPublicId (), is.getSystemId (),
            is.getBaseURI (), is.getCharacterStream (),
            "UTF-16");
        }
        // check whether there is an InputStream
        else if (is.getByteStream () != null) {
            xis = new XMLInputSource (is.getPublicId (), is.getSystemId (),
            is.getBaseURI (), is.getByteStream (),
            is.getEncoding ());
        }
        // if there is a string data, use a StringReader
        // according to DOM, we need to treat such data as "UTF-16".
        else if (is.getStringData () != null && is.getStringData().length() > 0) {
            xis = new XMLInputSource (is.getPublicId (), is.getSystemId (),
            is.getBaseURI (), new StringReader (is.getStringData ()),
            "UTF-16");
        }
        // otherwise, just use the public/system/base Ids
        else if ((is.getSystemId() != null && is.getSystemId().length() > 0) || 
            (is.getPublicId() != null && is.getPublicId().length() > 0)) {
            xis = new XMLInputSource (is.getPublicId (), is.getSystemId (),
            is.getBaseURI ());
        }
        else { 
            // all inputs are null
            if (fErrorHandler != null) {
                DOMErrorImpl error = new DOMErrorImpl();
                error.fType = "no-input-specified";
                error.fMessage = "no-input-specified";
                error.fSeverity = DOMError.SEVERITY_FATAL_ERROR;
                fErrorHandler.getErrorHandler().handleError(error);
            }
            throw new LSException(LSException.PARSE_ERR, "no-input-specified");
        }
        return xis;
    }

    
See Also:
getAsync.getAsync()/**
     * @see org.w3c.dom.ls.LSParser#getAsync()
     */
    public boolean getAsync () {
        return false;
    }

    
See Also:
getBusy.getBusy()/**
     * @see org.w3c.dom.ls.LSParser#getBusy()
     */
    public boolean getBusy () {
        return fBusy;
    }

    
See Also:
abort.abort()/**
     * @see org.w3c.dom.ls.LSParser#abort()
     */
    public void abort () {
        // If parse operation is in progress then reset it
        if (fBusy) {
            fBusy = false;
            if (currentThread != null) {
                abortNow = true;
                if (abortHandler == null) {
                    abortHandler = new AbortHandler();
                }
                fConfiguration.setDocumentHandler(abortHandler);
                fConfiguration.setDTDHandler(abortHandler);
                fConfiguration.setDTDContentModelHandler(abortHandler);
                if (currentThread == Thread.currentThread()) {
                    throw Abort.INSTANCE;
                }
                currentThread.interrupt();
            }               
        }
        return; // If not busy then this is noop
    }

    
The start of an element. If the document specifies the start element
by using an empty tag, then the startElement method will immediately
be followed by the endElement method, with no intervening methods.
Overriding the parent to handle DOM_NAMESPACE_DECLARATIONS=false.
Params:
element –    The name of the element.
attributes – The element attributes.
augs –     Additional information that may include infoset augmentations
Throws:
XNIException – Thrown by handler to signal an error./**
     * The start of an element. If the document specifies the start element
     * by using an empty tag, then the startElement method will immediately
     * be followed by the endElement method, with no intervening methods.
     * Overriding the parent to handle DOM_NAMESPACE_DECLARATIONS=false.
     *
     * @param element    The name of the element.
     * @param attributes The element attributes.
     * @param augs     Additional information that may include infoset augmentations
     *
     * @throws XNIException Thrown by handler to signal an error.
     */
    public void startElement (QName element, XMLAttributes attributes, Augmentations augs) {
        // namespace declarations parameter has no effect if namespaces is false.
        if (!fNamespaceDeclarations && fNamespaceAware) {
            int len = attributes.getLength();
            for (int i = len - 1; i >= 0; --i) {
                if (XMLSymbols.PREFIX_XMLNS == attributes.getPrefix(i) ||
                    XMLSymbols.PREFIX_XMLNS == attributes.getQName(i)) {
                    attributes.removeAttributeAt(i);
                }
            }
        }
        super.startElement(element, attributes, augs);
    }
    
    static final class NullLSParserFilter implements LSParserFilter {
        static final NullLSParserFilter INSTANCE = new NullLSParserFilter();
        private NullLSParserFilter() {}
        public short acceptNode(Node nodeArg) {
            return LSParserFilter.FILTER_ACCEPT;
        }
        public int getWhatToShow() {
            return NodeFilter.SHOW_ALL;
        }
        public short startElement(Element elementArg) {
            return LSParserFilter.FILTER_ACCEPT;
        }
    }
    
    private static final class AbortHandler implements XMLDocumentHandler, XMLDTDHandler, XMLDTDContentModelHandler {

        private XMLDocumentSource documentSource;
        private XMLDTDContentModelSource dtdContentSource;
        private XMLDTDSource dtdSource;

        public void startDocument(XMLLocator locator, String encoding, NamespaceContext namespaceContext, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void xmlDecl(String version, String encoding, String standalone, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void doctypeDecl(String rootElement, String publicId, String systemId, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void comment(XMLString text, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void processingInstruction(String target, XMLString data, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startElement(QName element, XMLAttributes attributes, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void emptyElement(QName element, XMLAttributes attributes, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startGeneralEntity(String name, XMLResourceIdentifier identifier, String encoding, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void textDecl(String version, String encoding, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endGeneralEntity(String name, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void characters(XMLString text, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void ignorableWhitespace(XMLString text, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endElement(QName element, Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startCDATA(Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endCDATA(Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endDocument(Augmentations augs) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void setDocumentSource(XMLDocumentSource source) {
            documentSource = source;
        }

        public XMLDocumentSource getDocumentSource() {
            return documentSource;
        }

        public void startDTD(XMLLocator locator, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startParameterEntity(String name, XMLResourceIdentifier identifier, String encoding, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endParameterEntity(String name, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startExternalSubset(XMLResourceIdentifier identifier, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endExternalSubset(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void elementDecl(String name, String contentModel, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startAttlist(String elementName, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void attributeDecl(String elementName, String attributeName, String type, String[] enumeration, String defaultType, XMLString defaultValue, XMLString nonNormalizedDefaultValue, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endAttlist(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void internalEntityDecl(String name, XMLString text, XMLString nonNormalizedText, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void externalEntityDecl(String name, XMLResourceIdentifier identifier, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void unparsedEntityDecl(String name, XMLResourceIdentifier identifier, String notation, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void notationDecl(String name, XMLResourceIdentifier identifier, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startConditional(short type, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void ignoredCharacters(XMLString text, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endConditional(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endDTD(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void setDTDSource(XMLDTDSource source) {
            dtdSource = source;
        }

        public XMLDTDSource getDTDSource() {
            return dtdSource;
        }

        public void startContentModel(String elementName, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void any(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void empty(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void startGroup(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void pcdata(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void element(String elementName, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void separator(short separator, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void occurrence(short occurrence, Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endGroup(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void endContentModel(Augmentations augmentations) throws XNIException {
            throw Abort.INSTANCE;
        }

        public void setDTDContentModelSource(XMLDTDContentModelSource source) {
            dtdContentSource = source;
        }

        public XMLDTDContentModelSource getDTDContentModelSource() {
            return dtdContentSource;
        }  
    }
    
    private static DOMException newInvalidStateError() {
        String msg = 
            DOMMessageFormatter.formatMessage (
                    DOMMessageFormatter.DOM_DOMAIN,
                    "INVALID_STATE_ERR", null);
        throw new DOMException ( DOMException.INVALID_STATE_ERR, msg);
    }
    
    private static DOMException newFeatureNotSupportedError(String name) {
        String msg =
            DOMMessageFormatter.formatMessage (
                    DOMMessageFormatter.DOM_DOMAIN,
                    "FEATURE_NOT_SUPPORTED",
                    new Object[] { name });
        return new DOMException (DOMException.NOT_SUPPORTED_ERR, msg);
    }
    
    private static DOMException newFeatureNotFoundError(String name) {
        String msg =
            DOMMessageFormatter.formatMessage (
                    DOMMessageFormatter.DOM_DOMAIN,
                    "FEATURE_NOT_FOUND",
                    new Object[] { name });
        return new DOMException (DOMException.NOT_FOUND_ERR, msg);
    }
    
    private static DOMException newTypeMismatchError(String name) {
        String msg =
            DOMMessageFormatter.formatMessage (
                    DOMMessageFormatter.DOM_DOMAIN,
                    "TYPE_MISMATCH_ERR",
                    new Object[] { name });
        return new DOMException (DOMException.TYPE_MISMATCH_ERR, msg);
    }
	
} // class DOMParserImpl