/*
 * 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;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.Stack;
import java.util.StringTokenizer;

import org.apache.xerces.impl.io.ASCIIReader;
import org.apache.xerces.impl.io.Latin1Reader;
import org.apache.xerces.impl.io.UCSReader;
import org.apache.xerces.impl.io.UTF16Reader;
import org.apache.xerces.impl.io.UTF8Reader;
import org.apache.xerces.impl.msg.XMLMessageFormatter;
import org.apache.xerces.impl.validation.ValidationManager;
import org.apache.xerces.util.AugmentationsImpl;
import org.apache.xerces.util.EncodingMap;
import org.apache.xerces.util.HTTPInputSource;
import org.apache.xerces.util.SecurityManager;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.URI;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.util.XMLEntityDescriptionImpl;
import org.apache.xerces.util.XMLResourceIdentifierImpl;
import org.apache.xerces.xni.Augmentations;
import org.apache.xerces.xni.XMLResourceIdentifier;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.parser.XMLComponent;
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.XMLInputSource;

The entity manager handles the registration of general and parameter
entities; resolves entities; and starts entities. The entity manager
is a central component in a standard parser configuration and this
class works directly with the entity scanner to manage the underlying
xni.

This component requires the following features and properties from the
component manager that uses it:

 
http://xml.org/sax/features/validation
 
http://xml.org/sax/features/external-general-entities
 
http://xml.org/sax/features/external-parameter-entities
 
http://apache.org/xml/features/allow-java-encodings
 
http://apache.org/xml/properties/internal/symbol-table
 
http://apache.org/xml/properties/internal/error-reporter
 
http://apache.org/xml/properties/internal/entity-resolver

Author:
Andy Clark, IBM, Arnaud  Le Hors, IBM
@xerces.internal
Version:
$Id: XMLEntityManager.java 1513559 2013-08-13 15:42:35Z mrglavas $/**
 * The entity manager handles the registration of general and parameter
 * entities; resolves entities; and starts entities. The entity manager
 * is a central component in a standard parser configuration and this
 * class works directly with the entity scanner to manage the underlying
 * xni.
 * <p>
 * This component requires the following features and properties from the
 * component manager that uses it:
 * <ul>
 *  <li>http://xml.org/sax/features/validation</li>
 *  <li>http://xml.org/sax/features/external-general-entities</li>
 *  <li>http://xml.org/sax/features/external-parameter-entities</li>
 *  <li>http://apache.org/xml/features/allow-java-encodings</li>
 *  <li>http://apache.org/xml/properties/internal/symbol-table</li>
 *  <li>http://apache.org/xml/properties/internal/error-reporter</li>
 *  <li>http://apache.org/xml/properties/internal/entity-resolver</li>
 * </ul>
 *
 * @xerces.internal

 * 
 * @author Andy Clark, IBM
 * @author Arnaud  Le Hors, IBM
 *
 * @version $Id: XMLEntityManager.java 1513559 2013-08-13 15:42:35Z mrglavas $
 */
public class XMLEntityManager
    implements XMLComponent, XMLEntityResolver {

    //
    // Constants
    //

    
Default buffer size (2048). /** Default buffer size (2048). */
    public static final int DEFAULT_BUFFER_SIZE = 2048; 

    
Default buffer size before we've finished with the XMLDecl:  /** Default buffer size before we've finished with the XMLDecl:  */
    public static final int DEFAULT_XMLDECL_BUFFER_SIZE = 64;

    
Default internal entity buffer size (512). /** Default internal entity buffer size (512). */
    public static final int DEFAULT_INTERNAL_BUFFER_SIZE = 512;

    // feature identifiers

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

    
Feature identifier: external general entities. /** Feature identifier: external general entities. */
    protected static final String EXTERNAL_GENERAL_ENTITIES =
        Constants.SAX_FEATURE_PREFIX + Constants.EXTERNAL_GENERAL_ENTITIES_FEATURE;

    
Feature identifier: external parameter entities. /** Feature identifier: external parameter entities. */
    protected static final String EXTERNAL_PARAMETER_ENTITIES =
        Constants.SAX_FEATURE_PREFIX + Constants.EXTERNAL_PARAMETER_ENTITIES_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: warn on duplicate EntityDef /** Feature identifier: warn on duplicate EntityDef */
    protected static final String WARN_ON_DUPLICATE_ENTITYDEF =
    Constants.XERCES_FEATURE_PREFIX +Constants.WARN_ON_DUPLICATE_ENTITYDEF_FEATURE;

    
Feature identifier: standard uri conformant /** Feature identifier: standard uri conformant */
    protected static final String STANDARD_URI_CONFORMANT =
    Constants.XERCES_FEATURE_PREFIX +Constants.STANDARD_URI_CONFORMANT_FEATURE;
    
	protected static final String PARSER_SETTINGS = 
		Constants.XERCES_FEATURE_PREFIX + Constants.PARSER_SETTINGS;	

    // property identifiers

    
Property identifier: symbol table. /** Property identifier: symbol table. */
    protected static final String SYMBOL_TABLE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SYMBOL_TABLE_PROPERTY;

    
Property identifier: error reporter. /** Property identifier: error reporter. */
    protected static final String ERROR_REPORTER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ERROR_REPORTER_PROPERTY;

    
Property identifier: entity resolver. /** Property identifier: entity resolver. */
    protected static final String ENTITY_RESOLVER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.ENTITY_RESOLVER_PROPERTY;

    // property identifier:  ValidationManager
    protected static final String VALIDATION_MANAGER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.VALIDATION_MANAGER_PROPERTY;

    
property identifier: buffer size. /** property identifier: buffer size. */
    protected static final String BUFFER_SIZE =
        Constants.XERCES_PROPERTY_PREFIX + Constants.BUFFER_SIZE_PROPERTY;

    
property identifier: security manager. /** property identifier: security manager. */
    protected static final String SECURITY_MANAGER =
        Constants.XERCES_PROPERTY_PREFIX + Constants.SECURITY_MANAGER_PROPERTY;

    // recognized features and properties

    
Recognized features. /** Recognized features. */
    private static final String[] RECOGNIZED_FEATURES = {
        VALIDATION,
        EXTERNAL_GENERAL_ENTITIES,
        EXTERNAL_PARAMETER_ENTITIES,
        ALLOW_JAVA_ENCODINGS,
        WARN_ON_DUPLICATE_ENTITYDEF,
        STANDARD_URI_CONFORMANT
    };

    
Feature defaults. /** Feature defaults. */
    private static final Boolean[] FEATURE_DEFAULTS = {
        null,
        Boolean.TRUE,
        Boolean.TRUE,
        Boolean.FALSE,
        Boolean.FALSE,
        Boolean.FALSE
    };

    
Recognized properties. /** Recognized properties. */
    private static final String[] RECOGNIZED_PROPERTIES = {
        SYMBOL_TABLE,
        ERROR_REPORTER,
        ENTITY_RESOLVER,
        VALIDATION_MANAGER,
        BUFFER_SIZE,
        SECURITY_MANAGER,
    };

    
Property defaults. /** Property defaults. */
    private static final Object[] PROPERTY_DEFAULTS = {
        null,
        null,
        null,
        null,
        new Integer(DEFAULT_BUFFER_SIZE),
        null,
    };

    private static final String XMLEntity = "[xml]".intern();
    private static final String DTDEntity = "[dtd]".intern();
    
    // debugging

    
Debug printing of buffer. This debugging flag works best when you
resize the DEFAULT_BUFFER_SIZE down to something reasonable like
64 characters.
/**
     * Debug printing of buffer. This debugging flag works best when you
     * resize the DEFAULT_BUFFER_SIZE down to something reasonable like
     * 64 characters.
     */
    private static final boolean DEBUG_BUFFER = false;

    
Debug some basic entities. /** Debug some basic entities. */
    private static final boolean DEBUG_ENTITIES = false;

    
Debug switching readers for encodings. /** Debug switching readers for encodings. */
    private static final boolean DEBUG_ENCODINGS = false;

    // should be diplayed trace resolving messages
    private static final boolean DEBUG_RESOLVER = false;

    //
    // Data
    //

    // features

    
Validation. This feature identifier is:
http://xml.org/sax/features/validation
/**
     * Validation. This feature identifier is:
     * http://xml.org/sax/features/validation
     */
    protected boolean fValidation;

    
External general entities. This feature identifier is:
http://xml.org/sax/features/external-general-entities
/**
     * External general entities. This feature identifier is:
     * http://xml.org/sax/features/external-general-entities
     */
    protected boolean fExternalGeneralEntities = true;

    
External parameter entities. This feature identifier is:
http://xml.org/sax/features/external-parameter-entities
/**
     * External parameter entities. This feature identifier is:
     * http://xml.org/sax/features/external-parameter-entities
     */
    protected boolean fExternalParameterEntities = true;

    
Allow Java encoding names. This feature identifier is:
http://apache.org/xml/features/allow-java-encodings
/**
     * Allow Java encoding names. This feature identifier is:
     * http://apache.org/xml/features/allow-java-encodings
     */
    protected boolean fAllowJavaEncodings;

    
warn on duplicate Entity declaration.
 http://apache.org/xml/features/warn-on-duplicate-entitydef
/** warn on duplicate Entity declaration.
     *  http://apache.org/xml/features/warn-on-duplicate-entitydef
     */
    protected boolean fWarnDuplicateEntityDef;

    
standard uri conformant (strict uri).
http://apache.org/xml/features/standard-uri-conformant
/**
     * standard uri conformant (strict uri).
     * http://apache.org/xml/features/standard-uri-conformant
     */
    protected boolean fStrictURI;

    // properties

    
Symbol table. This property identifier is:
http://apache.org/xml/properties/internal/symbol-table
/**
     * Symbol table. This property identifier is:
     * http://apache.org/xml/properties/internal/symbol-table
     */
    protected SymbolTable fSymbolTable;

    
Error reporter. This property identifier is:
http://apache.org/xml/properties/internal/error-reporter
/**
     * Error reporter. This property identifier is:
     * http://apache.org/xml/properties/internal/error-reporter
     */
    protected XMLErrorReporter fErrorReporter;

    
Entity resolver. This property identifier is:
http://apache.org/xml/properties/internal/entity-resolver
/**
     * Entity resolver. This property identifier is:
     * http://apache.org/xml/properties/internal/entity-resolver
     */
    protected XMLEntityResolver fEntityResolver;

    
Validation manager. This property identifier is:
http://apache.org/xml/properties/internal/validation-manager
/**
     * Validation manager. This property identifier is:
     * http://apache.org/xml/properties/internal/validation-manager
     */
    protected ValidationManager fValidationManager;

    // settings

    
Buffer size. We get this value from a property. The default size
is used if the input buffer size property is not specified.
REVISIT: do we need a property for internal entity buffer size?
/**
     * Buffer size. We get this value from a property. The default size
     * is used if the input buffer size property is not specified.
     * REVISIT: do we need a property for internal entity buffer size?
     */
    protected int fBufferSize = DEFAULT_BUFFER_SIZE;

    // stores defaults for entity expansion limit if it has
    // been set on the configuration.
    protected SecurityManager fSecurityManager = null;

    
True if the document entity is standalone. This should really
only be set by the document source (e.g. XMLDocumentScanner).
/**
     * True if the document entity is standalone. This should really
     * only be set by the document source (e.g. XMLDocumentScanner).
     */
    protected boolean fStandalone;
    
    
True if the current document contains parameter entity references.
/**
     * True if the current document contains parameter entity references.
     */
    protected boolean fHasPEReferences;

    // are the entities being parsed in the external subset?
    // NOTE:  this *is not* the same as whether they're external entities!
    protected boolean fInExternalSubset = false;

    // handlers

    
Entity handler. /** Entity handler. */
    protected XMLEntityHandler fEntityHandler;

    // scanner

    
Current entity scanner. /** Current entity scanner. */
    protected XMLEntityScanner fEntityScanner;

    
XML 1.0 entity scanner. /** XML 1.0 entity scanner. */
    protected XMLEntityScanner fXML10EntityScanner;

    
XML 1.1 entity scanner. /** XML 1.1 entity scanner. */
    protected XMLEntityScanner fXML11EntityScanner;

    // entity expansion limit (contains useful data if and only if
    // fSecurityManager is non-null)
    protected int fEntityExpansionLimit = 0;
    // entity currently being expanded:
    protected int fEntityExpansionCount = 0;

    // entities

    
Entities. /** Entities. */
    protected final Hashtable fEntities = new Hashtable();

    
Entity stack. /** Entity stack. */
    protected final Stack fEntityStack = new Stack();

    
Current entity. /** Current entity. */
    protected ScannedEntity fCurrentEntity;

    // shared context

    
Shared declared entities. /** Shared declared entities. */
    protected Hashtable fDeclaredEntities;

    // temp vars

    
Resource identifier. /** Resource identifier. */
    private final XMLResourceIdentifierImpl fResourceIdentifier = new XMLResourceIdentifierImpl();
    
    
Augmentations for entities. /** Augmentations for entities. */
    private final Augmentations fEntityAugs = new AugmentationsImpl();
    
    
Pool of byte buffers for single byte and variable width encodings, such as US-ASCII and UTF-8. /** Pool of byte buffers for single byte and variable width encodings, such as US-ASCII and UTF-8. */
    private final ByteBufferPool fSmallByteBufferPool = new ByteBufferPool(fBufferSize);
    
    
Pool of byte buffers for 2-byte encodings, such as UTF-16. /** Pool of byte buffers for 2-byte encodings, such as UTF-16. **/
    private final ByteBufferPool fLargeByteBufferPool = new ByteBufferPool(fBufferSize << 1);
    
    
Temporary storage for the current entity's byte buffer. /** Temporary storage for the current entity's byte buffer. */
    private byte[] fTempByteBuffer = null;
    
    
Pool of character buffers. /** Pool of character buffers. */
    private final CharacterBufferPool fCharacterBufferPool = new CharacterBufferPool(fBufferSize, DEFAULT_INTERNAL_BUFFER_SIZE);

    //
    // Constructors
    //

    
Default constructor. /** Default constructor. */
    public XMLEntityManager() {
        this(null);
    } // <init>()

    
Constructs an entity manager that shares the specified entity
declarations during each parse.

REVISIT: We might want to think about the "right"
way to expose the list of declared entities. For now, the knowledge
how to access the entity declarations is implicit.
/**
     * Constructs an entity manager that shares the specified entity
     * declarations during each parse.
     * <p>
     * <strong>REVISIT:</strong> We might want to think about the "right"
     * way to expose the list of declared entities. For now, the knowledge
     * how to access the entity declarations is implicit.
     */
    public XMLEntityManager(XMLEntityManager entityManager) {

        // save shared entity declarations
        fDeclaredEntities = entityManager != null
                          ? entityManager.getDeclaredEntities() : null;

        setScannerVersion(Constants.XML_VERSION_1_0);
    } // <init>(XMLEntityManager)

    //
    // Public methods
    //

    
Sets whether the document entity is standalone.
Params:
standalone – True if document entity is standalone./**
     * Sets whether the document entity is standalone.
     *
     * @param standalone True if document entity is standalone.
     */
    public void setStandalone(boolean standalone) {
        fStandalone = standalone;
    } // setStandalone(boolean)

    
Returns true if the document entity is standalone. /** Returns true if the document entity is standalone. */
    public boolean isStandalone() {
        return fStandalone;
    } // isStandalone():boolean
    
    
Notifies the entity manager that the current document 
being processed contains parameter entity references.
/** 
     * Notifies the entity manager that the current document 
     * being processed contains parameter entity references.
     */
    final void notifyHasPEReferences() {
        fHasPEReferences = true;
    } // notifyHasPEReferences
    
    
Returns true if the document contains parameter entity references.
/** 
     * Returns true if the document contains parameter entity references.
     */
    final boolean hasPEReferences() {
        return fHasPEReferences;
    } // hasPEReferences():boolean

    
Sets the entity handler. When an entity starts and ends, the
entity handler is notified of the change.
Params:
entityHandler – The new entity handler./**
     * Sets the entity handler. When an entity starts and ends, the
     * entity handler is notified of the change.
     *
     * @param entityHandler The new entity handler.
     */
    public void setEntityHandler(XMLEntityHandler entityHandler) {
        fEntityHandler = entityHandler;
    } // setEntityHandler(XMLEntityHandler)

    // this simply returns the fResourceIdentifier object;
    // this should only be used with caution by callers that
    // carefully manage the entity manager's behaviour, so that 
    // this doesn't returning meaningless or misleading data.
    // @return  a reference to the current fResourceIdentifier object
    public XMLResourceIdentifier getCurrentResourceIdentifier() {
        return fResourceIdentifier;
    }

    // this simply returns the fCurrentEntity object;
    // this should only be used with caution by callers that
    // carefully manage the entity manager's behaviour, so that 
    // this doesn't returning meaningless or misleading data.
    // @return  a reference to the current fCurrentEntity object
    public ScannedEntity getCurrentEntity() {
        return fCurrentEntity;
    }

    
Adds an internal entity declaration.

Note: This method ignores subsequent entity
declarations.

Note: The name should be a unique symbol. The
SymbolTable can be used for this purpose.
Params:
name – The name of the entity.
text – The text of the entity.
paramEntityRefs – Count of direct and indirect references to parameter entities in the value of the entity.
See Also:
SymbolTable/**
     * Adds an internal entity declaration.
     * <p>
     * <strong>Note:</strong> This method ignores subsequent entity
     * declarations.
     * <p>
     * <strong>Note:</strong> The name should be a unique symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @param name The name of the entity.
     * @param text The text of the entity.
     * @param paramEntityRefs Count of direct and indirect references to parameter entities in the value of the entity.
     *
     * @see SymbolTable
     */
    public void addInternalEntity(String name, String text, int paramEntityRefs) {
        if (!fEntities.containsKey(name)) {
            Entity entity = new InternalEntity(name, text, fInExternalSubset, paramEntityRefs);
            fEntities.put(name, entity);
        }
        else{
            if(fWarnDuplicateEntityDef){
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                             "MSG_DUPLICATE_ENTITY_DEFINITION",
                                             new Object[]{ name },
                                             XMLErrorReporter.SEVERITY_WARNING );
            }
        }

    } // addInternalEntity(String,String,int)    
    
    
Adds an internal entity declaration.

Note: This method ignores subsequent entity
declarations.

Note: The name should be a unique symbol. The
SymbolTable can be used for this purpose.
Params:
name – The name of the entity.
text – The text of the entity.
See Also:
SymbolTable/**
     * Adds an internal entity declaration.
     * <p>
     * <strong>Note:</strong> This method ignores subsequent entity
     * declarations.
     * <p>
     * <strong>Note:</strong> The name should be a unique symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @param name The name of the entity.
     * @param text The text of the entity.
     *
     * @see SymbolTable
     */
    public void addInternalEntity(String name, String text) {
        addInternalEntity(name, text, 0);
    } // addInternalEntity(String,String)
    
    
Returns the number of direct and indirect references to parameter 
entities in the value of the entity. This value will only be
non-zero for an internal parameter entity.
Params:
entityName – The name of the entity to check.
Returns:
Count of direct and indirect references to parameter entities in the value of the entity/**
     * Returns the number of direct and indirect references to parameter 
     * entities in the value of the entity. This value will only be
     * non-zero for an internal parameter entity.
     * 
     * @param entityName The name of the entity to check.
     * @return Count of direct and indirect references to parameter entities in the value of the entity
     */
    public int getParamEntityRefCount(String entityName) {
        if (entityName != null && 
            entityName.length() > 0 && 
            entityName.charAt(0) == '%') {
            final Entity entity = (Entity) fEntities.get(entityName);
            if (entity != null && !entity.isExternal()) {
                return ((InternalEntity) entity).paramEntityRefs;
            }
        }
        return 0;
    } // getParamEntityRefCount(String)
    
    
Adds an external entity declaration.

Note: This method ignores subsequent entity
declarations.

Note: The name should be a unique symbol. The
SymbolTable can be used for this purpose.
Params:
name –         The name of the entity.
publicId –     The public identifier of the entity.
literalSystemId –     The system identifier of the entity.
baseSystemId – The base system identifier of the entity.
                    This is the system identifier of the entity
                    where the entity being added and
                    is used to expand the system identifier when
                    the system identifier is a relative URI.
                    When null the system identifier of the first
                    external entity on the stack is used instead.
See Also:
SymbolTable/**
     * Adds an external entity declaration.
     * <p>
     * <strong>Note:</strong> This method ignores subsequent entity
     * declarations.
     * <p>
     * <strong>Note:</strong> The name should be a unique symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @param name         The name of the entity.
     * @param publicId     The public identifier of the entity.
     * @param literalSystemId     The system identifier of the entity.
     * @param baseSystemId The base system identifier of the entity.
     *                     This is the system identifier of the entity
     *                     where <em>the entity being added</em> and
     *                     is used to expand the system identifier when
     *                     the system identifier is a relative URI.
     *                     When null the system identifier of the first
     *                     external entity on the stack is used instead.
     *
     * @see SymbolTable
     */
    public void addExternalEntity(String name,
                                  String publicId, String literalSystemId,
                                  String baseSystemId) throws IOException {
        if (!fEntities.containsKey(name)) {
            if (baseSystemId == null) {
                // search for the first external entity on the stack
                int size = fEntityStack.size();
                if (size == 0 && fCurrentEntity != null && fCurrentEntity.entityLocation != null) {
                    baseSystemId = fCurrentEntity.entityLocation.getExpandedSystemId();
                }
                for (int i = size - 1; i >= 0 ; i--) {
                    ScannedEntity externalEntity =
                        (ScannedEntity)fEntityStack.elementAt(i);
                    if (externalEntity.entityLocation != null && externalEntity.entityLocation.getExpandedSystemId() != null) {
                        baseSystemId = externalEntity.entityLocation.getExpandedSystemId();
                        break;
                    }
                }
            }
            Entity entity = new ExternalEntity(name,
                new XMLEntityDescriptionImpl(name, publicId, literalSystemId, baseSystemId, 
                expandSystemId(literalSystemId, baseSystemId, false)), null, fInExternalSubset);
            fEntities.put(name, entity);
        }
        else{
            if(fWarnDuplicateEntityDef){
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                             "MSG_DUPLICATE_ENTITY_DEFINITION",
                                             new Object[]{ name },
                                             XMLErrorReporter.SEVERITY_WARNING );
            }
        }

    } // addExternalEntity(String,String,String,String)

    
Checks whether an entity given by name is external.
Params:
entityName – The name of the entity to check.
Returns:
True if the entity is external, false otherwise
(including when the entity is not declared)./**
     * Checks whether an entity given by name is external.
     *
     * @param entityName The name of the entity to check.
     * @return True if the entity is external, false otherwise
     * (including when the entity is not declared).
     */
    public boolean isExternalEntity(String entityName) {

        Entity entity = (Entity)fEntities.get(entityName);
        if (entity == null) {
            return false;
        }
        return entity.isExternal();
    }

    
Checks whether the declaration of an entity given by name is 
// in the external subset. 
Params:
entityName – The name of the entity to check.
Returns:
True if the entity was declared in the external subset, false otherwise
          (including when the entity is not declared)./**
     * Checks whether the declaration of an entity given by name is 
     // in the external subset. 
     *
     * @param entityName The name of the entity to check.
     * @return True if the entity was declared in the external subset, false otherwise
     *           (including when the entity is not declared).
     */
    public boolean isEntityDeclInExternalSubset(String entityName) {

        Entity entity = (Entity)fEntities.get(entityName);
        if (entity == null) {
            return false;
        }
        return entity.isEntityDeclInExternalSubset();
    }

    
Adds an unparsed entity declaration.

Note: This method ignores subsequent entity
declarations.

Note: The name should be a unique symbol. The
SymbolTable can be used for this purpose.
Params:
name –     The name of the entity.
publicId – The public identifier of the entity.
systemId – The system identifier of the entity.
notation – The name of the notation.
See Also:
SymbolTable/**
     * Adds an unparsed entity declaration.
     * <p>
     * <strong>Note:</strong> This method ignores subsequent entity
     * declarations.
     * <p>
     * <strong>Note:</strong> The name should be a unique symbol. The
     * SymbolTable can be used for this purpose.
     *
     * @param name     The name of the entity.
     * @param publicId The public identifier of the entity.
     * @param systemId The system identifier of the entity.
     * @param notation The name of the notation.
     *
     * @see SymbolTable
     */
    public void addUnparsedEntity(String name,
                                  String publicId, String systemId,
                                  String baseSystemId, String notation) {
        if (!fEntities.containsKey(name)) {
            Entity entity = new ExternalEntity(name, 
                new XMLEntityDescriptionImpl(name, publicId, systemId, baseSystemId, null), 
                notation, fInExternalSubset);
            fEntities.put(name, entity);
        }
        else{
            if(fWarnDuplicateEntityDef){
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                             "MSG_DUPLICATE_ENTITY_DEFINITION",
                                             new Object[]{ name },
                                             XMLErrorReporter.SEVERITY_WARNING );
            }
        }
    } // addUnparsedEntity(String,String,String,String)

    
Checks whether an entity given by name is unparsed.
Params:
entityName – The name of the entity to check.
Returns:
True if the entity is unparsed, false otherwise
         (including when the entity is not declared)./**
     * Checks whether an entity given by name is unparsed.
     *
     * @param entityName The name of the entity to check.
     * @return True if the entity is unparsed, false otherwise
     *          (including when the entity is not declared).
     */
    public boolean isUnparsedEntity(String entityName) {

        Entity entity = (Entity)fEntities.get(entityName);
        if (entity == null) {
            return false;
        }
        return entity.isUnparsed();
    }

    
Checks whether an entity given by name is declared.
Params:
entityName – The name of the entity to check.
Returns:
True if the entity is declared, false otherwise./**
     * Checks whether an entity given by name is declared.
     *
     * @param entityName The name of the entity to check.
     * @return True if the entity is declared, false otherwise.
     */
    public boolean isDeclaredEntity(String entityName) {

        Entity entity = (Entity)fEntities.get(entityName);
        return entity != null;
    }

    
Resolves the specified public and system identifiers. This
method first attempts to resolve the entity based on the
EntityResolver registered by the application. If no entity
resolver is registered or if the registered entity handler
is unable to resolve the entity, then default entity
resolution will occur.
Params:
resourceIdentifier – The XMLResourceIdentifier for the resource to resolve.
Throws:
IOException –  Thrown on i/o error.
XNIException – Thrown by entity resolver to signal an error.
Returns:
Returns an input source that wraps the resolved entity.
        This method will never return null./**
     * Resolves the specified public and system identifiers. This
     * method first attempts to resolve the entity based on the
     * EntityResolver registered by the application. If no entity
     * resolver is registered or if the registered entity handler
     * is unable to resolve the entity, then default entity
     * resolution will occur.
     *
     * @param resourceIdentifier The XMLResourceIdentifier for the resource to resolve.
     *
     * @return Returns an input source that wraps the resolved entity.
     *         This method will never return null.
     *
     * @throws IOException  Thrown on i/o error.
     * @throws XNIException Thrown by entity resolver to signal an error.
     */
    public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)
            throws IOException, XNIException {
        if(resourceIdentifier == null ) return null;
        String publicId = resourceIdentifier.getPublicId();
        String literalSystemId = resourceIdentifier.getLiteralSystemId();
        String baseSystemId = resourceIdentifier.getBaseSystemId();
        String expandedSystemId = resourceIdentifier.getExpandedSystemId();
        // if no base systemId given, assume that it's relative
        // to the systemId of the current scanned entity
        // Sometimes the system id is not (properly) expanded.
        // We need to expand the system id if:
        // a. the expanded one was null; or
        // b. the base system id was null, but becomes non-null from the current entity.
        boolean needExpand = (expandedSystemId == null);
        // REVISIT:  why would the baseSystemId ever be null?  if we
        // didn't have to make this check we wouldn't have to reuse the
        // fXMLResourceIdentifier object...
        if (baseSystemId == null && fCurrentEntity != null && fCurrentEntity.entityLocation != null) {
            baseSystemId = fCurrentEntity.entityLocation.getExpandedSystemId();
            if (baseSystemId != null)
                needExpand = true;
        }
        
        // give the entity resolver a chance
        XMLInputSource xmlInputSource = null;
        if (fEntityResolver != null) {
            if (needExpand) {
                expandedSystemId = expandSystemId(literalSystemId, baseSystemId, false);
            }
            resourceIdentifier.setBaseSystemId(baseSystemId);
            resourceIdentifier.setExpandedSystemId(expandedSystemId);
            xmlInputSource = fEntityResolver.resolveEntity(resourceIdentifier);
        }

        // do default resolution
        // REVISIT: what's the correct behavior if the user provided an entity
        // resolver (fEntityResolver != null), but resolveEntity doesn't return
        // an input source (xmlInputSource == null)?
        // do we do default resolution, or do we just return null? -SG
        if (xmlInputSource == null) {
            // REVISIT: when systemId is null, I think we should return null.
            //          is this the right solution? -SG
            //if (systemId != null)
            xmlInputSource = new XMLInputSource(publicId, literalSystemId, baseSystemId);
        }

        if (DEBUG_RESOLVER) {
            System.err.println("XMLEntityManager.resolveEntity(" + publicId + ")");
            System.err.println(" = " + xmlInputSource);
        }

        return xmlInputSource;

    } // resolveEntity(XMLResourceIdentifier):XMLInputSource

    
Starts a named entity.
Params:
entityName – The name of the entity to start.
literal –    True if this entity is started within a literal
                  value.
Throws:
IOException –  Thrown on i/o error.
XNIException – Thrown by entity handler to signal an error./**
     * Starts a named entity.
     *
     * @param entityName The name of the entity to start.
     * @param literal    True if this entity is started within a literal
     *                   value.
     *
     * @throws IOException  Thrown on i/o error.
     * @throws XNIException Thrown by entity handler to signal an error.
     */
    public void startEntity(String entityName, boolean literal)
        throws IOException, XNIException {

        // was entity declared?
        Entity entity = (Entity)fEntities.get(entityName);
        if (entity == null) {
            if (fEntityHandler != null) {
                String encoding = null;
                fResourceIdentifier.clear();
                fEntityAugs.removeAllItems();
                fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                fEntityHandler.startEntity(entityName, fResourceIdentifier, encoding, fEntityAugs);
                fEntityAugs.removeAllItems();
                fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                fEntityHandler.endEntity(entityName, fEntityAugs);
            }
            return;
        }

        // should we skip external entities?
        boolean external = entity.isExternal();
        if (external && (fValidationManager == null || !fValidationManager.isCachedDTD())) {
            boolean unparsed = entity.isUnparsed();
            boolean parameter = entityName.startsWith("%");
            boolean general = !parameter;
            if (unparsed || (general && !fExternalGeneralEntities) ||
                (parameter && !fExternalParameterEntities)) {
                if (fEntityHandler != null) {
                    fResourceIdentifier.clear();
                    final String encoding = null;
                    ExternalEntity externalEntity = (ExternalEntity)entity;
                    //REVISIT:  since we're storing expandedSystemId in the
                    // externalEntity, how could this have got here if it wasn't already
                    // expanded??? - neilg
                    String extLitSysId = (externalEntity.entityLocation != null ? externalEntity.entityLocation.getLiteralSystemId() : null);
                    String extBaseSysId = (externalEntity.entityLocation != null ? externalEntity.entityLocation.getBaseSystemId() : null);
                    String expandedSystemId = expandSystemId(extLitSysId, extBaseSysId, false);
                    fResourceIdentifier.setValues(
                            (externalEntity.entityLocation != null ? externalEntity.entityLocation.getPublicId() : null),
                            extLitSysId, extBaseSysId, expandedSystemId);
                    fEntityAugs.removeAllItems();
                    fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                    fEntityHandler.startEntity(entityName, fResourceIdentifier, encoding, fEntityAugs);
                    fEntityAugs.removeAllItems();
                    fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                    fEntityHandler.endEntity(entityName, fEntityAugs);
                }
                return;
            }
        }

        // is entity recursive?
        int size = fEntityStack.size();
        for (int i = size; i >= 0; i--) {
            Entity activeEntity = i == size
                                ? fCurrentEntity
                                : (Entity)fEntityStack.elementAt(i);
            if (activeEntity.name == entityName) {
                StringBuffer path = new StringBuffer(entityName);
                for (int j = i + 1; j < size; j++) {
                    activeEntity = (Entity)fEntityStack.elementAt(j);
                    path.append(" -> ");
                    path.append(activeEntity.name);
                }
                path.append(" -> ");
                path.append(fCurrentEntity.name);
                path.append(" -> ");
                path.append(entityName);
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                           "RecursiveReference",
                                           new Object[] { entityName, path.toString() },
                                           XMLErrorReporter.SEVERITY_FATAL_ERROR);
                if (fEntityHandler != null) {
                    fResourceIdentifier.clear();
                    final String encoding = null;
                    if (external) {
                        ExternalEntity externalEntity = (ExternalEntity)entity;
                        // REVISIT:  for the same reason above...
                        String extLitSysId = (externalEntity.entityLocation != null ? externalEntity.entityLocation.getLiteralSystemId() : null);
                        String extBaseSysId = (externalEntity.entityLocation != null ? externalEntity.entityLocation.getBaseSystemId() : null);
                        String expandedSystemId = expandSystemId(extLitSysId, extBaseSysId, false);
                        fResourceIdentifier.setValues(
                                (externalEntity.entityLocation != null ? externalEntity.entityLocation.getPublicId() : null),
                                extLitSysId, extBaseSysId, expandedSystemId);
                    }
                    fEntityAugs.removeAllItems();
                    fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                    fEntityHandler.startEntity(entityName, fResourceIdentifier, encoding, fEntityAugs);
                    fEntityAugs.removeAllItems();
                    fEntityAugs.putItem(Constants.ENTITY_SKIPPED, Boolean.TRUE);
                    fEntityHandler.endEntity(entityName, fEntityAugs);
                }
                return;
            }
        }

        // resolve external entity
        XMLInputSource xmlInputSource = null;
        if (external) {
            ExternalEntity externalEntity = (ExternalEntity)entity;
            xmlInputSource = resolveEntity(externalEntity.entityLocation);
        }

        // wrap internal entity
        else {
            InternalEntity internalEntity = (InternalEntity)entity;
            Reader reader = new StringReader(internalEntity.text);
            xmlInputSource = new XMLInputSource(null, null, null, reader, null);
        }

        // start the entity
        startEntity(entityName, xmlInputSource, literal, external);

    } // startEntity(String,boolean)

    
Starts the document entity. The document entity has the "[xml]"
pseudo-name.
Params:
xmlInputSource – The input source of the document entity.
Throws:
IOException –  Thrown on i/o error.
XNIException – Thrown by entity handler to signal an error./**
     * Starts the document entity. The document entity has the "[xml]"
     * pseudo-name.
     *
     * @param xmlInputSource The input source of the document entity.
     *
     * @throws IOException  Thrown on i/o error.
     * @throws XNIException Thrown by entity handler to signal an error.
     */
    public void startDocumentEntity(XMLInputSource xmlInputSource)
        throws IOException, XNIException {
        startEntity(XMLEntity, xmlInputSource, false, true);
    } // startDocumentEntity(XMLInputSource)

    
Starts the DTD entity. The DTD entity has the "[dtd]"
pseudo-name.
Params:
xmlInputSource – The input source of the DTD entity.
Throws:
IOException –  Thrown on i/o error.
XNIException – Thrown by entity handler to signal an error./**
     * Starts the DTD entity. The DTD entity has the "[dtd]"
     * pseudo-name.
     *
     * @param xmlInputSource The input source of the DTD entity.
     *
     * @throws IOException  Thrown on i/o error.
     * @throws XNIException Thrown by entity handler to signal an error.
     */
    public void startDTDEntity(XMLInputSource xmlInputSource)
        throws IOException, XNIException {
        startEntity(DTDEntity, xmlInputSource, false, true);
    } // startDTDEntity(XMLInputSource)

    // indicate start of external subset so that
    // location of entity decls can be tracked
    public void startExternalSubset() {
        fInExternalSubset = true;
    }

    public void endExternalSubset() {
        fInExternalSubset = false;
    }

    
Starts an entity.

This method can be used to insert an application defined XML
entity stream into the parsing stream.
Params:
name –           The name of the entity.
xmlInputSource – The input source of the entity.
literal –        True if this entity is started within a
                      literal value.
isExternal –    whether this entity should be treated as an internal or external entity.
Throws:
IOException –  Thrown on i/o error.
XNIException – Thrown by entity handler to signal an error./**
     * Starts an entity.
     * <p>
     * This method can be used to insert an application defined XML
     * entity stream into the parsing stream.
     *
     * @param name           The name of the entity.
     * @param xmlInputSource The input source of the entity.
     * @param literal        True if this entity is started within a
     *                       literal value.
     * @param isExternal    whether this entity should be treated as an internal or external entity.
     *
     * @throws IOException  Thrown on i/o error.
     * @throws XNIException Thrown by entity handler to signal an error.
     */
    public void startEntity(String name,
                            XMLInputSource xmlInputSource,
                            boolean literal, boolean isExternal)
        throws IOException, XNIException {

        String encoding = setupCurrentEntity(name, xmlInputSource, literal, isExternal);

        // when entity expansion limit is set by the Application, we need to
        // check for the entity expansion limit set by the parser, if number of entity
        // expansions exceeds the entity expansion limit, parser will throw fatal error.
        // Note that this is intentionally unbalanced; it counts
        // the number of expansions *per document*.
        if (fSecurityManager != null) {
            fEntityExpansionCount += getParamEntityRefCount(name);
            if (fEntityExpansionCount++ > fEntityExpansionLimit) {
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                        "EntityExpansionLimitExceeded",
                        new Object[]{new Integer(fEntityExpansionLimit) },
                        XMLErrorReporter.SEVERITY_FATAL_ERROR );
                // is there anything better to do than reset the counter?
                // at least one can envision debugging applications where this might
                // be useful...
                fEntityExpansionCount = 0;
            }
        }
        
        // call handler
        if (fEntityHandler != null) {
            fEntityHandler.startEntity(name, fResourceIdentifier, encoding, null);
        }

    } // startEntity(String,XMLInputSource)

    
This method uses the passed-in XMLInputSource to make 
fCurrentEntity usable for reading.
Params:
name –  name of the entity (XML is it's the document entity)
xmlInputSource –    the input source, with sufficient information
     to begin scanning characters.
literal –        True if this entity is started within a
                      literal value.
isExternal –    whether this entity should be treated as an internal or external entity.
Throws:
IOException –  if anything can't be read
 XNIException    If any parser-specific goes wrong.
Returns:
the encoding of the new entity or null if a character stream was employed/**
     * This method uses the passed-in XMLInputSource to make 
     * fCurrentEntity usable for reading.
     * @param name  name of the entity (XML is it's the document entity)
     * @param xmlInputSource    the input source, with sufficient information
     *      to begin scanning characters.
     * @param literal        True if this entity is started within a
     *                       literal value.
     * @param isExternal    whether this entity should be treated as an internal or external entity.
     * @throws IOException  if anything can't be read
     *  XNIException    If any parser-specific goes wrong.
     * @return the encoding of the new entity or null if a character stream was employed
     */
    public String setupCurrentEntity(String name, XMLInputSource xmlInputSource,
                boolean literal, boolean isExternal)
            throws IOException, XNIException {
        // get information

        final String publicId = xmlInputSource.getPublicId();
        String literalSystemId = xmlInputSource.getSystemId();
        String baseSystemId = xmlInputSource.getBaseSystemId();
        String encoding = xmlInputSource.getEncoding();
        final boolean encodingExternallySpecified = (encoding != null);
        Boolean isBigEndian = null;
        fTempByteBuffer = null;

        // create reader
        InputStream stream = null;
        Reader reader = xmlInputSource.getCharacterStream();
        // First chance checking strict URI
        String expandedSystemId = expandSystemId(literalSystemId, baseSystemId, fStrictURI);
        if (baseSystemId == null) {
            baseSystemId = expandedSystemId;
        }
        if (reader == null) {
            stream = xmlInputSource.getByteStream();
            if (stream == null) {
                URL location = new URL(expandedSystemId);
                URLConnection connect = location.openConnection();
                if (!(connect instanceof HttpURLConnection)) {
                    stream = connect.getInputStream();
                }
                else {
                    boolean followRedirects = true;
                    
                    // setup URLConnection if we have an HTTPInputSource
                    if (xmlInputSource instanceof HTTPInputSource) {
                        final HttpURLConnection urlConnection = (HttpURLConnection) connect;
                        final HTTPInputSource httpInputSource = (HTTPInputSource) xmlInputSource;
                        
                        // set request properties
                        Iterator propIter = httpInputSource.getHTTPRequestProperties();
                        while (propIter.hasNext()) {
                            Map.Entry entry = (Map.Entry) propIter.next();
                            urlConnection.setRequestProperty((String) entry.getKey(), (String) entry.getValue());
                        }
                        
                        // set preference for redirection
                        followRedirects = httpInputSource.getFollowHTTPRedirects();
                        if (!followRedirects) {
                            urlConnection.setInstanceFollowRedirects(followRedirects);
                        }
                    }
                    
                    stream = connect.getInputStream();
                    
                    // REVISIT: If the URLConnection has external encoding
                    // information, we should be reading it here. It's located
                    // in the charset parameter of Content-Type. -- mrglavas
                    
                    if (followRedirects) {
                        String redirect = connect.getURL().toString();
                        // E43: Check if the URL was redirected, and then
                        // update literal and expanded system IDs if needed.
                        if (!redirect.equals(expandedSystemId)) {
                            literalSystemId = redirect;
                            expandedSystemId = redirect;
                        }
                    }
                }
            }
            // wrap this stream in RewindableInputStream
            RewindableInputStream rewindableStream = new RewindableInputStream(stream);
            stream = rewindableStream;

            // perform auto-detect of encoding if necessary
            if (encoding == null) {
                // read first four bytes and determine encoding
                final byte[] b4 = new byte[4];
                int count = 0;
                for (; count<4; count++ ) {
                    b4[count] = (byte)rewindableStream.readAndBuffer();
                }
                if (count == 4) {
                    final EncodingInfo info = getEncodingInfo(b4, count);
                    encoding = info.autoDetectedEncoding;
                    final String readerEncoding = info.readerEncoding;
                    isBigEndian = info.isBigEndian;
                    stream.reset();
                    if (info.hasBOM) {
                        // Special case UTF-8 files with BOM created by Microsoft
                        // tools. It's more efficient to consume the BOM than make
                        // the reader perform extra checks. -Ac
                        if (readerEncoding == "UTF-8") {
                            // UTF-8 BOM: 0xEF 0xBB 0xBF
                            stream.skip(3);
                        }
                        // It's also more efficient to consume the UTF-16 BOM.
                        else if (readerEncoding == "UTF-16") {
                            // UTF-16 BE BOM: 0xFE 0xFF 
                            // UTF-16 LE BOM: 0xFF 0xFE
                            stream.skip(2);
                        }
                    }
                    reader = createReader(stream, readerEncoding, isBigEndian);
                }
                else {
                    reader = createReader(stream, encoding, isBigEndian);
                }
            }

            // use specified encoding
            else {
                encoding = encoding.toUpperCase(Locale.ENGLISH);
                
                // If encoding is UTF-8, consume BOM if one is present.
                if (encoding.equals("UTF-8")) {
                    final int[] b3 = new int[3];
                    int count = 0;
                    for (; count < 3; ++count) {
                        b3[count] = rewindableStream.readAndBuffer();
                        if (b3[count] == -1)
                            break;
                    }
                    if (count == 3) {
                        if (b3[0] != 0xEF || b3[1] != 0xBB || b3[2] != 0xBF) {
                            // First three bytes are not BOM, so reset.
                            stream.reset();
                        }
                    }
                    else {
                        stream.reset();
                    }
                    reader = createReader(stream, "UTF-8", isBigEndian);
                }
                // If encoding is UTF-16, we still need to read the first 
                // four bytes, in order to discover the byte order.
                else if (encoding.equals("UTF-16")) {
                    final int[] b4 = new int[4];
                    int count = 0;
                    for (; count < 4; ++count) {
                        b4[count] = rewindableStream.readAndBuffer();
                        if (b4[count] == -1)
                            break;
                    }
                    stream.reset();
                    if (count >= 2) {
                        final int b0 = b4[0];
                        final int b1 = b4[1];
                        if (b0 == 0xFE && b1 == 0xFF) {
                            // UTF-16, big-endian
                            isBigEndian = Boolean.TRUE;
                            stream.skip(2);
                        }
                        else if (b0 == 0xFF && b1 == 0xFE) {
                            // UTF-16, little-endian
                            isBigEndian = Boolean.FALSE;
                            stream.skip(2);
                        }
                        else if (count == 4) {
                            final int b2 = b4[2];
                            final int b3 = b4[3];
                            if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F) {
                                // UTF-16, big-endian, no BOM
                                isBigEndian = Boolean.TRUE;
                            }
                            if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00) {
                                // UTF-16, little-endian, no BOM
                                isBigEndian = Boolean.FALSE;
                            }
                        }
                    }
                    reader = createReader(stream, "UTF-16", isBigEndian);
                }
                // If encoding is UCS-4, we still need to read the first four bytes
                // in order to discover the byte order.
                else if (encoding.equals("ISO-10646-UCS-4")) {
                    final int[] b4 = new int[4];
                    int count = 0;
                    for (; count < 4; ++count) {
                        b4[count] = rewindableStream.readAndBuffer();
                        if (b4[count] == -1)
                            break;
                    }
                    stream.reset();

                    // Ignore unusual octet order for now.
                    if (count == 4) {
                        // UCS-4, big endian (1234)
                        if (b4[0] == 0x00 && b4[1] == 0x00 && b4[2] == 0x00 && b4[3] == 0x3C) {
                            isBigEndian = Boolean.TRUE;
                        }
                        // UCS-4, little endian (1234)
                        else if (b4[0] == 0x3C && b4[1] == 0x00 && b4[2] == 0x00 && b4[3] == 0x00) {
                            isBigEndian = Boolean.FALSE;
                        }
                    }
                    reader = createReader(stream, encoding, isBigEndian);
                }
                // If encoding is UCS-2, we still need to read the first four bytes
                // in order to discover the byte order.
                else if (encoding.equals("ISO-10646-UCS-2")) {
                    final int[] b4 = new int[4];
                    int count = 0;
                    for (; count < 4; ++count) {
                        b4[count] = rewindableStream.readAndBuffer();
                        if (b4[count] == -1)
                            break;
                    }
                    stream.reset();

                    if (count == 4) {
                        // UCS-2, big endian
                        if (b4[0] == 0x00 && b4[1] == 0x3C && b4[2] == 0x00 && b4[3] == 0x3F) {
                            isBigEndian = Boolean.TRUE;
                        }
                        // UCS-2, little endian
                        else if (b4[0] == 0x3C && b4[1] == 0x00 && b4[2] == 0x3F && b4[3] == 0x00) {
                            isBigEndian = Boolean.FALSE;
                        }
                    }
                    reader = createReader(stream, encoding, isBigEndian);
                }
                else {
                    reader = createReader(stream, encoding, isBigEndian);
                }
            }

            // read one character at a time so we don't jump too far
            // ahead, converting characters from the byte stream in
            // the wrong encoding
            if (DEBUG_ENCODINGS) {
                System.out.println("$$$ no longer wrapping reader in OneCharReader");
            }
            //reader = new OneCharReader(reader);
        }

        // We've seen a new Reader.
        // Push it on the stack so we can close it later.
        fReaderStack.push(reader);

        // push entity on stack
        if (fCurrentEntity != null) {
            fEntityStack.push(fCurrentEntity);
        }

        // create entity
        fCurrentEntity = new ScannedEntity(name,
                new XMLResourceIdentifierImpl(publicId, literalSystemId, baseSystemId, expandedSystemId),
                stream, reader, fTempByteBuffer, encoding, literal, false, isExternal);
		fCurrentEntity.setEncodingExternallySpecified(encodingExternallySpecified);
        fEntityScanner.setCurrentEntity(fCurrentEntity);
        fResourceIdentifier.setValues(publicId, literalSystemId, baseSystemId, expandedSystemId);
        return encoding;
    } //setupCurrentEntity(String, XMLInputSource, boolean, boolean):  String

    // set version of scanner to use
    public void setScannerVersion(short version) {
        if(version == Constants.XML_VERSION_1_0) {
            if(fXML10EntityScanner == null) {
                fXML10EntityScanner = new XMLEntityScanner();
            }
			fXML10EntityScanner.reset(fSymbolTable, this, fErrorReporter);
            fEntityScanner = fXML10EntityScanner;
            fEntityScanner.setCurrentEntity(fCurrentEntity);
        } else {
            if(fXML11EntityScanner == null) {
                fXML11EntityScanner = new XML11EntityScanner();
            }
			fXML11EntityScanner.reset(fSymbolTable, this, fErrorReporter);
            fEntityScanner = fXML11EntityScanner;
            fEntityScanner.setCurrentEntity(fCurrentEntity);
        }
    } // setScannerVersion(short)

    
Returns the entity scanner. /** Returns the entity scanner. */
    public XMLEntityScanner getEntityScanner() {
        if(fEntityScanner == null) {
            // default to 1.0
            if(fXML10EntityScanner == null) {
                fXML10EntityScanner = new XMLEntityScanner();
            }
            fXML10EntityScanner.reset(fSymbolTable, this, fErrorReporter);
            fEntityScanner = fXML10EntityScanner;
        }
        return fEntityScanner;
    } // getEntityScanner():XMLEntityScanner

    // A stack containing all the open readers
    protected Stack fReaderStack = new Stack();

    
Close all opened InputStreams and Readers opened by this parser.
/**
     * Close all opened InputStreams and Readers opened by this parser.
     */
    public void closeReaders() {
        // close all readers
        for (int i = fReaderStack.size()-1; i >= 0; i--) {
            try {
                ((Reader)fReaderStack.pop()).close();
            } catch (IOException e) {
                // ignore
            }
        }
    }

    //
    // XMLComponent methods
    //

    
Resets the component. The component can query the component manager
about any features and properties that affect the operation of the
component.
Params:
componentManager – The component manager.
Throws:
SAXException – Thrown by component on initialization error.
                     For example, if a feature or property is
                     required for the operation of the component, the
                     component manager may throw a
                     SAXNotRecognizedException or a
                     SAXNotSupportedException./**
     * Resets the component. The component can query the component manager
     * about any features and properties that affect the operation of the
     * component.
     *
     * @param componentManager The component manager.
     *
     * @throws SAXException Thrown by component on initialization error.
     *                      For example, if a feature or property is
     *                      required for the operation of the component, the
     *                      component manager may throw a
     *                      SAXNotRecognizedException or a
     *                      SAXNotSupportedException.
     */
    public void reset(XMLComponentManager componentManager)
        throws XMLConfigurationException {
        	
		boolean parser_settings;
		try {
				parser_settings = componentManager.getFeature(PARSER_SETTINGS);
		} catch (XMLConfigurationException e) {
				parser_settings = true;
		}

		if (!parser_settings) {
			// parser settings have not been changed
			reset();
			return;
		}

        // sax features
        try {
            fValidation = componentManager.getFeature(VALIDATION);
        }
        catch (XMLConfigurationException e) {
            fValidation = false;
        }
        try {
            fExternalGeneralEntities = componentManager.getFeature(EXTERNAL_GENERAL_ENTITIES);
        }
        catch (XMLConfigurationException e) {
            fExternalGeneralEntities = true;
        }
        try {
            fExternalParameterEntities = componentManager.getFeature(EXTERNAL_PARAMETER_ENTITIES);
        }
        catch (XMLConfigurationException e) {
            fExternalParameterEntities = true;
        }

        // xerces features
        try {
            fAllowJavaEncodings = componentManager.getFeature(ALLOW_JAVA_ENCODINGS);
        }
        catch (XMLConfigurationException e) {
            fAllowJavaEncodings = false;
        }

        try {
            fWarnDuplicateEntityDef = componentManager.getFeature(WARN_ON_DUPLICATE_ENTITYDEF);
        }
        catch (XMLConfigurationException e) {
            fWarnDuplicateEntityDef = false;
        }

        try {
            fStrictURI = componentManager.getFeature(STANDARD_URI_CONFORMANT);
        }
        catch (XMLConfigurationException e) {
            fStrictURI = false;
        }

        // xerces properties
        fSymbolTable = (SymbolTable)componentManager.getProperty(SYMBOL_TABLE);
        fErrorReporter = (XMLErrorReporter)componentManager.getProperty(ERROR_REPORTER);
        try {
            fEntityResolver = (XMLEntityResolver)componentManager.getProperty(ENTITY_RESOLVER);
        }
        catch (XMLConfigurationException e) {
            fEntityResolver = null;
        }
        try {
            fValidationManager = (ValidationManager)componentManager.getProperty(VALIDATION_MANAGER);
        }
        catch (XMLConfigurationException e) {
            fValidationManager = null;
        }
        try {
            fSecurityManager = (SecurityManager)componentManager.getProperty(SECURITY_MANAGER);
        }
        catch (XMLConfigurationException e) {
            fSecurityManager = null;
        }

        // reset general state
        reset();
        
    } // reset(XMLComponentManager)

    // reset general state.  Should not be called other than by
    // a class acting as a component manager but not
    // implementing that interface for whatever reason.
    public void reset() {
        fEntityExpansionLimit = (fSecurityManager != null)?fSecurityManager.getEntityExpansionLimit():0;

        // initialize state
        fStandalone = false;
        fHasPEReferences = false;
        fEntities.clear();
        fEntityStack.removeAllElements();
        fEntityExpansionCount = 0;

        fCurrentEntity = null;
        // reset scanner
        if(fXML10EntityScanner != null){ 
            fXML10EntityScanner.reset(fSymbolTable, this, fErrorReporter);
        }
        if(fXML11EntityScanner != null) {
            fXML11EntityScanner.reset(fSymbolTable, this, fErrorReporter);
        }

        // DEBUG
        if (DEBUG_ENTITIES) {
            addInternalEntity("text", "Hello, World.");
            addInternalEntity("empty-element", "<foo/>");
            addInternalEntity("balanced-element", "<foo></foo>");
            addInternalEntity("balanced-element-with-text", "<foo>Hello, World</foo>");
            addInternalEntity("balanced-element-with-entity", "<foo>&text;</foo>");
            addInternalEntity("unbalanced-entity", "<foo>");
            addInternalEntity("recursive-entity", "<foo>&recursive-entity2;</foo>");
            addInternalEntity("recursive-entity2", "<bar>&recursive-entity3;</bar>");
            addInternalEntity("recursive-entity3", "<baz>&recursive-entity;</baz>");
            try {
                addExternalEntity("external-text", null, "external-text.ent", "test/external-text.xml");
                addExternalEntity("external-balanced-element", null, "external-balanced-element.ent", "test/external-balanced-element.xml");
                addExternalEntity("one", null, "ent/one.ent", "test/external-entity.xml");
                addExternalEntity("two", null, "ent/two.ent", "test/ent/one.xml");
            }
            catch (IOException ex) {
                // should never happen
            }
        }

        // copy declared entities
        if (fDeclaredEntities != null) {
            Iterator entries = fDeclaredEntities.entrySet().iterator();
            while (entries.hasNext()) {
                Map.Entry entry = (Map.Entry) entries.next();
                Object key = entry.getKey();
                Object value = entry.getValue();
                fEntities.put(key, value);
            }
        }
        fEntityHandler = null;

    } // reset(XMLComponentManager)

    
Returns a list of feature identifiers that are recognized by
this component. This method may return null if no features
are recognized by this component.
/**
     * Returns a list of feature identifiers that are recognized by
     * this component. This method may return null if no features
     * are recognized by this component.
     */
    public String[] getRecognizedFeatures() {
        return (String[])(RECOGNIZED_FEATURES.clone());
    } // getRecognizedFeatures():String[]

    
Sets the state of a feature. This method is called by the component
manager any time after reset when a feature changes state.

Note: Components should silently ignore features
that do not affect the operation of the component.
Params:
featureId – The feature identifier.
state –     The state of the feature.
Throws:
SAXNotRecognizedException – The component should not throw
                                  this exception.
SAXNotSupportedException – The component should not throw
                                 this exception./**
     * Sets the state of a feature. This method is called by the component
     * manager any time after reset when a feature changes state.
     * <p>
     * <strong>Note:</strong> Components should silently ignore features
     * that do not affect the operation of the component.
     *
     * @param featureId The feature identifier.
     * @param state     The state of the feature.
     *
     * @throws SAXNotRecognizedException The component should not throw
     *                                   this exception.
     * @throws SAXNotSupportedException The component should not throw
     *                                  this exception.
     */
    public void setFeature(String featureId, boolean state)
        throws XMLConfigurationException {

        // xerces features
        if (featureId.startsWith(Constants.XERCES_FEATURE_PREFIX)) {
            final int suffixLength = featureId.length() - Constants.XERCES_FEATURE_PREFIX.length();
            if (suffixLength == Constants.ALLOW_JAVA_ENCODINGS_FEATURE.length() && 
                featureId.endsWith(Constants.ALLOW_JAVA_ENCODINGS_FEATURE)) {
                fAllowJavaEncodings = state;
            }
        }

    } // setFeature(String,boolean)

    
Returns a list of property identifiers that are recognized by
this component. This method may return null if no properties
are recognized by this component.
/**
     * Returns a list of property identifiers that are recognized by
     * this component. This method may return null if no properties
     * are recognized by this component.
     */
    public String[] getRecognizedProperties() {
        return (String[])(RECOGNIZED_PROPERTIES.clone());
    } // getRecognizedProperties():String[]

    
Sets the value of a property. This method is called by the component
manager any time after reset when a property changes value.

Note: Components should silently ignore properties
that do not affect the operation of the component.
Params:
propertyId – The property identifier.
value –      The value of the property.
Throws:
SAXNotRecognizedException – The component should not throw
                                  this exception.
SAXNotSupportedException – The component should not throw
                                 this exception./**
     * Sets the value of a property. This method is called by the component
     * manager any time after reset when a property changes value.
     * <p>
     * <strong>Note:</strong> Components should silently ignore properties
     * that do not affect the operation of the component.
     *
     * @param propertyId The property identifier.
     * @param value      The value of the property.
     *
     * @throws SAXNotRecognizedException The component should not throw
     *                                   this exception.
     * @throws SAXNotSupportedException The component should not throw
     *                                  this exception.
     */
    public void setProperty(String propertyId, Object value)
        throws XMLConfigurationException {

        // Xerces properties
        if (propertyId.startsWith(Constants.XERCES_PROPERTY_PREFIX)) {
            final int suffixLength = propertyId.length() - Constants.XERCES_PROPERTY_PREFIX.length();
        	
            if (suffixLength == Constants.SYMBOL_TABLE_PROPERTY.length() && 
                propertyId.endsWith(Constants.SYMBOL_TABLE_PROPERTY)) {
                fSymbolTable = (SymbolTable)value;
                return;
            }
            if (suffixLength == Constants.ERROR_REPORTER_PROPERTY.length() && 
                propertyId.endsWith(Constants.ERROR_REPORTER_PROPERTY)) {
                fErrorReporter = (XMLErrorReporter)value;
                return;
            }
            if (suffixLength == Constants.ENTITY_RESOLVER_PROPERTY.length() && 
                propertyId.endsWith(Constants.ENTITY_RESOLVER_PROPERTY)) {
                fEntityResolver = (XMLEntityResolver)value;
                return;
            }
            if (suffixLength == Constants.BUFFER_SIZE_PROPERTY.length() && 
                propertyId.endsWith(Constants.BUFFER_SIZE_PROPERTY)) {
                Integer bufferSize = (Integer)value;
                if (bufferSize != null &&
                    bufferSize.intValue() > DEFAULT_XMLDECL_BUFFER_SIZE) {
                    fBufferSize = bufferSize.intValue();
                    fEntityScanner.setBufferSize(fBufferSize);
                    fSmallByteBufferPool.setBufferSize(fBufferSize);
                    fLargeByteBufferPool.setBufferSize(fBufferSize << 1);
                    fCharacterBufferPool.setExternalBufferSize(fBufferSize);
                }
            }
            if (suffixLength == Constants.SECURITY_MANAGER_PROPERTY.length() && 
                propertyId.endsWith(Constants.SECURITY_MANAGER_PROPERTY)) {
                fSecurityManager = (SecurityManager)value; 
                fEntityExpansionLimit = (fSecurityManager != null)?fSecurityManager.getEntityExpansionLimit():0;
            }
        }

    } // setProperty(String,Object)

    
Returns the default state for a feature, or null if this
component does not want to report a default value for this
feature.
Params:
featureId – The feature identifier.
Since:
Xerces 2.2.0/** 
     * Returns the default state for a feature, or null if this
     * component does not want to report a default value for this
     * feature.
     *
     * @param featureId The feature identifier.
     *
     * @since Xerces 2.2.0
     */
    public Boolean getFeatureDefault(String featureId) {
        for (int i = 0; i < RECOGNIZED_FEATURES.length; i++) {
            if (RECOGNIZED_FEATURES[i].equals(featureId)) {
                return FEATURE_DEFAULTS[i];
            }
        }
        return null;
    } // getFeatureDefault(String):Boolean

    
Returns the default state for a property, or null if this
component does not want to report a default value for this
property. 
Params:
propertyId – The property identifier.
Since:
Xerces 2.2.0/** 
     * Returns the default state for a property, or null if this
     * component does not want to report a default value for this
     * property. 
     *
     * @param propertyId The property identifier.
     *
     * @since Xerces 2.2.0
     */
    public Object getPropertyDefault(String propertyId) {
        for (int i = 0; i < RECOGNIZED_PROPERTIES.length; i++) {
            if (RECOGNIZED_PROPERTIES[i].equals(propertyId)) {
                return PROPERTY_DEFAULTS[i];
            }
        }
        return null;
    } // getPropertyDefault(String):Object

    //
    // Public static methods
    //

    // current value of the "user.dir" property
    private static String gUserDir;
    // cached URI object for the current value of the escaped "user.dir" property stored as a URI
    private static URI gUserDirURI;
    // which ASCII characters need to be escaped
    private static final boolean gNeedEscaping[] = new boolean[128];
    // the first hex character if a character needs to be escaped
    private static final char gAfterEscaping1[] = new char[128];
    // the second hex character if a character needs to be escaped
    private static final char gAfterEscaping2[] = new char[128];
    private static final char[] gHexChs = {'0', '1', '2', '3', '4', '5', '6', '7',
                                           '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
    // initialize the above 3 arrays
    static {
        for (int i = 0; i <= 0x1f; i++) {
            gNeedEscaping[i] = true;
            gAfterEscaping1[i] = gHexChs[i >> 4];
            gAfterEscaping2[i] = gHexChs[i & 0xf];
        }
        gNeedEscaping[0x7f] = true;
        gAfterEscaping1[0x7f] = '7';
        gAfterEscaping2[0x7f] = 'F';
        char[] escChs = {' ', '<', '>', '#', '%', '"', '{', '}',
                         '|', '\\', '^', '~', '[', ']', '`'};
        int len = escChs.length;
        char ch;
        for (int i = 0; i < len; i++) {
            ch = escChs[i];
            gNeedEscaping[ch] = true;
            gAfterEscaping1[ch] = gHexChs[ch >> 4];
            gAfterEscaping2[ch] = gHexChs[ch & 0xf];
        }
    }
    
    private static PrivilegedAction GET_USER_DIR_SYSTEM_PROPERTY = new PrivilegedAction() {
        public Object run() {
            return System.getProperty("user.dir");
        }
    };
    
    // To escape the "user.dir" system property, by using %HH to represent
    // special ASCII characters: 0x00~0x1F, 0x7F, ' ', '<', '>', '#', '%'
    // and '"'. It's a static method, so needs to be synchronized.
    // this method looks heavy, but since the system property isn't expected
    // to change often, so in most cases, we only need to return the URI
    // that was escaped before.
    // According to the URI spec, non-ASCII characters (whose value >= 128)
    // need to be escaped too.
    // REVISIT: don't know how to escape non-ASCII characters, especially
    // which encoding to use. Leave them for now.
    private static synchronized URI getUserDir() throws URI.MalformedURIException {
        // get the user.dir property
        String userDir = "";
        try {
            userDir = (String) AccessController.doPrivileged(GET_USER_DIR_SYSTEM_PROPERTY);
        }
        catch (SecurityException se) {}

        // return empty string if property value is empty string.
        if (userDir.length() == 0) 
            return new URI("file", "", "", null, null);
        
        // compute the new escaped value if the new property value doesn't
        // match the previous one
        if (gUserDirURI != null && userDir.equals(gUserDir)) {
            return gUserDirURI;
        }

        // record the new value as the global property value
        gUserDir = userDir;

        char separator = java.io.File.separatorChar;
        userDir = userDir.replace(separator, '/');

        int len = userDir.length(), ch;
        StringBuffer buffer = new StringBuffer(len*3);
        // change C:/blah to /C:/blah
        if (len >= 2 && userDir.charAt(1) == ':') {
            ch = Character.toUpperCase(userDir.charAt(0));
            if (ch >= 'A' && ch <= 'Z') {
                buffer.append('/');
            }
        }

        // for each character in the path
        int i = 0;
        for (; i < len; i++) {
            ch = userDir.charAt(i);
            // if it's not an ASCII character, break here, and use UTF-8 encoding
            if (ch >= 128)
                break;
            if (gNeedEscaping[ch]) {
                buffer.append('%');
                buffer.append(gAfterEscaping1[ch]);
                buffer.append(gAfterEscaping2[ch]);
                // record the fact that it's escaped
            }
            else {
                buffer.append((char)ch);
            }
        }

        // we saw some non-ascii character
        if (i < len) {
            // get UTF-8 bytes for the remaining sub-string
            byte[] bytes = null;
            byte b;
            try {
                bytes = userDir.substring(i).getBytes("UTF-8");
            } catch (java.io.UnsupportedEncodingException e) {
                // should never happen
                return new URI("file", "", userDir, null, null);
            }
            len = bytes.length;

            // for each byte
            for (i = 0; i < len; i++) {
                b = bytes[i];
                // for non-ascii character: make it positive, then escape
                if (b < 0) {
                    ch = b + 256;
                    buffer.append('%');
                    buffer.append(gHexChs[ch >> 4]);
                    buffer.append(gHexChs[ch & 0xf]);
                }
                else if (gNeedEscaping[b]) {
                    buffer.append('%');
                    buffer.append(gAfterEscaping1[b]);
                    buffer.append(gAfterEscaping2[b]);
                }
                else {
                    buffer.append((char)b);
                }
            }
        }

        // change blah/blah to blah/blah/
        if (!userDir.endsWith("/"))
            buffer.append('/');
        
        gUserDirURI = new URI("file", "", buffer.toString(), null, null);

        return gUserDirURI;
    }
    
    
Absolutizes a URI using the current value
of the "user.dir" property as the base URI. If
the URI is already absolute, this is a no-op.
Params:
uri – the URI to absolutize/**
     * Absolutizes a URI using the current value
     * of the "user.dir" property as the base URI. If
     * the URI is already absolute, this is a no-op.
     * 
     * @param uri the URI to absolutize
     */
    public static void absolutizeAgainstUserDir(URI uri) 
        throws URI.MalformedURIException {
        uri.absolutize(getUserDir());
    }

    
Expands a system id and returns the system id as a URI, if
it can be expanded. A return value of null means that the
identifier is already expanded. An exception thrown
indicates a failure to expand the id.
Params:
systemId – The systemId to be expanded.
Returns:
Returns the URI string representing the expanded system
        identifier. A null value indicates that the given
        system identifier is already expanded./**
     * Expands a system id and returns the system id as a URI, if
     * it can be expanded. A return value of null means that the
     * identifier is already expanded. An exception thrown
     * indicates a failure to expand the id.
     *
     * @param systemId The systemId to be expanded.
     *
     * @return Returns the URI string representing the expanded system
     *         identifier. A null value indicates that the given
     *         system identifier is already expanded.
     *
     */
    public static String expandSystemId(String systemId, String baseSystemId,
                                        boolean strict)
            throws URI.MalformedURIException {

        // check if there is a system id before 
        // trying to expand it.
        if (systemId == null) {
            return null;
        }
        
        // system id has to be a valid URI
        if (strict) {
            return expandSystemIdStrictOn(systemId, baseSystemId);
        }

        // Assume the URIs are well-formed. If it turns out they're not, try fixing them up.
        try {
            return expandSystemIdStrictOff(systemId, baseSystemId);
        }
        catch (URI.MalformedURIException e) {
            // continue on...
        }
        
        // check for bad parameters id
        if (systemId.length() == 0) {
            return systemId;
        }
        
        // normalize id
        String id = fixURI(systemId);

        // normalize base
        URI base = null;
        URI uri = null;
        try {
            if (baseSystemId == null || baseSystemId.length() == 0 ||
                baseSystemId.equals(systemId)) {
                base = getUserDir();
            }
            else {
                try {
                    base = new URI(fixURI(baseSystemId).trim());
                }
                catch (URI.MalformedURIException e) {
                    if (baseSystemId.indexOf(':') != -1) {
                        // for xml schemas we might have baseURI with
                        // a specified drive
                        base = new URI("file", "", fixURI(baseSystemId).trim(), null, null);
                    }
                    else {
                        base = new URI(getUserDir(), fixURI(baseSystemId));
                    }
                }
             }
             // expand id
             uri = new URI(base, id.trim());
        }
        catch (Exception e) {
            // let it go through

        }

        if (uri == null) {
            return systemId;
        }
        return uri.toString();

    } // expandSystemId(String,String,boolean):String
    
    
Helper method for expandSystemId(String,String,boolean):String
/**
     * Helper method for expandSystemId(String,String,boolean):String
     */
    private static String expandSystemIdStrictOn(String systemId, String baseSystemId)
        throws URI.MalformedURIException {
        
        URI systemURI = new URI(systemId, true);
        // If it's already an absolute one, return it
        if (systemURI.isAbsoluteURI()) {
            return systemId;
        }
        
        // If there isn't a base URI, use the working directory
        URI baseURI = null;
        if (baseSystemId == null || baseSystemId.length() == 0) {
            baseURI = getUserDir();
        }
        else {
            baseURI = new URI(baseSystemId, true);
            if (!baseURI.isAbsoluteURI()) {
                // assume "base" is also a relative uri
                baseURI.absolutize(getUserDir());
            }
        }
        
        // absolutize the system identifier using the base URI
        systemURI.absolutize(baseURI);
        
        // return the string rep of the new uri (an absolute one)
        return systemURI.toString();
        
        // if any exception is thrown, it'll get thrown to the caller.
        
    } // expandSystemIdStrictOn(String,String):String
    
    
Helper method for expandSystemId(String,String,boolean):String
/**
     * Helper method for expandSystemId(String,String,boolean):String
     */
    private static String expandSystemIdStrictOff(String systemId, String baseSystemId)
        throws URI.MalformedURIException {
        
        URI systemURI = new URI(systemId, true);
        // If it's already an absolute one, return it
        if (systemURI.isAbsoluteURI()) {
            if (systemURI.getScheme().length() > 1) {
                return systemId;
            }
            /** 
             * If the scheme's length is only one character,
             * it's likely that this was intended as a file
             * path. Fixing this up in expandSystemId to
             * maintain backwards compatibility.
             */
            throw new URI.MalformedURIException();
        }
        
        // If there isn't a base URI, use the working directory
        URI baseURI = null;
        if (baseSystemId == null || baseSystemId.length() == 0) {
            baseURI = getUserDir();
        }
        else {
            baseURI = new URI(baseSystemId, true);
            if (!baseURI.isAbsoluteURI()) {
                // assume "base" is also a relative uri
                baseURI.absolutize(getUserDir());
            }
        }
        
        // absolutize the system identifier using the base URI
        systemURI.absolutize(baseURI);
        
        // return the string rep of the new uri (an absolute one)
        return systemURI.toString();
        
        // if any exception is thrown, it'll get thrown to the caller.
        
    } // expandSystemIdStrictOff(String,String):String
    
    public static OutputStream createOutputStream(String uri) throws IOException {
        // URI was specified. Handle relative URIs.
        final String expanded = XMLEntityManager.expandSystemId(uri, null, true);
        final URL url = new URL(expanded != null ? expanded : uri);
        OutputStream out = null;
        String protocol = url.getProtocol();
        String host = url.getHost();
        // Use FileOutputStream if this URI is for a local file.
        if (protocol.equals("file") 
                && (host == null || host.length() == 0 || host.equals("localhost"))) {
            File file = new File(getPathWithoutEscapes(url.getPath()));
            if (!file.exists()) {
                File parent = file.getParentFile();
                if (parent != null && !parent.exists()) {
                    parent.mkdirs();
                }
            }
            out = new FileOutputStream(file);
        }
        // Try to write to some other kind of URI. Some protocols
        // won't support this, though HTTP should work.
        else {
            URLConnection urlCon = url.openConnection();
            urlCon.setDoInput(false);
            urlCon.setDoOutput(true);
            urlCon.setUseCaches(false); // Enable tunneling.
            if (urlCon instanceof HttpURLConnection) {
                // The DOM L3 REC says if we are writing to an HTTP URI
                // it is to be done with an HTTP PUT.
                HttpURLConnection httpCon = (HttpURLConnection) urlCon;
                httpCon.setRequestMethod("PUT");
            }
            out = urlCon.getOutputStream();
        }
        return out;
    }
    
    private static String getPathWithoutEscapes(String origPath) {
        if (origPath != null && origPath.length() != 0 && origPath.indexOf('%') != -1) {
            // Locate the escape characters
            StringTokenizer tokenizer = new StringTokenizer(origPath, "%");
            StringBuffer result = new StringBuffer(origPath.length());
            int size = tokenizer.countTokens();
            result.append(tokenizer.nextToken());
            for(int i = 1; i < size; ++i) {
                String token = tokenizer.nextToken();
                // Decode the 2 digit hexadecimal number following % in '%nn'
                result.append((char)Integer.valueOf(token.substring(0, 2), 16).intValue());
                result.append(token.substring(2));
            }
            return result.toString();
        }
        return origPath;
    }

    //
    // Protected methods
    //

    
Ends an entity.
Throws:
XNIException – Thrown by entity handler to signal an error./**
     * Ends an entity.
     *
     * @throws XNIException Thrown by entity handler to signal an error.
     */
    void endEntity() throws XNIException {

        // call handler
        if (DEBUG_BUFFER) {
            System.out.print("(endEntity: ");
            print(fCurrentEntity);
            System.out.println();
        }
        if (fEntityHandler != null) {
            fEntityHandler.endEntity(fCurrentEntity.name, null);
        }
        
        // Close the reader for the current entity once we're 
        // done with it, and remove it from our stack. If parsing
        // is halted at some point, the rest of the readers on
        // the stack will be closed during cleanup.
        try {
            fCurrentEntity.reader.close();
        }
        catch (IOException e) {
            // ignore
        }
        // REVISIT: We should never encounter underflow if the calls
        // to startEntity and endEntity are balanced, but guard
        // against the EmptyStackException for now. -- mrglavas
        if (!fReaderStack.isEmpty()) {
            fReaderStack.pop();
        } 

        // Release the character buffer back to the pool for reuse
        fCharacterBufferPool.returnBuffer(fCurrentEntity.fCharacterBuffer);
        
        // Release the byte buffer back to the pool for reuse
        if (fCurrentEntity.fByteBuffer != null) {
            if (fCurrentEntity.fByteBuffer.length == fBufferSize) {
                fSmallByteBufferPool.returnBuffer(fCurrentEntity.fByteBuffer);
            }
            else {
                fLargeByteBufferPool.returnBuffer(fCurrentEntity.fByteBuffer);
            }
        }
        
        // Pop entity stack.
        fCurrentEntity = fEntityStack.size() > 0
                       ? (ScannedEntity)fEntityStack.pop() : null;
        fEntityScanner.setCurrentEntity(fCurrentEntity);
        if (DEBUG_BUFFER) {
            System.out.print(")endEntity: ");
            print(fCurrentEntity);
            System.out.println();
        }

    } // endEntity()
    
    
Returns the IANA encoding name that is auto-detected from
the bytes specified, with the endian-ness of that encoding where appropriate.
Params:
b4 –    The first four bytes of the input.
count – The number of bytes actually read.
Returns:
an instance of EncodingInfo which represents the auto-detected encoding./**
     * Returns the IANA encoding name that is auto-detected from
     * the bytes specified, with the endian-ness of that encoding where appropriate.
     *
     * @param b4    The first four bytes of the input.
     * @param count The number of bytes actually read.
     * @return an instance of EncodingInfo which represents the auto-detected encoding.
     */
    protected EncodingInfo getEncodingInfo(byte[] b4, int count) {

        if (count < 2) {
            return EncodingInfo.UTF_8;
        }

        // UTF-16, with BOM
        int b0 = b4[0] & 0xFF;
        int b1 = b4[1] & 0xFF;
        if (b0 == 0xFE && b1 == 0xFF) {
            // UTF-16, big-endian
            return EncodingInfo.UTF_16_BIG_ENDIAN_WITH_BOM;
        }
        if (b0 == 0xFF && b1 == 0xFE) {
            // UTF-16, little-endian
            return EncodingInfo.UTF_16_LITTLE_ENDIAN_WITH_BOM;
        }

        // default to UTF-8 if we don't have enough bytes to make a
        // good determination of the encoding
        if (count < 3) {
            return EncodingInfo.UTF_8;
        }

        // UTF-8 with a BOM
        int b2 = b4[2] & 0xFF;
        if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) {
            return EncodingInfo.UTF_8_WITH_BOM;
        }

        // default to UTF-8 if we don't have enough bytes to make a
        // good determination of the encoding
        if (count < 4) {
            return EncodingInfo.UTF_8;
        }

        // other encodings
        int b3 = b4[3] & 0xFF;
        if (b0 == 0x00 && b1 == 0x00 && b2 == 0x00 && b3 == 0x3C) {
            // UCS-4, big endian (1234)
            return EncodingInfo.UCS_4_BIG_ENDIAN;
        }
        if (b0 == 0x3C && b1 == 0x00 && b2 == 0x00 && b3 == 0x00) {
            // UCS-4, little endian (4321)
            return EncodingInfo.UCS_4_LITTLE_ENDIAN;
        }
        if (b0 == 0x00 && b1 == 0x00 && b2 == 0x3C && b3 == 0x00) {
            // UCS-4, unusual octet order (2143)
            // REVISIT: What should this be?
            return EncodingInfo.UCS_4_UNUSUAL_BYTE_ORDER;
        }
        if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x00) {
            // UCS-4, unusual octect order (3412)
            // REVISIT: What should this be?
            return EncodingInfo.UCS_4_UNUSUAL_BYTE_ORDER;
        }
        if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F) {
            // UTF-16, big-endian, no BOM
            // (or could turn out to be UCS-2...
            // REVISIT: What should this be?
            return EncodingInfo.UTF_16_BIG_ENDIAN;
        }
        if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00) {
            // UTF-16, little-endian, no BOM
            // (or could turn out to be UCS-2...
            return EncodingInfo.UTF_16_LITTLE_ENDIAN;
        }
        if (b0 == 0x4C && b1 == 0x6F && b2 == 0xA7 && b3 == 0x94) {
            // EBCDIC
            // a la xerces1, return CP037 instead of EBCDIC here
            return EncodingInfo.EBCDIC;
        }

        // default encoding
        return EncodingInfo.UTF_8;

    } // getEncodingName(byte[],int):Object[]

    
Creates a reader capable of reading the given input stream in
the specified encoding.
Params:
inputStream –  The input stream.
encoding –     The encoding name that the input stream is
                    encoded using. If the user has specified that
                    Java encoding names are allowed, then the
                    encoding name may be a Java encoding name;
                    otherwise, it is an ianaEncoding name.
isBigEndian –   For encodings (like uCS-4), whose names cannot
                     specify a byte order, this tells whether the order is bigEndian. Null means
                     unknown or not relevant.
Returns:
Returns a reader./**
     * Creates a reader capable of reading the given input stream in
     * the specified encoding.
     *
     * @param inputStream  The input stream.
     * @param encoding     The encoding name that the input stream is
     *                     encoded using. If the user has specified that
     *                     Java encoding names are allowed, then the
     *                     encoding name may be a Java encoding name;
     *                     otherwise, it is an ianaEncoding name.
     * @param isBigEndian   For encodings (like uCS-4), whose names cannot
     *                      specify a byte order, this tells whether the order is bigEndian. Null means
     *                      unknown or not relevant.
     *
     * @return Returns a reader.
     */
    protected Reader createReader(InputStream inputStream, String encoding, Boolean isBigEndian)
        throws IOException {

        // if the encoding is UTF-8 use the optimized UTF-8 reader
        if (encoding == "UTF-8" || encoding == null) {
            return createUTF8Reader(inputStream);
        }
        
        // If the encoding is UTF-16 use the optimized UTF-16 reader
        if (encoding == "UTF-16" && isBigEndian != null) {
            return createUTF16Reader(inputStream, isBigEndian.booleanValue());
        }

        // try to use an optimized reader
        String ENCODING = encoding.toUpperCase(Locale.ENGLISH);
        if (ENCODING.equals("UTF-8")) {
            return createUTF8Reader(inputStream);
        }
        if (ENCODING.equals("UTF-16BE")) {
            return createUTF16Reader(inputStream, true);
        }
        if (ENCODING.equals("UTF-16LE")) {
            return createUTF16Reader(inputStream, false);
        }
        if (ENCODING.equals("ISO-10646-UCS-4")) {
            if(isBigEndian != null) {
                boolean isBE = isBigEndian.booleanValue();
                if(isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS4BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS4LE);
                }
            } else {
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                       "EncodingByteOrderUnsupported",
                                       new Object[] { encoding },
                                       XMLErrorReporter.SEVERITY_FATAL_ERROR);
            }
        }
        if (ENCODING.equals("ISO-10646-UCS-2")) {
            if(isBigEndian != null) { // should never happen with this encoding...
                boolean isBE = isBigEndian.booleanValue();
                if(isBE) {
                    return new UCSReader(inputStream, UCSReader.UCS2BE);
                } else {
                    return new UCSReader(inputStream, UCSReader.UCS2LE);
                }
            } else {
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                       "EncodingByteOrderUnsupported",
                                       new Object[] { encoding },
                                       XMLErrorReporter.SEVERITY_FATAL_ERROR);
            }
        }

        // check for valid name
        boolean validIANA = XMLChar.isValidIANAEncoding(encoding);
        boolean validJava = XMLChar.isValidJavaEncoding(encoding);
        if (!validIANA || (fAllowJavaEncodings && !validJava)) {
            fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                       "EncodingDeclInvalid",
                                       new Object[] { encoding },
                                       XMLErrorReporter.SEVERITY_FATAL_ERROR);
            // NOTE: AndyH suggested that, on failure, we use ISO Latin 1
            //       because every byte is a valid ISO Latin 1 character.
            //       It may not translate correctly but if we failed on
            //       the encoding anyway, then we're expecting the content
            //       of the document to be bad. This will just prevent an
            //       invalid UTF-8 sequence to be detected. This is only
            //       important when continue-after-fatal-error is turned
            //       on. -Ac
            return createLatin1Reader(inputStream);
        }

        // try to use a Java reader
        String javaEncoding = EncodingMap.getIANA2JavaMapping(ENCODING);
        if (javaEncoding == null) {
            if (fAllowJavaEncodings) {
                javaEncoding = encoding;
            } 
            else {
                fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                       "EncodingDeclInvalid",
                                       new Object[] { encoding },
                                       XMLErrorReporter.SEVERITY_FATAL_ERROR);
                // see comment above.
                return createLatin1Reader(inputStream);
            }
        }
        else if (javaEncoding.equals("ASCII")) {
            return createASCIIReader(inputStream);
        }
        else if (javaEncoding.equals("ISO8859_1")) {
            return createLatin1Reader(inputStream);
        }
        if (DEBUG_ENCODINGS) {
            System.out.print("$$$ creating Java InputStreamReader: encoding="+javaEncoding);
            if (javaEncoding == encoding) {
                System.out.print(" (IANA encoding)");
            }
            System.out.println();
        }
        return new InputStreamReader(inputStream, javaEncoding);

    } // createReader(InputStream,String, Boolean): Reader
    
    
Create a new UTF-8 reader from the InputStream. /** Create a new UTF-8 reader from the InputStream. **/
    private Reader createUTF8Reader(InputStream stream) {
        if (DEBUG_ENCODINGS) {
            System.out.println("$$$ creating UTF8Reader");
        }
        if (fTempByteBuffer == null) {
            fTempByteBuffer = fSmallByteBufferPool.getBuffer();
        }
        return new UTF8Reader(stream,
                fTempByteBuffer, 
                fErrorReporter.getMessageFormatter(XMLMessageFormatter.XML_DOMAIN), 
                fErrorReporter.getLocale());
    } // createUTF8Reader(InputStream):Reader
    
    
Create a new UTF-16 reader from the InputStream. /** Create a new UTF-16 reader from the InputStream. **/
    private Reader createUTF16Reader(InputStream stream, boolean isBigEndian) {
        if (DEBUG_ENCODINGS) {
            System.out.println("$$$ creating UTF16Reader");
        }
        if (fTempByteBuffer == null) {
            fTempByteBuffer = fLargeByteBufferPool.getBuffer();
        }
        // The cached buffer is too small, we need a larger one.
        else if (fTempByteBuffer.length == fBufferSize) {
            fSmallByteBufferPool.returnBuffer(fTempByteBuffer);
            fTempByteBuffer = fLargeByteBufferPool.getBuffer();
        }
        return new UTF16Reader(stream,
                fTempByteBuffer, 
                isBigEndian, 
                fErrorReporter.getMessageFormatter(XMLMessageFormatter.XML_DOMAIN), 
                fErrorReporter.getLocale());
    } // createUTF16Reader(InputStream):Reader
    
    
Create a new ASCII reader from the InputStream. /** Create a new ASCII reader from the InputStream. **/
    private Reader createASCIIReader(InputStream stream) {
        if (DEBUG_ENCODINGS) {
            System.out.println("$$$ creating ASCIIReader");
        }
        if (fTempByteBuffer == null) {
            fTempByteBuffer = fSmallByteBufferPool.getBuffer();
        }
        return new ASCIIReader(stream, 
                fTempByteBuffer, 
                fErrorReporter.getMessageFormatter(XMLMessageFormatter.XML_DOMAIN), 
                fErrorReporter.getLocale());
    } // createASCIIReader(InputStream):Reader
    
    
Create a new ISO-8859-1 reader from the InputStream. /** Create a new ISO-8859-1 reader from the InputStream. **/
    private Reader createLatin1Reader(InputStream stream) {
        if (DEBUG_ENCODINGS) {
            System.out.println("$$$ creating Latin1Reader");
        }
        if (fTempByteBuffer == null) {
            fTempByteBuffer = fSmallByteBufferPool.getBuffer();
        }
        return new Latin1Reader(stream, fTempByteBuffer);
    } // createLatin1Reader(InputStream):Reader

    //
    // Protected static methods
    //

    
Fixes a platform dependent filename to standard URI form.
Params:
str – The string to fix.
Returns:
Returns the fixed URI string./**
     * Fixes a platform dependent filename to standard URI form.
     *
     * @param str The string to fix.
     *
     * @return Returns the fixed URI string.
     */
    protected static String fixURI(String str) {

        // handle platform dependent strings
        str = str.replace(java.io.File.separatorChar, '/');

        StringBuffer sb = null;

        // Windows fix
        if (str.length() >= 2) {
            char ch1 = str.charAt(1);
            // change "C:blah" to "file:///C:blah"
            if (ch1 == ':') {
                char ch0 = Character.toUpperCase(str.charAt(0));
                if (ch0 >= 'A' && ch0 <= 'Z') {
                    sb = new StringBuffer(str.length() + 8);
                    sb.append("file:///");
                }
            }
            // change "//blah" to "file://blah"
            else if (ch1 == '/' && str.charAt(0) == '/') {
                sb = new StringBuffer(str.length() + 5);
                sb.append("file:");
            }
        }

        int pos = str.indexOf(' ');
        // there is no space in the string
        // we just append "str" to the end of sb
        if (pos < 0) {
            if (sb != null) {
                sb.append(str);
                str = sb.toString();
            }
        }
        // otherwise, convert all ' ' to "%20".
        // Note: the following algorithm might not be very performant,
        // but people who want to use invalid URI's have to pay the price.
        else {
            if (sb == null)
                sb = new StringBuffer(str.length());
            // put characters before ' ' into the string buffer
            for (int i = 0; i < pos; i++)
                sb.append(str.charAt(i));
            // and %20 for the space
            sb.append("%20");
            // for the remamining part, also convert ' ' to "%20".
            for (int i = pos+1; i < str.length(); i++) {
                if (str.charAt(i) == ' ')
                    sb.append("%20");
                else
                    sb.append(str.charAt(i));
            }
            str = sb.toString();
        }

        // done
        return str;

    } // fixURI(String):String

    //
    // Package visible methods
    //

    
Returns the hashtable of declared entities.

REVISIT:
This should be done the "right" way by designing a better way to
enumerate the declared entities. For now, this method is needed
by the constructor that takes an XMLEntityManager parameter.
/**
     * Returns the hashtable of declared entities.
     * <p>
     * <strong>REVISIT:</strong>
     * This should be done the "right" way by designing a better way to
     * enumerate the declared entities. For now, this method is needed
     * by the constructor that takes an XMLEntityManager parameter.
     */
    Hashtable getDeclaredEntities() {
        return fEntities;
    } // getDeclaredEntities():Hashtable

    
Prints the contents of the buffer. /** Prints the contents of the buffer. */
    static final void print(ScannedEntity currentEntity) {
        if (DEBUG_BUFFER) {
            if (currentEntity != null) {
                System.out.print('[');
                System.out.print(currentEntity.count);
                System.out.print(' ');
                System.out.print(currentEntity.position);
                if (currentEntity.count > 0) {
                    System.out.print(" \"");
                    for (int i = 0; i < currentEntity.count; i++) {
                        if (i == currentEntity.position) {
                            System.out.print('^');
                        }
                        char c = currentEntity.ch[i];
                        switch (c) {
                            case '\n': {
                                System.out.print("\\n");
                                break;
                            }
                            case '\r': {
                                System.out.print("\\r");
                                break;
                            }
                            case '\t': {
                                System.out.print("\\t");
                                break;
                            }
                            case '\\': {
                                System.out.print("\\\\");
                                break;
                            }
                            default: {
                                System.out.print(c);
                            }
                        }
                    }
                    if (currentEntity.position == currentEntity.count) {
                        System.out.print('^');
                    }
                    System.out.print('"');
                }
                System.out.print(']');
                System.out.print(" @ ");
                System.out.print(currentEntity.lineNumber);
                System.out.print(',');
                System.out.print(currentEntity.columnNumber);
            }
            else {
                System.out.print("*NO CURRENT ENTITY*");
            }
        }
    } // print(ScannedEntity)

    //
    // Classes
    //

    
Entity information.
Author:
Andy Clark, IBM
@xerces.internal
/**
     * Entity information.
     * 
     * @xerces.internal

     *
     * @author Andy Clark, IBM
     */
    public static abstract class Entity {

        //
        // Data
        //

        
Entity name. /** Entity name. */
        public String name;

        // whether this entity's declaration was found in the internal
        // or external subset
        public boolean inExternalSubset; 

        //
        // Constructors
        //

        
Default constructor. /** Default constructor. */
        public Entity() {
            clear();
        } // <init>()

        
Constructs an entity. /** Constructs an entity. */
        public Entity(String name, boolean inExternalSubset) {
            this.name = name;
            this.inExternalSubset = inExternalSubset;
        } // <init>(String)

        //
        // Public methods
        //

        
Returns true if this entity was declared in the external subset. /** Returns true if this entity was declared in the external subset. */
        public boolean isEntityDeclInExternalSubset () {
            return inExternalSubset;
        } 

        
Returns true if this is an external entity. /** Returns true if this is an external entity. */
        public abstract boolean isExternal();

        
Returns true if this is an unparsed entity. /** Returns true if this is an unparsed entity. */
        public abstract boolean isUnparsed();

        
Clears the entity. /** Clears the entity. */
        public void clear() {
            name = null;
            inExternalSubset = false;
        } // clear()

        
Sets the values of the entity. /** Sets the values of the entity. */
        public void setValues(Entity entity) {
            name = entity.name;
            inExternalSubset = entity.inExternalSubset;
        } // setValues(Entity)

    } // class Entity

    
Internal entity.
Author:
Andy Clark, IBM
@xerces.internal
/**
     * Internal entity.
     * 
     * @xerces.internal

     *
     * @author Andy Clark, IBM
     */
    protected static class InternalEntity
        extends Entity {

        //
        // Data
        //

        
Text value of entity. /** Text value of entity. */
        public String text;
        
        
Count of direct and indirect references to parameter entities in the value of the entity. /** Count of direct and indirect references to parameter entities in the value of the entity. */
        public int paramEntityRefs;

        //
        // Constructors
        //

        
Default constructor. /** Default constructor. */
        public InternalEntity() {
            clear();
        } // <init>()

        
Constructs an internal entity. /** Constructs an internal entity. */
        public InternalEntity(String name, String text, boolean inExternalSubset) {
            super(name,inExternalSubset);
            this.text = text;
        } // <init>(String,String)
        
        
Constructs an internal entity. /** Constructs an internal entity. */
        public InternalEntity(String name, String text, boolean inExternalSubset, int paramEntityRefs) {
            this(name, text, inExternalSubset);
            this.paramEntityRefs = paramEntityRefs;
        } // <init>(String,String,int)

        //
        // Entity methods
        //

        
Returns true if this is an external entity. /** Returns true if this is an external entity. */
        public final boolean isExternal() {
            return false;
        } // isExternal():boolean

        
Returns true if this is an unparsed entity. /** Returns true if this is an unparsed entity. */
        public final boolean isUnparsed() {
            return false;
        } // isUnparsed():boolean

        
Clears the entity. /** Clears the entity. */
        public void clear() {
            super.clear();
            text = null;
        } // clear()

        
Sets the values of the entity. /** Sets the values of the entity. */
        public void setValues(Entity entity) {
            super.setValues(entity);
            text = null;
        } // setValues(Entity)

        
Sets the values of the entity. /** Sets the values of the entity. */
        public void setValues(InternalEntity entity) {
            super.setValues(entity);
            text = entity.text;
        } // setValues(InternalEntity)

    } // class InternalEntity

    
External entity.
Author:
Andy Clark, IBM
@xerces.internal
/**
     * External entity.
     * 
     * @xerces.internal

     *
     * @author Andy Clark, IBM
     */
    protected static class ExternalEntity
        extends Entity {

        //
        // Data
        //

        
container for all relevant entity location information. /** container for all relevant entity location information. */
        public XMLResourceIdentifier entityLocation;

        
Notation name for unparsed entity. /** Notation name for unparsed entity. */
        public String notation;

        //
        // Constructors
        //

        
Default constructor. /** Default constructor. */
        public ExternalEntity() {
            clear();
        } // <init>()

        
Constructs an internal entity. /** Constructs an internal entity. */
        public ExternalEntity(String name, XMLResourceIdentifier entityLocation,
                              String notation, boolean inExternalSubset) {
            super(name,inExternalSubset);
            this.entityLocation = entityLocation;
            this.notation = notation;
        } // <init>(String,XMLResourceIdentifier, String)

        //
        // Entity methods
        //

        
Returns true if this is an external entity. /** Returns true if this is an external entity. */
        public final boolean isExternal() {
            return true;
        } // isExternal():boolean

        
Returns true if this is an unparsed entity. /** Returns true if this is an unparsed entity. */
        public final boolean isUnparsed() {
            return notation != null;
        } // isUnparsed():boolean

        
Clears the entity. /** Clears the entity. */
        public void clear() {
            super.clear();
            entityLocation = null;
            notation = null;
        } // clear()

        
Sets the values of the entity. /** Sets the values of the entity. */
        public void setValues(Entity entity) {
            super.setValues(entity);
            entityLocation = null;
            notation = null;
        } // setValues(Entity)

        
Sets the values of the entity. /** Sets the values of the entity. */
        public void setValues(ExternalEntity entity) {
            super.setValues(entity);
            entityLocation = entity.entityLocation;
            notation = entity.notation;
        } // setValues(ExternalEntity)

    } // class ExternalEntity

    
Entity state.
Author:
Andy Clark, IBM
@xerces.internal
/**
     * Entity state.
     * 
     * @xerces.internal

     *
     * @author Andy Clark, IBM
     */
    public class ScannedEntity
        extends Entity {

        //
        // Data
        //

        // i/o

        
Input stream. /** Input stream. */
        public InputStream stream;

        
Reader. /** Reader. */
        public Reader reader;

        // locator information

        
entity location information /** entity location information */
        public XMLResourceIdentifier entityLocation;

        
Line number. /** Line number. */
        public int lineNumber = 1;

        
Column number. /** Column number. */
        public int columnNumber = 1;

        // encoding
        
        
Auto-detected encoding. /** Auto-detected encoding. */
        public String encoding;
        
        
Encoding has been set externally, for example
using a SAX InputSource or a DOM LSInput.
/** 
         * Encoding has been set externally, for example
         * using a SAX InputSource or a DOM LSInput.
         */
        boolean externallySpecifiedEncoding = false;
        
        // version
        
        
XML version. /** XML version. **/
        public String xmlVersion = "1.0";
        
		// status

        
True if in a literal.  /** True if in a literal.  */
        public boolean literal;

        // whether this is an external or internal scanned entity
        public boolean isExternal;

        // buffer

        
Character buffer. /** Character buffer. */
        public char[] ch = null;
        
        
Position in character buffer. /** Position in character buffer. */
        public int position;
        
        
Base character offset for computing absolute character offset. /** Base character offset for computing absolute character offset. */
        public int baseCharOffset;
        
        
Start position in character buffer. /** Start position in character buffer. */
        public int startPosition;
        
        
Count of characters in buffer. /** Count of characters in buffer. */
        public int count;

        // to allow the reader/inputStream to behave efficiently:
        public boolean mayReadChunks;
        
        
Character buffer container. /** Character buffer container. */
        private CharacterBuffer fCharacterBuffer;
        
        
Byte buffer. /** Byte buffer. */
        private byte [] fByteBuffer;
        
        //
        // Constructors
        //

        
Constructs a scanned entity. /** Constructs a scanned entity. */
        public ScannedEntity(String name,
                             XMLResourceIdentifier entityLocation,
                             InputStream stream, Reader reader, byte [] byteBuffer,
                             String encoding, boolean literal, boolean mayReadChunks, boolean isExternal) {
            super(name,XMLEntityManager.this.fInExternalSubset);
            this.entityLocation = entityLocation;
            this.stream = stream;
            this.reader = reader;
            this.encoding = encoding;
            this.literal = literal;
            this.mayReadChunks = mayReadChunks;
            this.isExternal = isExternal;
            this.fCharacterBuffer = fCharacterBufferPool.getBuffer(isExternal);
            this.ch = fCharacterBuffer.ch;
            this.fByteBuffer = byteBuffer;
        } // <init>(StringXMLResourceIdentifier,InputStream,Reader,String,boolean, boolean)

        //
        // Entity methods
        //

        
Returns true if this is an external entity. /** Returns true if this is an external entity. */
        public final boolean isExternal() {
            return isExternal;
        } // isExternal():boolean

        
Returns true if this is an unparsed entity. /** Returns true if this is an unparsed entity. */
        public final boolean isUnparsed() {
            return false;
        } // isUnparsed():boolean

        public void setReader(InputStream stream, String encoding, Boolean isBigEndian) throws IOException {
            fTempByteBuffer = fByteBuffer;
            reader = createReader(stream, encoding, isBigEndian);
            fByteBuffer = fTempByteBuffer;
        }

        // return the expanded system ID of the 
        // first external entity on the stack, null
        // otherwise.
        public String getExpandedSystemId() {

            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
               ScannedEntity externalEntity =
                    (ScannedEntity)fEntityStack.elementAt(i);

                if (externalEntity.entityLocation != null &&
                        externalEntity.entityLocation.getExpandedSystemId() != null) {
                    return externalEntity.entityLocation.getExpandedSystemId();
                }
            }
            return null;
        }

        // return literal systemId of
        // nearest external entity
        public String getLiteralSystemId() { 
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
               ScannedEntity externalEntity =
                    (ScannedEntity)fEntityStack.elementAt(i);

                if (externalEntity.entityLocation != null &&
                        externalEntity.entityLocation.getLiteralSystemId() != null) {
                    return externalEntity.entityLocation.getLiteralSystemId();
                }
            }
            return null;
        }
        
        // return line number of position in most
        // recent external entity
        public int getLineNumber() {
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0 ; --i) {
                ScannedEntity firstExternalEntity = (ScannedEntity)fEntityStack.elementAt(i);
                if (firstExternalEntity.isExternal()) {
                    return firstExternalEntity.lineNumber;
                }
            }
            return -1;
        }
        
        // return column number of position in most
        // recent external entity
        public int getColumnNumber() {
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
                ScannedEntity firstExternalEntity = (ScannedEntity)fEntityStack.elementAt(i);
                if (firstExternalEntity.isExternal()) {
                    return firstExternalEntity.columnNumber;
                }
            }
            return -1;
        }
        
        // return character offset of position in most
        // recent external entity
        public int getCharacterOffset() {
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
                ScannedEntity firstExternalEntity = (ScannedEntity)fEntityStack.elementAt(i);
                if (firstExternalEntity.isExternal()) {
                    return firstExternalEntity.baseCharOffset + (firstExternalEntity.position - firstExternalEntity.startPosition);
                }
            }
            return -1;
        }
        
        // return encoding of most recent external entity
        public String getEncoding() {
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
                ScannedEntity firstExternalEntity = (ScannedEntity)fEntityStack.elementAt(i);
                if (firstExternalEntity.isExternal()) {
                    return firstExternalEntity.encoding;
                }
            }
            return null;
        }
        
        // return xml version of most recent external entity
        public String getXMLVersion() {
            // search for the first external entity on the stack
            int size = fEntityStack.size();
            for (int i = size - 1; i >= 0; --i) {
                ScannedEntity firstExternalEntity = (ScannedEntity)fEntityStack.elementAt(i);
                if (firstExternalEntity.isExternal()) {
                    return firstExternalEntity.xmlVersion;
                }
            }
            return null;
        }
        
        
Returns whether the encoding of this entity was externally specified. /** Returns whether the encoding of this entity was externally specified. **/
        public boolean isEncodingExternallySpecified() {
            return externallySpecifiedEncoding;
        }
        
        
Sets whether the encoding of this entity was externally specified. /** Sets whether the encoding of this entity was externally specified. **/
        public void setEncodingExternallySpecified(boolean value) {
            externallySpecifiedEncoding = value;
        }
        
        //
        // Object methods
        //
        
        
Returns a string representation of this object. /** Returns a string representation of this object. */
        public String toString() {
            
            StringBuffer str = new StringBuffer();
            str.append("name=\"").append(name).append('"');
            str.append(",ch=");
            str.append(ch);
            str.append(",position=").append(position);
            str.append(",count=").append(count);
            str.append(",baseCharOffset=").append(baseCharOffset);
            str.append(",startPosition=").append(startPosition);
            return str.toString();
            
        } // toString():String

    } // class ScannedEntity
    
    
Information about auto-detectable encodings.
Author:
Michael Glavassevich, IBM
@xerces.internal
/**
     * Information about auto-detectable encodings.
     * 
     * @xerces.internal

     * 
     * @author Michael Glavassevich, IBM
     */
    private static class EncodingInfo {
        
        
UTF-8 /** UTF-8 **/
        public static final EncodingInfo UTF_8 = new EncodingInfo("UTF-8", null, false);
        
        
UTF-8, with BOM /** UTF-8, with BOM **/
        public static final EncodingInfo UTF_8_WITH_BOM = new EncodingInfo("UTF-8", null, true);
        
        
UTF-16, big-endian /** UTF-16, big-endian **/
        public static final EncodingInfo UTF_16_BIG_ENDIAN = new EncodingInfo("UTF-16BE", "UTF-16", Boolean.TRUE, false);
        
        
UTF-16, big-endian with BOM /** UTF-16, big-endian with BOM **/
        public static final EncodingInfo UTF_16_BIG_ENDIAN_WITH_BOM = new EncodingInfo("UTF-16BE", "UTF-16", Boolean.TRUE, true);
        
        
UTF-16, little-endian /** UTF-16, little-endian **/
        public static final EncodingInfo UTF_16_LITTLE_ENDIAN = new EncodingInfo("UTF-16LE", "UTF-16", Boolean.FALSE, false);
        
        
UTF-16, little-endian with BOM /** UTF-16, little-endian with BOM **/
        public static final EncodingInfo UTF_16_LITTLE_ENDIAN_WITH_BOM = new EncodingInfo("UTF-16LE", "UTF-16", Boolean.FALSE, true);
        
        
UCS-4, big-endian /** UCS-4, big-endian **/
        public static final EncodingInfo UCS_4_BIG_ENDIAN = new EncodingInfo("ISO-10646-UCS-4", Boolean.TRUE, false);
        
        
UCS-4, little-endian /** UCS-4, little-endian **/
        public static final EncodingInfo UCS_4_LITTLE_ENDIAN = new EncodingInfo("ISO-10646-UCS-4", Boolean.FALSE, false);
        
        
UCS-4, unusual byte-order (2143) or (3412) /** UCS-4, unusual byte-order (2143) or (3412) **/
        public static final EncodingInfo UCS_4_UNUSUAL_BYTE_ORDER = new EncodingInfo("ISO-10646-UCS-4", null, false);
        
        
EBCDIC /** EBCDIC **/
        public static final EncodingInfo EBCDIC = new EncodingInfo("CP037", null, false);
        
        public final String autoDetectedEncoding;
        public final String readerEncoding;
        public final Boolean isBigEndian;
        public final boolean hasBOM;
        
        private EncodingInfo(String autoDetectedEncoding, Boolean isBigEndian, boolean hasBOM) {
            this(autoDetectedEncoding, autoDetectedEncoding, isBigEndian, hasBOM);
        } // <init>(String,Boolean,boolean)
        
        private EncodingInfo(String autoDetectedEncoding, String readerEncoding, Boolean isBigEndian, boolean hasBOM) {
            this.autoDetectedEncoding = autoDetectedEncoding;
            this.readerEncoding = readerEncoding;
            this.isBigEndian = isBigEndian;
            this.hasBOM = hasBOM;
        } // <init>(String,String,Boolean,boolean)
        
    } // class EncodingInfo
    
    
Pool of byte buffers for the java.io.Readers.
Author:
Michael Glavassevich, IBM
@xerces.internal
/**
     * Pool of byte buffers for the java.io.Readers.
     * 
     * @xerces.internal

     * 
     * @author Michael Glavassevich, IBM
     */
    private static final class ByteBufferPool {
        
        private static final int DEFAULT_POOL_SIZE = 3;
        
        private int fPoolSize;
        private int fBufferSize;
        private byte[][] fByteBufferPool;
        private int fDepth;
        
        public ByteBufferPool(int bufferSize) {
            this(DEFAULT_POOL_SIZE, bufferSize);
        }
        
        public ByteBufferPool(int poolSize, int bufferSize) {
            fPoolSize = poolSize;
            fBufferSize = bufferSize;
            fByteBufferPool = new byte[fPoolSize][];
            fDepth = 0;
        }
        
        
Retrieves a byte buffer from the pool. /** Retrieves a byte buffer from the pool. **/
        public byte[] getBuffer() {
            return (fDepth > 0) ? fByteBufferPool[--fDepth] : new byte[fBufferSize];
        }
        
        
Returns byte buffer to pool. /** Returns byte buffer to pool. **/
        public void returnBuffer(byte[] buffer) {
            if (fDepth < fByteBufferPool.length) {
                fByteBufferPool[fDepth++] = buffer;
            }
        }

        
Sets the size of the buffers and dumps the old pool. /** Sets the size of the buffers and dumps the old pool. **/
        public void setBufferSize(int bufferSize) {
            fBufferSize = bufferSize;
            fByteBufferPool = new byte[fPoolSize][];
            fDepth = 0;
        } 
    }
    
    
Buffer used in entity manager to reuse character arrays instead
of creating new ones every time.
Author:
Ankit Pasricha, IBM
@xerces.internal
/**
     * Buffer used in entity manager to reuse character arrays instead
     * of creating new ones every time.
     * 
     * @xerces.internal

     * 
     * @author Ankit Pasricha, IBM
     */
    private static final class CharacterBuffer {

        
character buffer /** character buffer */
        private final char[] ch;
        
        
whether the buffer is for an external or internal scanned entity /** whether the buffer is for an external or internal scanned entity */
        private final boolean isExternal;
        
        public CharacterBuffer(boolean isExternal, int size) {
            this.isExternal = isExternal;
            ch = new char[size];
        }
    }
    
    
Stores a number of character buffers and provides it to the entity
manager to use when an entity is seen.
Author:
Ankit Pasricha, IBM
@xerces.internal
/**
     * Stores a number of character buffers and provides it to the entity
     * manager to use when an entity is seen.
     * 
     * @xerces.internal 
     * 
     * @author Ankit Pasricha, IBM
     */
    private static final class CharacterBufferPool {

        private static final int DEFAULT_POOL_SIZE = 3;
        
        private CharacterBuffer[] fInternalBufferPool;
        private CharacterBuffer[] fExternalBufferPool;

        private int fExternalBufferSize;
        private int fInternalBufferSize;
        private int fPoolSize;
        
        private int fInternalTop;
        private int fExternalTop;

        public CharacterBufferPool(int externalBufferSize, int internalBufferSize) {
            this(DEFAULT_POOL_SIZE, externalBufferSize, internalBufferSize);
        }
        
        public CharacterBufferPool(int poolSize, int externalBufferSize, int internalBufferSize) {
            fExternalBufferSize = externalBufferSize;
            fInternalBufferSize = internalBufferSize;
            fPoolSize = poolSize;
            init();
        }
        
        
Initializes buffer pool. /** Initializes buffer pool. **/
        private void init() {
            fInternalBufferPool = new CharacterBuffer[fPoolSize];
            fExternalBufferPool = new CharacterBuffer[fPoolSize];
            fInternalTop = -1;
            fExternalTop = -1;
        }

        
Retrieves buffer from pool. /** Retrieves buffer from pool. **/
        public CharacterBuffer getBuffer(boolean external) {
            if (external) {
                if (fExternalTop > -1) {
                    return (CharacterBuffer)fExternalBufferPool[fExternalTop--];
                }
                else {
                    return new CharacterBuffer(true, fExternalBufferSize);
                }
            }
            else {
                if (fInternalTop > -1) {
                    return (CharacterBuffer)fInternalBufferPool[fInternalTop--];
                }
                else {
                    return new CharacterBuffer(false, fInternalBufferSize);
                }
            }
        }
        
        
Returns buffer to pool. /** Returns buffer to pool. **/
        public void returnBuffer(CharacterBuffer buffer) {
            if (buffer.isExternal) {
                if (fExternalTop < fExternalBufferPool.length - 1) {
                    fExternalBufferPool[++fExternalTop] = buffer;
                }
            }
            else if (fInternalTop < fInternalBufferPool.length - 1) {
                fInternalBufferPool[++fInternalTop] = buffer;
            }
        }

        
Sets the size of external buffers and dumps the old pool. /** Sets the size of external buffers and dumps the old pool. **/
        public void setExternalBufferSize(int bufferSize) {
            fExternalBufferSize = bufferSize;
            fExternalBufferPool = new CharacterBuffer[fPoolSize];
            fExternalTop = -1;
        }
    }

    
This class wraps the byte inputstreams we're presented with.
We need it because java.io.InputStreams don't provide
functionality to reread processed bytes, and they have a habit
of reading more than one character when you call their read()
methods.  This means that, once we discover the true (declared)
encoding of a document, we can neither backtrack to read the
whole doc again nor start reading where we are with a new
reader.
This class allows rewinding an inputStream by allowing a mark
to be set, and the stream reset to that position.  The
class assumes that it needs to read one character per
invocation when it's read() method is inovked, but uses the
underlying InputStream's read(char[], offset length) method--it
won't buffer data read this way!
Author:
Neil Graham, IBM, Glenn Marcy, IBM
@xerces.internal
/**
     * This class wraps the byte inputstreams we're presented with.
     * We need it because java.io.InputStreams don't provide
     * functionality to reread processed bytes, and they have a habit
     * of reading more than one character when you call their read()
     * methods.  This means that, once we discover the true (declared)
     * encoding of a document, we can neither backtrack to read the
     * whole doc again nor start reading where we are with a new
     * reader.
     *
     * This class allows rewinding an inputStream by allowing a mark
     * to be set, and the stream reset to that position.  <strong>The
     * class assumes that it needs to read one character per
     * invocation when it's read() method is inovked, but uses the
     * underlying InputStream's read(char[], offset length) method--it
     * won't buffer data read this way!</strong>
     *
     * @xerces.internal

     *  
     * @author Neil Graham, IBM
     * @author Glenn Marcy, IBM
     */
    protected final class RewindableInputStream extends InputStream {

        private InputStream fInputStream;
        private byte[] fData;
        private int fStartOffset;
        private int fEndOffset;
        private int fOffset;
        private int fLength;
        private int fMark;

        public RewindableInputStream(InputStream is) {
            fData = new byte[DEFAULT_XMLDECL_BUFFER_SIZE];
            fInputStream = is;
            fStartOffset = 0;
            fEndOffset = -1;
            fOffset = 0;
            fLength = 0;
            fMark = 0;
        }

        public void setStartOffset(int offset) {
            fStartOffset = offset;
        }

        public void rewind() {
            fOffset = fStartOffset;
        }
        
        public int readAndBuffer() throws IOException {
            if (fOffset == fData.length) {
                byte[] newData = new byte[fOffset << 1];
                System.arraycopy(fData, 0, newData, 0, fOffset);
                fData = newData;
            }
            final int b = fInputStream.read();
            if (b == -1) {
                fEndOffset = fOffset;
                return -1;
            }
            fData[fLength++] = (byte)b;
            fOffset++;
            return b & 0xff;
        }

        public int read() throws IOException {
            if (fOffset < fLength) {
                return fData[fOffset++] & 0xff;
            }
            if (fOffset == fEndOffset) {
                return -1;
            }
            if (fCurrentEntity.mayReadChunks) {
                return fInputStream.read();
            }
            return readAndBuffer();
        }

        public int read(byte[] b, int off, int len) throws IOException {
            final int bytesLeft = fLength - fOffset;
            if (bytesLeft == 0) {
                if (fOffset == fEndOffset) {
                    return -1;
                }
                // better get some more for the voracious reader...
                if (fCurrentEntity.mayReadChunks) {
                    return fInputStream.read(b, off, len);
                }
                int returnedVal = readAndBuffer();
                if (returnedVal == -1) {
                    fEndOffset = fOffset;
                    return -1;
                }
                b[off] = (byte)returnedVal;
                return 1;
            }
            if (len < bytesLeft) {
                if (len <= 0) {
                    return 0;
                }
            }
            else {
                len = bytesLeft;
            }
            if (b != null) {
                System.arraycopy(fData, fOffset, b, off, len);
            }
            fOffset += len;
            return len;
        }

        public long skip(long n)
            throws IOException
        {
            int bytesLeft;
            if (n <= 0) {
                return 0;
            }
            bytesLeft = fLength - fOffset;
            if (bytesLeft == 0) {
                if (fOffset == fEndOffset) {
                    return 0;
                }
                return fInputStream.skip(n);
            }
            if (n <= bytesLeft) {
                fOffset += n;
                return n;
            }
            fOffset += bytesLeft;
            if (fOffset == fEndOffset) {
                return bytesLeft;
            }
            n -= bytesLeft;
           /*
            * In a manner of speaking, when this class isn't permitting more
            * than one byte at a time to be read, it is "blocking".  The
            * available() method should indicate how much can be read without
            * blocking, so while we're in this mode, it should only indicate
            * that bytes in its buffer are available; otherwise, the result of
            * available() on the underlying InputStream is appropriate.
            */
            return fInputStream.skip(n) + bytesLeft;
        }

        public int available() throws IOException {
            final int bytesLeft = fLength - fOffset;
            if (bytesLeft == 0) {
                if (fOffset == fEndOffset) {
                    return -1;
                }
                return fCurrentEntity.mayReadChunks ? fInputStream.available()
                                                    : 0;
            }
            return bytesLeft;
        }

        public void mark(int howMuch) {
            fMark = fOffset;
        }

        public void reset() {
            fOffset = fMark;
        }

        public boolean markSupported() {
            return true;
        }

        public void close() throws IOException {
            if (fInputStream != null) {
                fInputStream.close();
                fInputStream = null;
            }
        }
    } // end of RewindableInputStream class

} // class XMLEntityManager