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	/*
	* Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	// XMLFilterImpl.java - base SAX2 filter implementation.
	// http://www.saxproject.org
	// Written by David Megginson
	// NO WARRANTY! This class is in the Public Domain.
	// $Id: XMLFilterImpl.java,v 1.3 2004/11/03 22:53:09 jsuttor Exp $

	package org.xml.sax.helpers;

	import java.io.IOException;

	import org.xml.sax.XMLReader;
	import org.xml.sax.XMLFilter;
	import org.xml.sax.InputSource;
	import org.xml.sax.Locator;
	import org.xml.sax.Attributes;
	import org.xml.sax.EntityResolver;
	import org.xml.sax.DTDHandler;
	import org.xml.sax.ContentHandler;
	import org.xml.sax.ErrorHandler;
	import org.xml.sax.SAXException;
	import org.xml.sax.SAXParseException;
	import org.xml.sax.SAXNotSupportedException;
	import org.xml.sax.SAXNotRecognizedException;


	/**
	* Base class for deriving an XML filter.
	*
	* <blockquote>
	* <em>This module, both source code and documentation, is in the
	* Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
	* See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
	* for further information.
	* </blockquote>
	*
	* <p>This class is designed to sit between an {@link org.xml.sax.XMLReader
	* XMLReader} and the client application's event handlers. By default, it
	* does nothing but pass requests up to the reader and events
	* on to the handlers unmodified, but subclasses can override
	* specific methods to modify the event stream or the configuration
	* requests as they pass through.</p>
	*
	* @since 1.4, SAX 2.0
	* @author David Megginson
	* @see org.xml.sax.XMLFilter
	* @see org.xml.sax.XMLReader
	* @see org.xml.sax.EntityResolver
	* @see org.xml.sax.DTDHandler
	* @see org.xml.sax.ContentHandler
	* @see org.xml.sax.ErrorHandler
	*/
	public class XMLFilterImpl
	implements XMLFilter, EntityResolver, DTDHandler, ContentHandler, ErrorHandler
	{


	////////////////////////////////////////////////////////////////////
	// Constructors.
	////////////////////////////////////////////////////////////////////


	/**
	* Construct an empty XML filter, with no parent.
	*
	* <p>This filter will have no parent: you must assign a parent
	* before you start a parse or do any configuration with
	* setFeature or setProperty, unless you use this as a pure event
	* consumer rather than as an {@link XMLReader}.</p>
	*
	* @see org.xml.sax.XMLReader#setFeature
	* @see org.xml.sax.XMLReader#setProperty
	* @see #setParent
	*/
	public XMLFilterImpl ()
	{
	super();
	}


	/**
	* Construct an XML filter with the specified parent.
	*
	* @see #setParent
	* @see #getParent
	*/
	public XMLFilterImpl (XMLReader parent)
	{
	super();
	setParent(parent);
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.XMLFilter.
	////////////////////////////////////////////////////////////////////


	/**
	* Set the parent reader.
	*
	* <p>This is the {@link org.xml.sax.XMLReader XMLReader} from which
	* this filter will obtain its events and to which it will pass its
	* configuration requests. The parent may itself be another filter.</p>
	*
	* <p>If there is no parent reader set, any attempt to parse
	* or to set or get a feature or property will fail.</p>
	*
	* @param parent The parent XML reader.
	* @see #getParent
	*/
	public void setParent (XMLReader parent)
	{
	this.parent = parent;
	}


	/**
	* Get the parent reader.
	*
	* @return The parent XML reader, or null if none is set.
	* @see #setParent
	*/
	public XMLReader getParent ()
	{
	return parent;
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.XMLReader.
	////////////////////////////////////////////////////////////////////


	/**
	* Set the value of a feature.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The feature name.
	* @param value The requested feature value.
	* @exception org.xml.sax.SAXNotRecognizedException If the feature
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the feature name but
	* cannot set the requested value.
	*/
	public void setFeature (String name, boolean value)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	parent.setFeature(name, value);
	} else {
	throw new SAXNotRecognizedException("Feature: " + name);
	}
	}


	/**
	* Look up the value of a feature.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The feature name.
	* @return The current value of the feature.
	* @exception org.xml.sax.SAXNotRecognizedException If the feature
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the feature name but
	* cannot determine its value at this time.
	*/
	public boolean getFeature (String name)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	return parent.getFeature(name);
	} else {
	throw new SAXNotRecognizedException("Feature: " + name);
	}
	}


	/**
	* Set the value of a property.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The property name.
	* @param value The requested property value.
	* @exception org.xml.sax.SAXNotRecognizedException If the property
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the property name but
	* cannot set the requested value.
	*/
	public void setProperty (String name, Object value)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	parent.setProperty(name, value);
	} else {
	throw new SAXNotRecognizedException("Property: " + name);
	}
	}


	/**
	* Look up the value of a property.
	*
	* @param name The property name.
	* @return The current value of the property.
	* @exception org.xml.sax.SAXNotRecognizedException If the property
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the property name but
	* cannot determine its value at this time.
	*/
	public Object getProperty (String name)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	return parent.getProperty(name);
	} else {
	throw new SAXNotRecognizedException("Property: " + name);
	}
	}


	/**
	* Set the entity resolver.
	*
	* @param resolver The new entity resolver.
	*/
	public void setEntityResolver (EntityResolver resolver)
	{
	entityResolver = resolver;
	}


	/**
	* Get the current entity resolver.
	*
	* @return The current entity resolver, or null if none was set.
	*/
	public EntityResolver getEntityResolver ()
	{
	return entityResolver;
	}


	/**
	* Set the DTD event handler.
	*
	* @param handler the new DTD handler
	*/
	public void setDTDHandler (DTDHandler handler)
	{
	dtdHandler = handler;
	}


	/**
	* Get the current DTD event handler.
	*
	* @return The current DTD handler, or null if none was set.
	*/
	public DTDHandler getDTDHandler ()
	{
	return dtdHandler;
	}


	/**
	* Set the content event handler.
	*
	* @param handler the new content handler
	*/
	public void setContentHandler (ContentHandler handler)
	{
	contentHandler = handler;
	}


	/**
	* Get the content event handler.
	*
	* @return The current content handler, or null if none was set.
	*/
	public ContentHandler getContentHandler ()
	{
	return contentHandler;
	}


	/**
	* Set the error event handler.
	*
	* @param handler the new error handler
	*/
	public void setErrorHandler (ErrorHandler handler)
	{
	errorHandler = handler;
	}


	/**
	* Get the current error event handler.
	*
	* @return The current error handler, or null if none was set.
	*/
	public ErrorHandler getErrorHandler ()
	{
	return errorHandler;
	}


	/**
	* Parse a document.
	*
	* @param input The input source for the document entity.
	* @exception org.xml.sax.SAXException Any SAX exception, possibly
	* wrapping another exception.
	* @exception java.io.IOException An IO exception from the parser,
	* possibly from a byte stream or character stream
	* supplied by the application.
	*/
	public void parse (InputSource input)
	throws SAXException, IOException
	{
	setupParse();
	parent.parse(input);
	}


	/**
	* Parse a document.
	*
	* @param systemId The system identifier as a fully-qualified URI.
	* @exception org.xml.sax.SAXException Any SAX exception, possibly
	* wrapping another exception.
	* @exception java.io.IOException An IO exception from the parser,
	* possibly from a byte stream or character stream
	* supplied by the application.
	*/
	public void parse (String systemId)
	throws SAXException, IOException
	{
	parse(new InputSource(systemId));
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.EntityResolver.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter an external entity resolution.
	*
	* @param publicId The entity's public identifier, or null.
	* @param systemId The entity's system identifier.
	* @return A new InputSource or null for the default.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	* @exception java.io.IOException The client may throw an
	* I/O-related exception while obtaining the
	* new InputSource.
	*/
	public InputSource resolveEntity (String publicId, String systemId)
	throws SAXException, IOException
	{
	if (entityResolver != null) {
	return entityResolver.resolveEntity(publicId, systemId);
	} else {
	return null;
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.DTDHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a notation declaration event.
	*
	* @param name The notation name.
	* @param publicId The notation's public identifier, or null.
	* @param systemId The notation's system identifier, or null.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void notationDecl (String name, String publicId, String systemId)
	throws SAXException
	{
	if (dtdHandler != null) {
	dtdHandler.notationDecl(name, publicId, systemId);
	}
	}


	/**
	* Filter an unparsed entity declaration event.
	*
	* @param name The entity name.
	* @param publicId The entity's public identifier, or null.
	* @param systemId The entity's system identifier, or null.
	* @param notationName The name of the associated notation.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void unparsedEntityDecl (String name, String publicId,
	String systemId, String notationName)
	throws SAXException
	{
	if (dtdHandler != null) {
	dtdHandler.unparsedEntityDecl(name, publicId, systemId,
	notationName);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.ContentHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a new document locator event.
	*
	* @param locator The document locator.
	*/
	public void setDocumentLocator (Locator locator)
	{
	this.locator = locator;
	if (contentHandler != null) {
	contentHandler.setDocumentLocator(locator);
	}
	}


	/**
	* Filter a start document event.
	*
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startDocument ()
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startDocument();
	}
	}


	/**
	* Filter an end document event.
	*
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endDocument ()
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endDocument();
	}
	}


	/**
	* Filter a start Namespace prefix mapping event.
	*
	* @param prefix The Namespace prefix.
	* @param uri The Namespace URI.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startPrefixMapping (String prefix, String uri)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startPrefixMapping(prefix, uri);
	}
	}


	/**
	* Filter an end Namespace prefix mapping event.
	*
	* @param prefix The Namespace prefix.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endPrefixMapping (String prefix)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endPrefixMapping(prefix);
	}
	}


	/**
	* Filter a start element event.
	*
	* @param uri The element's Namespace URI, or the empty string.
	* @param localName The element's local name, or the empty string.
	* @param qName The element's qualified (prefixed) name, or the empty
	* string.
	* @param atts The element's attributes.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startElement (String uri, String localName, String qName,
	Attributes atts)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startElement(uri, localName, qName, atts);
	}
	}


	/**
	* Filter an end element event.
	*
	* @param uri The element's Namespace URI, or the empty string.
	* @param localName The element's local name, or the empty string.
	* @param qName The element's qualified (prefixed) name, or the empty
	* string.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endElement (String uri, String localName, String qName)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endElement(uri, localName, qName);
	}
	}


	/**
	* Filter a character data event.
	*
	* @param ch An array of characters.
	* @param start The starting position in the array.
	* @param length The number of characters to use from the array.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void characters (char ch[], int start, int length)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.characters(ch, start, length);
	}
	}


	/**
	* Filter an ignorable whitespace event.
	*
	* @param ch An array of characters.
	* @param start The starting position in the array.
	* @param length The number of characters to use from the array.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void ignorableWhitespace (char ch[], int start, int length)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.ignorableWhitespace(ch, start, length);
	}
	}


	/**
	* Filter a processing instruction event.
	*
	* @param target The processing instruction target.
	* @param data The text following the target.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void processingInstruction (String target, String data)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.processingInstruction(target, data);
	}
	}


	/**
	* Filter a skipped entity event.
	*
	* @param name The name of the skipped entity.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void skippedEntity (String name)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.skippedEntity(name);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.ErrorHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a warning event.
	*
	* @param e The warning as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void warning (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.warning(e);
	}
	}


	/**
	* Filter an error event.
	*
	* @param e The error as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void error (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.error(e);
	}
	}


	/**
	* Filter a fatal error event.
	*
	* @param e The error as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void fatalError (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.fatalError(e);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Internal methods.
	////////////////////////////////////////////////////////////////////


	/**
	* Set up before a parse.
	*
	* <p>Before every parse, check whether the parent is
	* non-null, and re-register the filter for all of the
	* events.</p>
	*/
	private void setupParse ()
	{
	if (parent == null) {
	throw new NullPointerException("No parent for filter");
	}
	parent.setEntityResolver(this);
	parent.setDTDHandler(this);
	parent.setContentHandler(this);
	parent.setErrorHandler(this);
	}



	////////////////////////////////////////////////////////////////////
	// Internal state.
	////////////////////////////////////////////////////////////////////

	private XMLReader parent = null;
	private Locator locator = null;
	private EntityResolver entityResolver = null;
	private DTDHandler dtdHandler = null;
	private ContentHandler contentHandler = null;
	private ErrorHandler errorHandler = null;

	}

	// end of XMLFilterImpl.java

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