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 * 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,

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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.

 *

 * <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.