Subversion Repositories openrisc

// XMLReaderAdapter.java - adapt an SAX2 XMLReader to a SAX1 Parser

// http://www.saxproject.org

// Written by David Megginson

// NO WARRANTY!  This class is in the public domain.

// $Id: XMLReaderAdapter.java,v 1.2 2006/12/10 20:25:41 gnu_andrew Exp $

package org.xml.sax.helpers;

import java.io.IOException;

import java.util.Locale;

import org.xml.sax.Parser;      // deprecated

import org.xml.sax.Locator;

import org.xml.sax.InputSource;

import org.xml.sax.AttributeList; // deprecated

import org.xml.sax.EntityResolver;

import org.xml.sax.DTDHandler;

import org.xml.sax.DocumentHandler; // deprecated

import org.xml.sax.ErrorHandler;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

import org.xml.sax.Attributes;

import org.xml.sax.ContentHandler;

import org.xml.sax.SAXNotSupportedException;

/**

 * Adapt a SAX2 XMLReader as a SAX1 Parser.

 *

 * <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 wraps a SAX2 {@link org.xml.sax.XMLReader XMLReader}

 * and makes it act as a SAX1 {@link org.xml.sax.Parser Parser}.  The XMLReader

 * must support a true value for the

 * http://xml.org/sax/features/namespace-prefixes property or parsing will fail

 * with a {@link org.xml.sax.SAXException SAXException}; if the XMLReader

 * supports a false value for the http://xml.org/sax/features/namespaces

 * property, that will also be used to improve efficiency.</p>

 *

 * @since SAX 2.0

 * @author David Megginson

 * @version 2.0.1 (sax2r2)

 * @see org.xml.sax.Parser

 * @see org.xml.sax.XMLReader

 */

public class XMLReaderAdapter implements Parser, ContentHandler

{

    ////////////////////////////////////////////////////////////////////

    // Constructor.

    ////////////////////////////////////////////////////////////////////

    /**

     * Create a new adapter.

     *

     * <p>Use the "org.xml.sax.driver" property to locate the SAX2

     * driver to embed.</p>

     *

     * @exception org.xml.sax.SAXException If the embedded driver

     *            cannot be instantiated or if the

     *            org.xml.sax.driver property is not specified.

     */

    public XMLReaderAdapter ()

      throws SAXException

    {

        setup(XMLReaderFactory.createXMLReader());

    }

    /**

     * Create a new adapter.

     *

     * <p>Create a new adapter, wrapped around a SAX2 XMLReader.

     * The adapter will make the XMLReader act like a SAX1

     * Parser.</p>

     *

     * @param xmlReader The SAX2 XMLReader to wrap.

     * @exception java.lang.NullPointerException If the argument is null.

     */

    public XMLReaderAdapter (XMLReader xmlReader)

    {

        setup(xmlReader);

    }

    /**

     * Internal setup.

     *

     * @param xmlReader The embedded XMLReader.

     */

    private void setup (XMLReader xmlReader)

    {

        if (xmlReader == null) {

            throw new NullPointerException("XMLReader must not be null");

        }

        this.xmlReader = xmlReader;

        qAtts = new AttributesAdapter();

    }

    ////////////////////////////////////////////////////////////////////

    // Implementation of org.xml.sax.Parser.

    ////////////////////////////////////////////////////////////////////

    /**

     * Set the locale for error reporting.

     *

     * <p>This is not supported in SAX2, and will always throw

     * an exception.</p>

     *

     * @param locale the locale for error reporting.

     * @see org.xml.sax.Parser#setLocale

     * @exception org.xml.sax.SAXException Thrown unless overridden.

     */

    public void setLocale (Locale locale)

        throws SAXException

    {

        throw new SAXNotSupportedException("setLocale not supported");

    }

    /**

     * Register the entity resolver.

     *

     * @param resolver The new resolver.

     * @see org.xml.sax.Parser#setEntityResolver

     */

    public void setEntityResolver (EntityResolver resolver)

    {

        xmlReader.setEntityResolver(resolver);

    }

    /**

     * Register the DTD event handler.

     *

     * @param handler The new DTD event handler.

     * @see org.xml.sax.Parser#setDTDHandler

     */

    public void setDTDHandler (DTDHandler handler)

    {

        xmlReader.setDTDHandler(handler);

    }

    /**

     * Register the SAX1 document event handler.

     *

     * <p>Note that the SAX1 document handler has no Namespace

     * support.</p>

     *

     * @param handler The new SAX1 document event handler.

     * @see org.xml.sax.Parser#setDocumentHandler

     */

    public void setDocumentHandler (DocumentHandler handler)

    {

        documentHandler = handler;

    }

    /**

     * Register the error event handler.

     *

     * @param handler The new error event handler.

     * @see org.xml.sax.Parser#setErrorHandler

     */

    public void setErrorHandler (ErrorHandler handler)

    {

        xmlReader.setErrorHandler(handler);

    }

    /**

     * Parse the document.

     *

     * <p>This method will throw an exception if the embedded

     * XMLReader does not support the

     * http://xml.org/sax/features/namespace-prefixes property.</p>

     *

     * @param systemId The absolute URL of the document.

     * @exception java.io.IOException If there is a problem reading

     *            the raw content of the document.

     * @exception org.xml.sax.SAXException If there is a problem

     *            processing the document.

     * @see #parse(org.xml.sax.InputSource)

     * @see org.xml.sax.Parser#parse(java.lang.String)

     */

    public void parse (String systemId)

        throws IOException, SAXException

    {

        parse(new InputSource(systemId));

    }

    /**

     * Parse the document.

     *

     * <p>This method will throw an exception if the embedded

     * XMLReader does not support the

     * http://xml.org/sax/features/namespace-prefixes property.</p>

     *

     * @param input An input source for the document.

     * @exception java.io.IOException If there is a problem reading

     *            the raw content of the document.

     * @exception org.xml.sax.SAXException If there is a problem

     *            processing the document.

     * @see #parse(java.lang.String)

     * @see org.xml.sax.Parser#parse(org.xml.sax.InputSource)

     */

    public void parse (InputSource input)

        throws IOException, SAXException

    {

        setupXMLReader();

        xmlReader.parse(input);

    }

    /**

     * Set up the XML reader.

     */

    private void setupXMLReader ()

        throws SAXException

    {

        xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);

        try {

            xmlReader.setFeature("http://xml.org/sax/features/namespaces",

                                 false);

        } catch (SAXException e) {

            // NO OP: it's just extra information, and we can ignore it

        }

        xmlReader.setContentHandler(this);

    }

    ////////////////////////////////////////////////////////////////////

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

    ////////////////////////////////////////////////////////////////////

    /**

     * Set a document locator.

     *

     * @param locator The document locator.

     * @see org.xml.sax.ContentHandler#setDocumentLocator

     */

    public void setDocumentLocator (Locator locator)

    {

        if (documentHandler != null)

            documentHandler.setDocumentLocator(locator);

    }

    /**

     * Start document event.

     *

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#startDocument

     */

    public void startDocument ()

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.startDocument();

    }

    /**

     * End document event.

     *

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#endDocument

     */

    public void endDocument ()

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.endDocument();

    }

    /**

     * Adapt a SAX2 start prefix mapping event.

     *

     * @param prefix The prefix being mapped.

     * @param uri The Namespace URI being mapped to.

     * @see org.xml.sax.ContentHandler#startPrefixMapping

     */

    public void startPrefixMapping (String prefix, String uri)

    {

    }

    /**

     * Adapt a SAX2 end prefix mapping event.

     *

     * @param prefix The prefix being mapped.

     * @see org.xml.sax.ContentHandler#endPrefixMapping

     */

    public void endPrefixMapping (String prefix)

    {

    }

    /**

     * Adapt a SAX2 start element event.

     *

     * @param uri The Namespace URI.

     * @param localName The Namespace local name.

     * @param qName The qualified (prefixed) name.

     * @param atts The SAX2 attributes.

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#endDocument

     */

    public void startElement (String uri, String localName,

                              String qName, Attributes atts)

        throws SAXException

    {

        if (documentHandler != null) {

            qAtts.setAttributes(atts);

            documentHandler.startElement(qName, qAtts);

        }

    }

    /**

     * Adapt a SAX2 end element event.

     *

     * @param uri The Namespace URI.

     * @param localName The Namespace local name.

     * @param qName The qualified (prefixed) name.

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#endElement

     */

    public void endElement (String uri, String localName,

                            String qName)

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.endElement(qName);

    }

    /**

     * Adapt a SAX2 characters event.

     *

     * @param ch An array of characters.

     * @param start The starting position in the array.

     * @param length The number of characters to use.

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#characters

     */

    public void characters (char ch[], int start, int length)

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.characters(ch, start, length);

    }

    /**

     * Adapt a SAX2 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.

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#ignorableWhitespace

     */

    public void ignorableWhitespace (char ch[], int start, int length)

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.ignorableWhitespace(ch, start, length);

    }

    /**

     * Adapt a SAX2 processing instruction event.

     *

     * @param target The processing instruction target.

     * @param data The remainder of the processing instruction

     * @exception org.xml.sax.SAXException The client may raise a

     *            processing exception.

     * @see org.xml.sax.ContentHandler#processingInstruction

     */

    public void processingInstruction (String target, String data)

        throws SAXException

    {

        if (documentHandler != null)

            documentHandler.processingInstruction(target, data);

    }

    /**

     * Adapt a SAX2 skipped entity event.

     *

     * @param name The name of the skipped entity.

     * @see org.xml.sax.ContentHandler#skippedEntity

     * @exception org.xml.sax.SAXException Throwable by subclasses.

     */

    public void skippedEntity (String name)

        throws SAXException

    {

    }

    ////////////////////////////////////////////////////////////////////

    // Internal state.

    ////////////////////////////////////////////////////////////////////

    XMLReader xmlReader;

    DocumentHandler documentHandler;

    AttributesAdapter qAtts;

    ////////////////////////////////////////////////////////////////////

    // Internal class.

    ////////////////////////////////////////////////////////////////////

    /**

     * Internal class to wrap a SAX2 Attributes object for SAX1.

     */

    final class AttributesAdapter implements AttributeList

    {

        AttributesAdapter ()

        {

        }

        /**

         * Set the embedded Attributes object.

         *

         * @param The embedded SAX2 Attributes.

         */

        void setAttributes (Attributes attributes)

        {

            this.attributes = attributes;

        }

        /**

         * Return the number of attributes.

         *

         * @return The length of the attribute list.

         * @see org.xml.sax.AttributeList#getLength

         */

        public int getLength ()

        {

            return attributes.getLength();

        }

        /**

         * Return the qualified (prefixed) name of an attribute by position.

         *

         * @return The qualified name.

         * @see org.xml.sax.AttributeList#getName

         */

        public String getName (int i)

        {

            return attributes.getQName(i);

        }

        /**

         * Return the type of an attribute by position.

         *

         * @return The type.

         * @see org.xml.sax.AttributeList#getType(int)

         */

        public String getType (int i)

        {

            return attributes.getType(i);

        }

        /**

         * Return the value of an attribute by position.

         *

         * @return The value.

         * @see org.xml.sax.AttributeList#getValue(int)

         */

        public String getValue (int i)

        {

            return attributes.getValue(i);

        }

        /**

         * Return the type of an attribute by qualified (prefixed) name.

         *

         * @return The type.

         * @see org.xml.sax.AttributeList#getType(java.lang.String)

         */

        public String getType (String qName)

        {

            return attributes.getType(qName);

        }

        /**

         * Return the value of an attribute by qualified (prefixed) name.

         *

         * @return The value.

         * @see org.xml.sax.AttributeList#getValue(java.lang.String)

         */

        public String getValue (String qName)

        {

            return attributes.getValue(qName);

        }

        private Attributes attributes;

    }

}

// end of XMLReaderAdapter.java