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 * Copyright (c) 2000, 2006, 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

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package javax.xml.transform.sax;

import javax.xml.transform.Source;

import javax.xml.transform.stream.StreamSource;

import org.xml.sax.InputSource;

import org.xml.sax.XMLReader;

/**

 * <p>Acts as an holder for SAX-style Source.</p>

 *

 * <p>Note that XSLT requires namespace support. Attempting to transform an

 * input source that is not

 * generated with a namespace-aware parser may result in errors.

 * Parsers can be made namespace aware by calling the

 * {@link javax.xml.parsers.SAXParserFactory#setNamespaceAware(boolean awareness)} method.</p>

 *

 * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>

 */

public class SAXSource implements Source {

    /**

     * If {@link javax.xml.transform.TransformerFactory#getFeature}

     * returns true when passed this value as an argument,

     * the Transformer supports Source input of this type.

     */

    public static final String FEATURE =

        "http://javax.xml.transform.sax.SAXSource/feature";

    /**

     * <p>Zero-argument default constructor.  If this constructor is used, and

     * no SAX source is set using

     * {@link #setInputSource(InputSource inputSource)} , then the

     * <code>Transformer</code> will

     * create an empty source {@link org.xml.sax.InputSource} using

     * {@link org.xml.sax.InputSource#InputSource() new InputSource()}.</p>

     *

     * @see javax.xml.transform.Transformer#transform(Source xmlSource, Result outputTarget)

     */

    public SAXSource() { }

    /**

     * Create a <code>SAXSource</code>, using an {@link org.xml.sax.XMLReader}

     * and a SAX InputSource. The {@link javax.xml.transform.Transformer}

     * or {@link javax.xml.transform.sax.SAXTransformerFactory} will set itself

     * to be the reader's {@link org.xml.sax.ContentHandler}, and then will call

     * reader.parse(inputSource).

     *

     * @param reader An XMLReader to be used for the parse.

     * @param inputSource A SAX input source reference that must be non-null

     * and that will be passed to the reader parse method.

     */

    public SAXSource(XMLReader reader, InputSource inputSource) {

        this.reader      = reader;

        this.inputSource = inputSource;

    }

    /**

     * Create a <code>SAXSource</code>, using a SAX <code>InputSource</code>.

     * The {@link javax.xml.transform.Transformer} or

     * {@link javax.xml.transform.sax.SAXTransformerFactory} creates a

     * reader via {@link org.xml.sax.helpers.XMLReaderFactory}

     * (if setXMLReader is not used), sets itself as

     * the reader's {@link org.xml.sax.ContentHandler}, and calls

     * reader.parse(inputSource).

     *

     * @param inputSource An input source reference that must be non-null

     * and that will be passed to the parse method of the reader.

     */

    public SAXSource(InputSource inputSource) {

        this.inputSource = inputSource;

    }

    /**

     * Set the XMLReader to be used for the Source.

     *

     * @param reader A valid XMLReader or XMLFilter reference.

     */

    public void setXMLReader(XMLReader reader) {

        this.reader = reader;

    }

    /**

     * Get the XMLReader to be used for the Source.

     *

     * @return A valid XMLReader or XMLFilter reference, or null.

     */

    public XMLReader getXMLReader() {

        return reader;

    }

    /**

     * Set the SAX InputSource to be used for the Source.

     *

     * @param inputSource A valid InputSource reference.

     */

    public void setInputSource(InputSource inputSource) {

        this.inputSource = inputSource;

    }

    /**

     * Get the SAX InputSource to be used for the Source.

     *

     * @return A valid InputSource reference, or null.

     */

    public InputSource getInputSource() {

        return inputSource;

    }

    /**

     * Set the system identifier for this Source.  If an input source

     * has already been set, it will set the system ID or that

     * input source, otherwise it will create a new input source.

     *

     * <p>The system identifier is optional if there is a byte stream

     * or a character stream, but it is still useful to provide one,

     * since the application can use it to resolve relative URIs

     * and can include it in error messages and warnings (the parser

     * will attempt to open a connection to the URI only if

     * no byte stream or character stream is specified).</p>

     *

     * @param systemId The system identifier as a URI string.

     */

    public void setSystemId(String systemId) {

        if (null == inputSource) {

            inputSource = new InputSource(systemId);

        } else {

            inputSource.setSystemId(systemId);

        }

    }

    /**

     * <p>Get the base ID (URI or system ID) from where URIs

     * will be resolved.</p>

     *

     * @return Base URL for the <code>Source</code>, or <code>null</code>.

     */

    public String getSystemId() {

        if (inputSource == null) {

            return null;

        } else {

            return inputSource.getSystemId();

        }

    }

    /**

     * The XMLReader to be used for the source tree input. May be null.

     */

    private XMLReader reader;

    /**

     * <p>The SAX InputSource to be used for the source tree input.

     * Should not be <code>null</code>.</p>

     */

    private InputSource inputSource;

    /**

     * Attempt to obtain a SAX InputSource object from a Source

     * object.

     *

     * @param source Must be a non-null Source reference.

     *

     * @return An InputSource, or null if Source can not be converted.

     */

    public static InputSource sourceToInputSource(Source source) {

        if (source instanceof SAXSource) {

            return ((SAXSource) source).getInputSource();

        } else if (source instanceof StreamSource) {

            StreamSource ss      = (StreamSource) source;

            InputSource  isource = new InputSource(ss.getSystemId());

            isource.setByteStream(ss.getInputStream());

            isource.setCharacterStream(ss.getReader());

            isource.setPublicId(ss.getPublicId());

            return isource;

        } else {

            return null;

        }

    }

}