SaxParserLexicalHandler.java

/**
 * JHOVE2 - Next-generation architecture for format-aware characterization
 * <p>
 * Copyright (c) 2009 by The Regents of the University of California, Ithaka
 * Harbors, Inc., and The Board of Trustees of the Leland Stanford Junior
 * University. All rights reserved.
 * </p>
 * <p>
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * </p>
 * <ul>
 * <li>Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.</li>
 * <li>Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.</li>
 * <li>Neither the name of the University of California/California Digital
 * Library, Ithaka Harbors/Portico, or Stanford University, nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.</li>
 * </ul>
 * <p>
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * </p>
 */
package org.jhove2.module.format.xml;

import org.xml.sax.SAXException;
import org.xml.sax.ext.DefaultHandler2;
import org.xml.sax.ext.LexicalHandler;

/**
 * An instance of this class is registered with the SAX parser to handle events
 * related to the lexical information about an XML document. In this application, the
 * information about DTD declarations, entity references, and comments is captured
 * 
 * @author rnanders
 * @see <a
 *      href="http://www.saxproject.org/apidoc/org/xml/sax/ext/LexicalHandler.html">LexicalHandler javadoc</a>
 */
public class SaxParserLexicalHandler extends DefaultHandler2 implements
        LexicalHandler {

    /** The XmlModule object that is invoking the parser. */
    private XmlModule xmlModule;

    /**
     * Instantiates a new SaxParserDeclHandler object.
     * 
     * @param xmlModule
     *            the XmlModule object that is invoking the parser
     */
    public SaxParserLexicalHandler(XmlModule xmlModule) {
        this.xmlModule = xmlModule;
    }

    /**
     * Report an XML comment anywhere in the document.
     */
    @Override
    public void comment(char[] ch, int start, int length) throws SAXException {
        xmlModule.commentInformation.add(String.copyValueOf(ch, start, length));
    }

    /**
     * Report the start of DTD declarations, if any.
     */
    @Override
    public void startDTD(String name, String publicId, String systemId)
            throws SAXException {
        DTD dtd = new DTD();
        dtd.name = name;
        dtd.publicID = publicId;
        dtd.systemID = systemId;
        xmlModule.dtds.add(dtd);
    }

    /**
     * Report the use of XML entities.
     */
    @Override
    public void startEntity(String name) throws SAXException {
        xmlModule.entityReferences.tally(name);
    }

}