001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: https://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: https://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.pdftools.dtds;
029
030import java.io.IOException;
031import java.net.URL;
032
033import org.xml.sax.EntityResolver;
034import org.xml.sax.InputSource;
035import org.xml.sax.SAXException;
036
037/**
038 * Entity resolver for XHTML entities.<p>
039 */
040public class XhtmlEntityResolver implements EntityResolver {
041
042    /** The XHTML prefix. */
043    static final String XHTML_PREFIX = "http://www.w3.org/TR/xhtml1/DTD/";
044
045    /** The next entity resolver. */
046    private final EntityResolver m_next;
047
048    /**
049     * Constructor.<p>
050     */
051    public XhtmlEntityResolver() {
052
053        this(null);
054    }
055
056    /**
057     * Constructor.<p>
058     *
059     * @param next the next entity resolver.<p>
060     */
061    public XhtmlEntityResolver(EntityResolver next) {
062
063        m_next = next;
064    }
065
066    /**
067     * @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)
068     */
069    @Override
070    public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
071
072        if (systemId.startsWith(XHTML_PREFIX)) {
073            String name = systemId.substring(XHTML_PREFIX.length());
074            //final InputStream resourceAsStream = getClass().getResourceAsStream(name);
075            URL resource = getClass().getResource(name);
076            if (resource != null) {
077                InputSource inputSource = new InputSource(resource.toExternalForm());
078                inputSource.setPublicId(publicId);
079                //inputSource.setByteStream(resourceAsStream);
080                return inputSource;
081            }
082        }
083
084        // Let file: URLs just get loaded using the default mechanism
085        if (systemId.startsWith("file:") || systemId.startsWith("jar:")) {
086            return null;
087        }
088        if (m_next != null) {
089            return m_next.resolveEntity(publicId, systemId);
090        } else {
091            return null;
092        }
093    }
094}