/*
 * The MIT License
 * 
 * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi, Jorg Heymans
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
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package hudson.tasks.junit;

import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import java.io.IOException;
import java.net.URL;
import java.util.logging.Logger;

/**
 * As the name suggest: a resolver for XML entities.
 *
 * <p>
 * Basically, it provides the possibility to intercept online DTD lookups
 * and instead do offline lookup by redirecting to a local directory where
 * .dtd's are stored
 *
 * (useful when parsing testng-results.xml - which points to testng.org)
 *
 * @author Mikael Carneholm
 */
class XMLEntityResolver implements EntityResolver {

    private static final String TESTNG_NAMESPACE = "http://testng.org/";

    /**
     * Intercepts the lookup of publicId, systemId
     */
    public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
        if (systemId != null) {
            LOGGER.fine("Will try to resolve systemId [" + systemId + "]");
            // TestNG system-ids
            if (systemId.startsWith(TESTNG_NAMESPACE)) {
                LOGGER.fine("It's a TestNG document, will try to lookup DTD in classpath");
                String dtdFileName = systemId.substring(TESTNG_NAMESPACE.length());

                URL url = getClass().getClassLoader().getResource(dtdFileName);
                if (url != null)
                    return new InputSource(url.toString());
            }
        }
        // Default fallback
        return null;
    }

    private static final Logger LOGGER = Logger.getLogger(XMLEntityResolver.class.getName());
}