root/src/jomdoc/trunk/src/jomdoc/org/omdoc/jomdoc/util/resolver/DefaultJOMDocURIResolver.java

/*
 * JOMDoc - A Java library for OMDoc documents (http://omdoc.org/jomdoc).
 *
 * Original author    Dimitar Misev <d.misev@jacobs-university.de>
 * Web                http://kwarc.info/dmisev/
 * Created            Feb 6, 2010, 11:57:26 AM
 *
 * Filename           $Id$
 * Revision           $Revision$
 * Last modified on   $Date$
 *               by   $Author$
 *
 * Copyright (C) 2007,2008 the KWARC group (http://kwarc.info)
 * Licensed under the GNU Public License v3 (GPL3).
 * For other licensing contact Michael Kohlhase <m.kohlhase@jacobs-university.de>
 */
package org.omdoc.jomdoc.util.resolver;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URI;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.stream.StreamSource;
import nu.xom.Document;
import nu.xom.ParsingException;
import org.omdoc.jomdoc.util.etc.Log;
import org.omdoc.jomdoc.util.types.Pair;
import org.omdoc.jomdoc.util.xml.XMLUtil;
import org.omdoc.jomdoc.util.xml.XSLTUtil;

/**
 * This is the default URI resolver used in JOMDoc. It provides resolving of local filesystem
 * or http resources.
 *
 * @author <a href="mailto:d.misev@jacobs-university.de">Dimitar Misev</a>
 */
public class DefaultJOMDocURIResolver extends AbstractJOMDocURIResolver {

    public DefaultJOMDocURIResolver() {
        super("file", "http");
    }

    public DefaultJOMDocURIResolver(String... supportedSchemes) {
        super(supportedSchemes);
    }

    public Pair<InputStream, URI> resolveInputStream(String href, String base) throws ResolveException {
        if (!isSchemaSupported(href, base, true)) {
            return null;
        }
        URI absolute = URIUtil.toAbsoluteURI(href, base);
        try {
            return Pair.of(absolute.toURL().openStream(), absolute);
        } catch (MalformedURLException ex) {
            throw new ResolveException("Error converting the given URI " + absolute + " to URL", ex);
        } catch (IOException ex) {
            throw new ResolveException("I/O error while opening stream to " + absolute, ex);
        }
    }

    @Override
    public Document resolveDocument(String href, String base) throws ResolveException {
        Pair<InputStream, URI> res = resolveInputStream(href, base);
        if (res == null) {
            return null;
        }
        InputStream is = res.fst;
        String uri = (res.snd == null) ? null : res.snd.toString();
        try {
            return XMLUtil.buildDocument(uri, is);
        } catch (IOException ex) {
            log.warn(Log.array("Error reading document at " + uri, ex));
        } catch (ParsingException ex) {
            log.warn(Log.array("Error parsing document at " + uri, ex));
        }
        return null;
    }

    @Override
    public Source resolve(String href, String base) throws TransformerException {
        if (!isSchemaSupported(href, base, true)) {
            return null;
        }
        String absolute = null;
        try {
            absolute = URIUtil.toAbsoluteURI(href, base).getPath();
//            log.warn("Href: " + href + "\nbase: " + base + "\nabsolute: " + absolute + "\n");
            href = absolute.substring(1); // remove leading /
        } catch (ResolveException ex) {
            throw new TransformerException("Error resolving uri " + href + " to absolute, against base: " + base, ex);
        }
        InputStream is = null;
        try {
            is = XSLTUtil.class.getClassLoader().getResourceAsStream(href);
        } catch (Exception ex) {
//            log.warn("Error resolving resource during transformation: " + href);
        }
        if (is != null) {
            return new StreamSource(is, absolute);
        } else {
            return null;
        }
    }

}