001    /*
002     * 
003     * $Revision: 13085 $ $Date: 2008-02-06 18:27:24 +0100 (Mi, 06 Feb 2008) $
004     *
005     * This file is part of ***  M y C o R e  ***
006     * See http://www.mycore.de/ for details.
007     *
008     * This program is free software; you can use it, redistribute it
009     * and / or modify it under the terms of the GNU General Public License
010     * (GPL) as published by the Free Software Foundation; either version 2
011     * of the License or (at your option) any later version.
012     *
013     * This program is distributed in the hope that it will be useful, but
014     * WITHOUT ANY WARRANTY; without even the implied warranty of
015     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016     * GNU General Public License for more details.
017     *
018     * You should have received a copy of the GNU General Public License
019     * along with this program, in a file called gpl.txt or license.txt.
020     * If not, write to the Free Software Foundation Inc.,
021     * 59 Temple Place - Suite 330, Boston, MA  02111-1307 USA
022     */
023    
024    package org.mycore.datamodel.ifs.extractors;
025    
026    import java.io.InputStream;
027    import java.util.Iterator;
028    
029    import org.apache.log4j.Logger;
030    import org.jdom.Element;
031    
032    import com.drew.imaging.jpeg.JpegMetadataReader;
033    import com.drew.imaging.jpeg.JpegProcessingException;
034    import com.drew.metadata.Directory;
035    import com.drew.metadata.Metadata;
036    import com.drew.metadata.Tag;
037    
038    /**
039     * Extracts EXIF and IPTC metadata from JPEG files. Uses the metadata extraction
040     * library from Drew Noakes in the com.drew.** packages. See
041     * http://www.drewnoakes.com/code/exif/ for details.
042     * 
043     * @author Frank Lützenkirchen
044     * @version $Revision: 13085 $ $Date: 2008-02-06 18:27:24 +0100 (Mi, 06 Feb 2008) $
045     */
046    public class MCRDataExtractorJPEG extends MCRDataExtractor {
047    
048        /** The logger */
049        private final static Logger LOGGER = Logger.getLogger(MCRDataExtractorJPEG.class);
050    
051        protected String getSupportedContentTypeIDs() {
052            return "jpeg";
053        }
054    
055        protected void extractData(Element container, InputStream in) throws JpegProcessingException {
056            Metadata metadata = JpegMetadataReader.readMetadata(in);
057            Iterator directories = metadata.getDirectoryIterator();
058            while (directories.hasNext()) {
059                Directory directory = (Directory) directories.next();
060                extractDirectoryData(container, directory);
061            }
062        }
063    
064        /**
065         * Extract data from the given metadata directory (like EXIF, IPTC)
066         */
067        private void extractDirectoryData(Element xData, Directory directory) {
068            try {
069                Element xDirectory = new Element("directory");
070                xData.addContent(xDirectory);
071                String dirName = directory.getName();
072                if (dirName != null)
073                    xDirectory.setAttribute("name", dirName);
074                Iterator tags = directory.getTagIterator();
075                while (tags.hasNext()) {
076                    Tag tag = (Tag) tags.next();
077                    extractTagData(xDirectory, tag);
078                }
079            } catch (Exception ex) {
080                LOGGER.debug(ex.getClass().getName() + ": " + ex.getLocalizedMessage());
081            }
082        }
083    
084        /**
085         * Extract data of a single metadata tag
086         */
087        private void extractTagData(Element xDirectory, Tag tag) {
088            try {
089                Element xTag = new Element("tag");
090                xTag.setAttribute("name", tag.getTagName());
091                xTag.setText(tag.getDescription());
092                xDirectory.addContent(xTag);
093            } catch (Exception ex) {
094                LOGGER.debug(ex.getClass().getName() + ": " + ex.getLocalizedMessage());
095            }
096        }
097    
098        /**
099         * Test application that outputs extracted metadata for a given local file.
100         * 
101         * @param args
102         *            the path to a locally stored JPEG file
103         */
104        public static void main(String[] args) {
105            new MCRDataExtractorJPEG().testLocalFile(args[0]);
106        }
107    }