Office2007FileIdentifier.java

/*
 * regain/Thumbnailer - A file search engine providing plenty of formats (Plugin)
 * Copyright (C) 2011  Come_IN Computerclubs (University of Siegen)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact: Come_IN-Team <come_in-team@listserv.uni-siegen.de>
 */

package de.uni_siegen.wineme.come_in.thumbnailer.util.mime;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;

import de.uni_siegen.wineme.come_in.thumbnailer.util.IOUtil;

/**
 * Add detection of Office2007 files (and OpenOffice files).
 * Magic numbers don't help here, only introspection of the zip.
 */
public class Office2007FileIdentifier implements MimeTypeIdentifier {
	
	@Override
	public String identify(String mimeType, byte[] bytes, File file) {
		if (mimeType == null || mimeType.equals("application/zip") || mimeType.startsWith("application/vnd."))
		{
			ZipFile zipFile = null;
			ZipEntry entry = null;
			try {
				 zipFile = new ZipFile(file);
			 
				 entry = zipFile.getEntry("word/document.xml");
				 if (entry != null)
					 return "application/vnd.openxmlformats-officedocument.wordprocessingml";
				 
				 entry = zipFile.getEntry("ppt/presentation.xml");
				 if (entry != null)
					 return "application/vnd.openxmlformats-officedocument.presentationml";
				 
				 entry = zipFile.getEntry("xl/workbook.xml");
				 if (entry != null)
					 return "application/vnd.openxmlformats-officedocument.spreadsheetml";
				 
				 entry = zipFile.getEntry("mimetype");
				 if (entry != null)
					 return detectOpenOfficeMimeType(zipFile.getInputStream(entry));
			} catch (ZipException e) {
				return mimeType; // Zip file damaged or whatever. Silently give up. 
			} catch (IOException e) {
				return mimeType; // Zip file damaged or whatever. Silently give up. 
			} finally {
				IOUtil.quietlyClose(zipFile);
			}
		}
		
		return mimeType;

	}
	
	private String detectOpenOfficeMimeType(InputStream inputStream) throws IOException
	{
		try {
			BufferedReader in = new BufferedReader(new InputStreamReader(inputStream));
			return in.readLine();
		} finally {
			IOUtil.quietlyClose(inputStream);
		}
	}

	@Override
	public List<String> getExtensionsFor(String mimeType) {
		return null; // I don't know - Aperture knows better than me.
	}
}