de.uni_siegen.wineme.come_in.thumbnailer.util.TemporaryFilesManager.java Source code

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Here is the source code for de.uni_siegen.wineme.come_in.thumbnailer.util.TemporaryFilesManager.java

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/*
 * regain/Thumbnailer - A file search engine providing plenty of formats (Plugin)
 * Copyright (C) 2012  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;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;

/**
 * Keep a list of temporary files so that the same file needn't be copied twice.
 */
public class TemporaryFilesManager {
    private HashMap<File, File> files = new HashMap<File, File>();

    /**
     * Create a new, read-only temporary file.
     * 
     * @param file         Original file that you need a copy of
     * @param newExtension   The extension that the new file should have
     * @return File (read-only) 
     * @throws IOException
     */
    public File createTempfileCopy(File file, String newExtension) throws IOException {
        File destFile = files.get(file);
        if (destFile == null) {
            destFile = File.createTempFile("temp", "." + newExtension);
            createNewCopy(file, destFile);
            destFile.setWritable(false, false);
        } else {
            String newFilename = FilenameUtils.removeExtension(destFile.getAbsolutePath()) + "." + newExtension;
            File newFile = new File(newFilename);
            boolean renameSucces = destFile.renameTo(newFile);
            if (!renameSucces) {
                createNewCopy(file, newFile);
            }
            files.put(file, newFile);
            destFile = newFile;
        }
        return destFile;
    }

    private void createNewCopy(File file, File destFile) throws IOException {
        FileUtils.copyFile(file, destFile);
        files.put(file, destFile);
    }

    /**
     * Delete all registered temporary files
     */
    public void deleteAllTempfiles() {
        for (File destFile : files.values()) {
            IOUtil.deleteQuietlyForce(destFile);
        }
    }
}