private void copyFile(File in, File out) throws IOException {
        FileChannel inChannel = new FileInputStream(in).getChannel();
        FileChannel outChannel = new FileOutputStream(out).getChannel();
        try {
             // magic number for Windows, 64Mb - 32Kb)
            int maxCount = (64 * 1024 * 1024) - (32 * 1024);
            long size = inChannel.size();
            long position = 0;
            while (position < size)
                position += inChannel.transferTo(position, maxCount, outChannel);
        } catch (IOException e) {
            throw e;
        } finally {
            if (inChannel != null) inChannel.close();
            if (outChannel != null) outChannel.close();
        }
    }