return (file != null) ? new FileInputStream(file) : null;
GeneralFile file = getFile(bitstream);  return (file != null) ? FileFactory.newFileInputStream(file) : null;
    public static InputStream retrieve(Context context, int id)            throws SQLException, IOException    {        TableRow bitstream = DatabaseManager.find(context, "bitstream", id);        File file = getFile(bitstream);        return (file != null) ? new FileInputStream(file) : null;    }