private static void showServerReply(FTPClient ftpClient) {
   String[] replies = ftpClient.getReplyStrings();
   if (replies != null && replies.length > 0) {
     for (String aReply : replies) {
       System.out.println("SERVER: " + aReply);
     }
   }
 }
  /** Function append smth to remote text file. */
  public void appendFile(String fileName, String appendContent)
      throws SocketException, IOException {

    connect2Server();

    ByteArrayInputStream oInStream = new ByteArrayInputStream((appendContent + "\n").getBytes());

    if (!oFtp.appendFile(fileName, oInStream)) {
      logError(
          "File `"
              + fileName
              + "` can't append. FTP reply code: "
              + oFtp.getReplyCode()
              + " Ftp message: "
              + Arrays.asList(oFtp.getReplyStrings()));
    }

    closeFtpConnection();
  }
  /**
   * Delete file from server
   *
   * @param filename
   * @param ftpFolder
   * @throws SocketException
   * @throws IOException
   */
  public void removeFile(String filename, String ftpFolder) throws SocketException, IOException {
    connect2Server();

    if (oFtp.isConnected()) {
      String file = ftpFolder + filename;

      if (this.isExists(filename, ftpFolder)) {
        if (!oFtp.deleteFile(file)) {
          logError(
              "Can't delete file '"
                  + filename
                  + "' from "
                  + ftpFolder
                  + " FTP reply code: "
                  + oFtp.getReplyCode()
                  + " Ftp message: "
                  + Arrays.asList(oFtp.getReplyStrings()));
        } else {
          logMessage("File '" + file + "' removed from server");
        }
      }
    }
    this.closeFtpConnection();
  }