code: public void createSymbolicLink(String link_target, String link_name)
          throws IOException, ServerException {
  
          String arguments = link_target.replaceAll(" ", "%20") + " " + link_name;
          Command cmd = new Command("SITE SYMLINK", arguments);
  
          try {
              controlChannel.execute(cmd);
          }catch (UnexpectedReplyCodeException urce) {
              throw ServerException.embedUnexpectedReplyCodeException(urce);
          } catch (FTPReplyParseException rpe) {
              throw ServerException.embedFTPReplyParseException(rpe);
          }
      }
docs: Create a symbolic link on the FTP server.
  
  @param link_target the path to which the symbolic link should point
  @param link_name the path of the symbolic link to create
  @throws IOException
  @throws ServerException if an error occurred.