public static String trimTrailingWhitespace(String str) {
      if (!hasLength(str)) {
         return str;
      }
      StringBuilder sb = new StringBuilder(str);
      while (sb.length() > 0 && Character.isWhitespace(sb.charAt(sb.length() - 1))) {
         sb.deleteCharAt(sb.length() - 1);
      }
      return sb.toString();
   }