code: public static String toHex(final byte[] bytes) {
          StringBuilder sb = new StringBuilder();
          for (final byte b : bytes) {
              String s = Integer.toHexString(0xff & b);
  
              if (s.length() < 2) {
                  sb.append("0");
              }
              sb.append(s);
          }
          return sb.toString();
      }
docs: Converts the given byte buffer to a hexadecimal string using {@link java.lang.Integer#toHexString(int)}.
  
  @param bytes the bytes to convert to hex
  @return a String containing the hex representation of the given bytes.