code: public static String decrypt(String key, String hexStr)
      {
          try
          {
              return new String(createAesDecryptionCipher(key).doFinal(ByteUtilities.decode(hexStr)));
          }
          catch (Exception e)
          {
              throw new IllegalStateException("Error occurred decrypting data", e);
          }
      }
docs: Get unencrypted String from encrypted hex String