code: public static String decrypt(String data, byte[] key)
      {
          try
          {
              Key k = toSecretKey(key);
              Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
              cipher.init(Cipher.DECRYPT_MODE, k);
              byte[] toByteArray = Hex.decodeHex(data.toCharArray());
              byte[] decrypted = cipher.doFinal(toByteArray);
              return new String(decrypted, "UTF-8");
          }
          catch (GeneralSecurityException e)
          {
              throw new RuntimeException("Failed to decrypt.", e);
          }
          catch (UnsupportedEncodingException e)
          {
              throw new RuntimeException(e);
          }
          catch (DecoderException e)
          {
              throw new RuntimeException(e);
          }
      }
docs: Decrypt.
  
  @param data the data
  @param key the key
  @return the string