public class FileAes256Util { private static String KEY = "9003e5a13d69a78c0d8210cb28b9d0d38e5445568899f637c24bc08241f98ded"; private static String IV = "024e54561023da13118d16ac21119b8a"; public static byte[] hexStringToByteArray(String s) { int len = s.length(); byte[] data = new byte[len / 2]; for (int i = 0; i < len; i += 2) { data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16)