hash 工具类费脑子的博客-

 public class Hash {     private Hash() { }      /**      * Keccak-256 hash function.      *      * @param hexInput hex encoded input data with optional 0x prefix      * @return hash value as hex encoded string      */     public static String sha3(String hexInput) {         byte[] bytes = Numeric.hexStringToByteArray(hexInput);         byte[] result = sha3(bytes);         return Numeric.toHexString(result);     }      public static String sha3String(byte[] input) {          return DigestUtils.sha256Hex(input);     }      /**      * Keccak-256 hash function.      *      * @param input binary encoded input data      * @param offset of start of data      * @param length of data      * @return hash value      */     public static byte[] sha3(byte[] input, int offset, int length) {         Keccak.DigestKeccak kecc = new Keccak.Digest256();         kecc.update(input, offset, length);         return kecc.digest();     }      /**      * Keccak-256 hash function.      *      * @param input binary encoded input data      * @return hash value      */     public static byte[] sha3(byte[] input) {         return sha3(input, 0, input.length);     }      /**      * Keccak-256 hash function that operates on a UTF-8 encoded String.      *      * @param utf8String UTF-8 encoded string      * @return hash value as hex encoded string      */     public static String sha3String(String utf8String) {         return Numeric.toHexString(sha3(utf8String.getBytes(StandardCharsets.UTF_8)));     }      /**      * Generates SHA-256 digest for the given {@code input}.      *      * @param input The input to digest      * @return The hash value for the given input      * @throws RuntimeException If we couldn't find any SHA-256 provider      */     public static byte[] sha256(byte[] input) {         try {             MessageDigest digest = MessageDigest.getInstance("SHA-256");             return digest.digest(input);         } catch (NoSuchAlgorithmException e) {             throw new RuntimeException("Couldn't find a SHA-256 provider", e);         }     } }