hash 工具類

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);
        }
    }
}