Java

    public static String bytesToHex(byte[] hash) {
        StringBuffer hexString = new StringBuffer();
        for (byte h : hash) {
            String hex = Integer.toHexString(0xff & h);
            if (hex.length() == 1)
                hexString.append('0');
            hexString.append(hex);
        }
        return hexString.toString();
    }
    @Test
    public void test() throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest salt = MessageDigest.getInstance("SHA-256");
        salt.update(UUID.randomUUID().toString().getBytes("UTF-8"));
        String digest = bytesToHex(salt.digest());
        System.out.println(digest);
    }