code: public static String sha256(String string) throws NoSuchAlgorithmException, UnsupportedEncodingException {
          MessageDigest messageDigest;
          messageDigest = MessageDigest.getInstance("SHA-256");
          byte[] hash = messageDigest.digest(string.getBytes("UTF-8"));
          return String.valueOf(Hex.encodeHex(hash));
      }
docs: SHA-256加密
  
  @param string {@link String}
  
  @return {@link String}
  
  @throws NoSuchAlgorithmException 异常
  @throws UnsupportedEncodingException 异常