private String md5(String data) {
		if (StringUtils.isEmpty(data)) {
			return null;
		}
		if (null == md) {
			try {
				md = MessageDigest.getInstance("MD5");
			}
			catch (NoSuchAlgorithmException ignored) {
				return "unable to get md5";
			}
		}
		return new BigInteger(1, md.digest(data.getBytes(StandardCharsets.UTF_8)))
				.toString(16);
	}
recommend to use
{@link NacosRefreshHistory#addRefreshRecord(java.lang.String, java.lang.String, java.lang.String)}.
@param dataId dataId
@param md5 md5
spring-cloud-alibaba-starters/spring-alibaba-nacos-config/src/main/java/com/alibaba/cloud/nacos/refresh/NacosRefreshHistory.java