docs: public <T> T fromJson(@Nullable String jsonString, JavaType javaType) {
  		if (StringUtils.isEmpty(jsonString)) {
  			return null;
  		}
  
  		try {
  			return (T) mapper.readValue(jsonString, javaType);
  		} catch (IOException e) {
  			logger.warn("parse json string error:" + jsonString, e);
  			return null;
  		}
  	}