code: public static void AssertNotNull(String objName, Object obj) throws ParamException {
          if (obj == null) {
              throw new ParamException(objName + " is null, please check!");
          }
      }
docs: 判断参数是否为NULL，如果为NULL，抛出参数异常
  
  @param objName 参数名
  @param obj 参数对象
  @throws ParamException