code: public static boolean isAjaxRequest(HttpServletRequest request) {
          String ajaxHeader = request.getHeader("X-Requested-With");
          return StringUtils.isNotBlank(ajaxHeader) && "XMLHttpRequest".equalsIgnoreCase(ajaxHeader);
      }
docs: 判断一个请求是否是Ajax请求
  
  @param request Http请求
  @return 是Ajax请求返回true, 否则返回false