从搜索到的本地文件中检索元数据

Question

我正在尝试在将发布在内部办公室网站上的本地文件夹中查找pdf文件的最后修改日期。我的Last_Modified变量返回“ null”

是否可以将修改的日期添加到我创建的Last_Modified变量中？我其余的代码可用于解析文件名。

$.ajax({
    //This will retrieve the contents of the folder if the folder is configured as 'browsable'
    url: url_location,
    success: function (data, textStatus, request) {

        $(data).find("a:contains(.pdf)").each(function () {

            var Last_Modified = request.getResponseHeader("Last-Modified");
            var Link = this.href.split("/")[4];
            Notice_Number = Link.split("_", 1);
            var Category = Link.split("_", 2).slice(1)
            var Subject = Link.split('_').slice(2).join(' ').replace(".pdf", "");

            if (allcookies.indexOf(Notice_Number) != -1) {
                //if cookie is set
                Read_Status = "read";
            } else {
                Read_Status = "unread";
            }
        });
    }
});