js 通过url 直接下载文件

function getFileAndDownload(fileName, url) {
    var x = new XMLHttpRequest();
    x.open("GET", url, true);
    x.responseType = 'blob';
    x.onload = function (e) {
        var blob = x.response;
        if ('msSaveOrOpenBlob' in navigator) {//IE导出
            window.navigator.msSaveOrOpenBlob(blob, fileName);
        }
        else {
            var a = document.createElement('a');
            a.download = fileName;
            a.href = URL.createObjectURL(blob);
            $("body").append(a);
            a.click();
            $(a).remove();
        }
    };
    x.send();
}

原文忘了