Js achieve native file downloading and setting a request header header

Js achieve native file downloading and setting a request header header

const token="自行定义";//如果有
/**
* 向指定路径发送下载请求
* @param{String} url 请求路径
*/
function downLoadByUrl(url){
        var xhr = new XMLHttpRequest();
        //GET请求,请求路径url,async(是否异步)
        xhr.open('GET', url, true);
        //设置请求头参数的方式,如果没有可忽略此行代码
        // xhr.setRequestHeader("token", token);
        //设置响应类型为 blob
        xhr.responseType = 'blob';
        //关键部分
        xhr.onload = function (e) {
            //如果请求执行成功
            if (this.status == 200) {
                var blob = this.response;
                var filename = "我是文件名.xxx";//如123.xls
                var a = document.createElement('a');

                blob.type = "application/octet-stream";
                //创键临时url对象
                var url = URL.createObjectURL(blob);

                a.href = url;
                a.download=filename;
                a.click();
                //释放之前创建的URL对象
                window.URL.revokeObjectURL(url);
            }
        };
        //发送请求
        xhr.send();
}