js实现通过url下载文本/图片/视频且不跳转新页面

网上无数下载的方法，先挨个试试看好不好用，不好用再用此方法 

        ajax(url, callback, options) {
            window.URL = window.URL || window.webkitURL;
            var xhr = new XMLHttpRequest();
            xhr.open('get', url, true);
            if (options.responseType) {
                xhr.responseType = options.responseType;
            }
            xhr.onreadystatechange = function () {
                if (xhr.readyState === 4 && xhr.status === 200) {
                    callback(xhr);
                }
            };
            xhr.send();
        },
        downloadAjax() {
            let innerurl = this.url;// 文件地址
            var name = this.url.replace(/(.*\/)*([^.]+).*/ig, '$2');
            this.ajax(innerurl, function (xhr) {
                let filename = name + '.' + innerurl.replace(/(.*\.)/, '');
                let content = xhr.response;
                let a = document.createElement('a');
                let blob = new Blob([xhr.response]);
                let url = window.URL.createObjectURL(blob);
                a.href = url;
                a.download = filename;
                a.click();
                window.URL.revokeObjectURL(url);
            }, {
                responseType: 'blob'
            });
        },
        download() {
            if (//是url) {
                this.downloadAjax();
            }
            if (//是下载接口) {
                // 调用接口
                // 携带下载请求参数
                config: {
                    download: true
                }
        }