• a 标签链接

<a href='文件地址'>下载文件</a>

• 指定location的href

window.location.href = "文件地址";

• window.open()

window.open("文件地址");

• 动态添加a标签

const a = document.createElement('a');
a.href = '文件地址';
a.download = '文件名';
a.click();

• blob类型下载（支持跨域）

const xhr = new XMLHttpRequest();
let url = '';    //接口地址
xhr.open('GET', url, true);
xhr.responseType = 'blob';
xhr.onload = function() {
    var blob = this.response;
    if(blob.type == "text/html"){
	return false;
    }
		
    if(window.navigator.msSaveOrOpenBlob){            // IE浏览器下
	navigator.msSaveBlob(blob, '文件名称');
    } else {
	var  link = document.createElement("a");
	link.href = window.URL.createObjectURL(blob);
	link.download = fileName+suffix;
	link.click();
	window.URL.revokeObjectURL(link.href);
    }
};
xhr.send();