废话不多说，直接上代码

Controller

@GetMapping("/download/{file_code}")
public void download(@PathVariable("file_code") String fileCode, 
HttpServletRequest request,HttpServletResponse resp) throws IOException {
        SysFiles model = sysFilesService.selFileByCode(fileCode);// 文件实体
        FileInputStream fis = null;
        try {
            String fileName = model.getFileName() + "." + model.getFileSuffix();
            String filePath = model.getUrl() + "/" + model.getFileCode() + "." +     
                              model.getFileSuffix();
            fis = new FileInputStream(filePath);
            resp.setContentType("application/vnd.ms-excel;charset=UTF-8");
            resp.setCharacterEncoding("UTF-8");
            resp.setHeader("Content-Disposition",
               "attachment;filename=" + java.net.URLEncoder.encode(fileName, "UTF-8"));
            byte[] b = new byte[100];
            int len;
            while ((len = fis.read(b)) > 0) {
                resp.getOutputStream().write(b, 0, len);
            }
        } catch (Exception e) {
            LOGGER.error("文件[ {} ]下载错误", model.getFileName());
        } finally {
            resp.getOutputStream().flush();
            resp.getOutputStream().close();
            fis.close();
        }
    }

view page

download(code, name, suffix) {
    let fileName = name + '.' + suffix;
    this.$ajax.download(baseUrl + 'api/file/download/' + code,{param})// param 为额外参数
        .then((res) =>{
        let data = res.data;
        if(!data){
            return;
        }
        const blob = new Blob([data])
        if(window.navigator.msSaveOrOpenBlob){// 兼容IE10
            navigator.msSaveBlob(blob, fileName);
        }else{// 其他非IE内核支持H5的浏览器
            let url = window.URL.createObjectURL(blob);
            let link = document.createElement('a');
            link.style.display = 'none';
            link.href = url;
            link.setAttribute('download', fileName);
            document.body.appendChild(link);
            link.click()
        })
        .catch((err) =>{
            this.$message.error(err + '');
        })
   },

axios

var download = function(url, data){
	return axios({
		method: 'GET',
		url: url,
		params: data,
		responseType: 'blob',
		headers: {
			'My-Token': VueCookies.get('my-token')
		}
	});
}

按照上面的写就可以实现文件下载

有问题评论区留言吧

==== 这是Q&A分割线=========

Q：文件下载乱码或者通过响应拦截封装axios获取不到data(undefined)

A：1.确保responseType与URL同级，不要写到header里面去。2.确保是data的取值为response.request.response(不封装的前提下可以直接通过response.data获取到)