springboot 返回二进制文件流

    @GetMapping("/getTemplateFile")
    @ApiOperation("数据模板下载")
    public ResponseEntity downFile(HttpServletRequest request) throws IOException {
        File file = new File("C/AA");
        filename = getFilename(request, filename);
        //设置响应头
        HttpHeaders headers = new HttpHeaders();
        //通知浏览器以下载的方式打开文件
        headers.setContentDispositionFormData("attachment", filename);
        //定义以流的形式下载返回文件数据
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        //使用springmvc框架的ResponseEntity对象封装返回数据
        return new ResponseEntity<>(FileUtils.readFileToByteArray(file), headers, HttpStatus.OK);
    }

    
    public String getFilename(HttpServletRequest request, String filename) throws IOException {

        //IE不同版本User-Agent中出现的关键词
        String[] IEBrowserKeyWords = {"MSIE", "Trident", "Edge"};
        //获取请求头代理信息
        String userAgent = request.getHeader("User-Agent");
        for (String keyWord : IEBrowserKeyWords) {
            if (userAgent.contains(keyWord)) {
                //IE内核浏览器，统一为utf-8编码显示
                return URLEncoder.encode(filename, "UTF-8");
            }
        }
        //火狐等其他浏览器统一为ISO-8859-1编码显示
        return new String(filename.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
    }