@GetMapping(value = "/file/{fileName}")
public ResponseEntity<FileSystemResource> getFile(@PathVariable("fileName") String fileName) throws FileNotFoundException {
	File file = new File(filePath, fileName);
	if (file.exists()) {
		return export(file);
	}
	System.out.println(file);
	return null;
} 
 
public ResponseEntity<FileSystemResource> export(File file) {
	if (file == null) {
		return null;
	}
	HttpHeaders headers = new HttpHeaders();
	headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
	headers.add("Content-Disposition", "attachment; filename=" + file.getName());
	headers.add("Pragma", "no-cache");
	headers.add("Expires", "0");
	headers.add("Last-Modified", new Date().toString());
	headers.add("ETag", String.valueOf(System.currentTimeMillis()));
	return ResponseEntity.ok().headers(headers).contentLength(file.length()).contentType(MediaType.parseMediaType("application/octet-stream")).body(new FileSystemResource(file));
}
 

    @GetMapping("/getTemplateFile")
    @ApiOperation("數(shù)據(jù)模板下載")
    public ResponseEntity<byte[]> downFile(HttpServletRequest request) throws IOException {
        File file = new File("C/AA");
        filename = getFilename(request, filename);
        //設(shè)置響應(yīng)頭
        HttpHeaders headers = new HttpHeaders();
        //通知瀏覽器以下載的方式打開(kāi)文件
        headers.setContentDispositionFormData("attachment", filename);
        //定義以流的形式下載返回文件數(shù)據(jù)
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        //使用springmvc框架的ResponseEntity對(duì)象封裝返回?cái)?shù)據(jù)
        return new ResponseEntity<>(FileUtils.readFileToByteArray(file), headers, HttpStatus.OK);
    }

    /**
     * 根據(jù)瀏覽器的不同進(jìn)行編碼設(shè)置
     *
     * @param request  請(qǐng)求對(duì)象
     * @param filename 需要轉(zhuǎn)碼的文件名
     * @return 返回編碼后的文件名
     * @throws IOException
     */
    public String getFilename(HttpServletRequest request, String filename) throws IOException {

        //IE不同版本User-Agent中出現(xiàn)的關(guān)鍵詞
        String[] IEBrowserKeyWords = {"MSIE", "Trident", "Edge"};
        //獲取請(qǐng)求頭代理信息
        String userAgent = request.getHeader("User-Agent");
        for (String keyWord : IEBrowserKeyWords) {
            if (userAgent.contains(keyWord)) {
                //IE內(nèi)核瀏覽器，統(tǒng)一為utf-8編碼顯示
                return URLEncoder.encode(filename, "UTF-8");
            }
        }
        //火狐等其他瀏覽器統(tǒng)一為ISO-8859-1編碼顯示
        return new String(filename.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
    }