spring实现文件下载的方法是什么

@GetMapping("/downloadFile")
public ResponseEntity<Resource> downloadFile() {
    Resource resource = new FileSystemResource("path/to/file.txt");
    
    HttpHeaders headers = new HttpHeaders();
    headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=file.txt");
    
    return ResponseEntity
            .ok()
            .headers(headers)
            .contentLength(resource.contentLength())
            .contentType(MediaType.APPLICATION_OCTET_STREAM)
            .body(resource);
}

@GetMapping("/downloadFile")
public void downloadFile(HttpServletResponse response) {
    File file = new File("path/to/file.txt");
    
    response.setContentType(MediaType.APPLICATION_OCTET_STREAM.toString());
    response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=file.txt");
    response.setContentLength((int) file.length());
    
    try (
        InputStream inputStream = new FileInputStream(file);
        OutputStream outputStream = response.getOutputStream();
    ) {
        IOUtils.copy(inputStream, outputStream);
        outputStream.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }
}