Spring WebFlux:如何将文件作为字节数组从DB返回

@RestController
public class FileController {

    @Autowired
    private FileRepository fileRepository;

    @GetMapping("/download/{id}")
    public ResponseEntity<byte[]> downloadFile(@PathVariable("id") Long id) {
        // 从数据库中获取文件实体
        FileEntity fileEntity = fileRepository.findById(id).orElse(null);
        
        if (fileEntity != null) {
            // 获取文件的字节数组
            byte[] fileBytes = fileEntity.getFileBytes();
            
            // 构建响应对象，设置响应的内容类型和长度
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            headers.setContentLength(fileBytes.length);
            
            // 返回响应对象
            return new ResponseEntity<>(fileBytes, headers, HttpStatus.OK);
        } else {
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }
}