序

本文主要讲述一下spring webflux的文件上传和下载。

maven

                
     
      org.springframework.boot
                 
     
      spring-boot-starter-webflux
             
    

文件上传

@PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)    public Mono
    
      requestBodyFlux(@RequestPart("file") FilePart filePart) throws IOException {        System.out.println(filePart.filename());        Path tempFile = Files.createTempFile("test", filePart.filename());        //NOTE 方法一        AsynchronousFileChannel channel =                AsynchronousFileChannel.open(tempFile, StandardOpenOption.WRITE);        DataBufferUtils.write(filePart.content(), channel, 0)                .doOnComplete(() -> {                    System.out.println("finish");                })            .subscribe();        //NOTE 方法二//        filePart.transferTo(tempFile.toFile());        System.out.println(tempFile.toString());        return Mono.just(filePart.filename());    }
    

使用RequestPart来接收，得到的是FilePart

FilePart的content是Flux<DataBuffer>，可以使用DataBufferUtils写到文件

或者直接使用transferTo写入到文件

文件下载

@GetMapping("/download")    public Mono
    
      downloadByWriteWith(ServerHttpResponse response) throws IOException {        ZeroCopyHttpOutputMessage zeroCopyResponse = (ZeroCopyHttpOutputMessage) response;        response.getHeaders().set(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=parallel.png");        response.getHeaders().setContentType(MediaType.IMAGE_PNG);        Resource resource = new ClassPathResource("parallel.png");        File file = resource.getFile();        return zeroCopyResponse.writeWith(file, 0, file.length());    }
    

这里将数据写入ServerHttpResponse

小结

使用webflux就没有之前基于servlet容器的HttpServletRequest及HttpServletReponse了，取而代之的是org.springframework.http.server.reactive.ServerHttpRequest以及org.springframework.http.server.reactive.ServerHttpResponse。

doc