java - 使用Spring Webclient下载文件，文件为空

Question

我应该从第 3 方 API 下载 ZIP 文件。但是，当我使用 Spring Webclient 时，我最终得到了一个空文件。任何想法我做错了什么？存储Flux<DataBuffer>内容的正确方法是什么？到一个文件？
这是我的代码:

WebClient client = WebClient.builder()
            .clientConnector(new ReactorClientHttpConnector(httpClient1))
            .baseUrl(String.format(FILE_DOWNLOAD_PATH))
            .build();


    WebClient.RequestBodyUriSpec method = client.method(HttpMethod.GET);
    method.header("Authorization", "Bearer " + accessToken);
    final Flux<DataBuffer> dataBufferFlux = method.retrieve().bodyToFlux(DataBuffer.class);

    final Path path = FileSystems.getDefault().getPath("example" + new Random(200).nextInt() + ".zip");

    WritableByteChannel channel = Files.newByteChannel(path, StandardOpenOption.CREATE_NEW, StandardOpenOption.WRITE);
    Mono<Path> then = DataBufferUtils.write(dataBufferFlux, channel)
            .map(DataBufferUtils::release)
            .then(Mono.just(path));

更新:上面的代码是直接从 main 调用的，然后应用程序关闭。这可能是一个问题吗？

Answer 1

正如@MichaelBerry 提到的，您错过了 block称呼。
method documentation中明确提到了那:Note that the writing process does not start until the returned Flux is subscribed to.下面的代码对我有用:

public class MySpringBootApp {

  public static void main(String[] args) throws IOException {

    Path path = Paths.get("src/main/resources/sample.zip");
    WebClient client = WebClient.builder()
        .baseUrl("https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-zip-file.zip")
        .build();
    Flux<DataBuffer> dataBufferFlux = client.get().retrieve().bodyToFlux(DataBuffer.class);
    DataBufferUtils.write(dataBufferFlux, path, StandardOpenOption.CREATE).block(); //Creates new file or overwrites exisiting file

  }


}