PlayWS - 如何在达到请求超时时抛出异常？

Question

使用 CompletableFuture 使用 PlayWS 执行长时间下载时，有时会达到定义的请求超时。发生这种情况时，PlayWS 似乎不会抛出异常（至少在我的配置中如此），因此下载不会被标记为失败并且会被处理，尽管数据已损坏。

请原谅这种可恶的代码：

final CompletionStage<WSResponse> futureResponse = this.playWS.client
        .url(importSource.getDownloadUrl())
        .setMethod(HttpMethod.GET)
        .setRequestTimeout(Duration.ofSeconds(5)) // When the timeout is reached, the download gets canceled
        .stream();

try {
    futureResponse
            .thenAccept(res -> {
                try (OutputStream outputStream = Files.newOutputStream(file.toPath())) {
                    final Source<ByteString, ?> responseBody = res.getBodyAsSource();
                    final Sink<ByteString, CompletionStage<Done>> outputWriter =
                            Sink.foreach(bytes -> {
                                outputStream.write(bytes.toArray());
                            });
                    responseBody
                            .runWith(outputWriter, this.playWS.materializer)
                            .whenComplete((value, error) -> {
                                System.out.println("VALUE: "+value); // == "Done"
                                System.out.println("Error: "+error); // == null
                            })
                            .exceptionally(exception -> {
                                throw new IllegalStateException("Download failed for: " + importSource.getDownloadUrl(), exception);
                            })
                            .toCompletableFuture().join();
                } catch (final IOException e) {
                    throw new IllegalStateException("Couldn't open or write to OutputStream.", e);
                }
            })
            .exceptionally(exception -> {
                throw new IllegalStateException("Download failed for: " + importSource.getDownloadUrl(), exception);
            })
            .toCompletableFuture().get();
} catch (InterruptedException | ExecutionException e) {
    throw new IllegalStateException("Couldn't complete CompletableFuture.", e);
}

我是不是做错了什么或者这是一个错误？

我看到的唯一解决方案是：

计算接收到的字节数并将它们与 Content-Length header.
将请求超时设置为 -1（无限期）。

感谢任何建议。

Answer 1

我认为有些过于复杂了。

您可以只从 Future 或 CompletableStage 附加到 Source。 Akka Streams API 比 CompletableFuture 更强大（我的意见）

final CompletionStage<WSResponse> futureResponse = this.playWS.client
        .url(importSource.getDownloadUrl())
        .setMethod(HttpMethod.GET)
        .setRequestTimeout(Duration.ofSeconds(5)) 
        .stream();

Source<WSResponse> source = Source.fromCompletableStage(futureResponse);
source.map(...).filter(...).recover(...).runforeach(..., playWS.materializer)

PlayWS - 如何在达到请求超时时抛出异常？

PlayWS - How to throw an exception when Request Timeout is reached?

java

playframework

java-8