Spring 5 WebClient仅在.exchange()之后使用.block()时进行Http调用

时间:2018-08-10 03:55:14

标签: spring spring-webflux

此呼叫按预期方式工作,并成功进行了POST:

public class MyService implements IMyService {

private final WebClient webClient;
private final String url;

MyService(@Qualifier("web-client") WebClient webClient,
                      String url) {
    this.webClient = webClient;
    this.url = url;
}

@SneakyThrows
@Override
public void execute(Long jobId) {
    MultiValueMap<String, String> requestParms = new LinkedMultiValueMap<>();
    requestParms.add("arguments", "--batchJobId=" + jobId.toString());
    HttpEntity<MultiValueMap<String, String>> requestEntity =
        new HttpEntity<>(requestParms, null);

    final WebClient.ResponseSpec responseSpec = webClient.post()
        .uri(new URI(url + "/tasks/executions"))
        .body(BodyInserters.fromMultipartData(requestParms))
        .exchange()
        .block();
}
}

在配置类中:

@Bean
@Qualifier("web-client")
public WebClient getWebClient() {
    return WebClient.builder()
        .filter(basicAuthentication("user", "pass"))
        .filter(printLnFilter())
        .build();
}

private ExchangeFilterFunction printLnFilter() {
    return (request, next) -> {
        System.out.println("\n\n" + request.method().toString().toUpperCase() + ":\n\nURL:"
            + request.url().toString() + ":\n\nHeaders:" + request.headers().toString() + "\n\nAttributes:"
            + request.attributes() + "\n\n");

        return next.exchange(request);
    };
}

在上面的示例中,我们看到记录了URL,属性和标头,并且Http调用成功完成。但是,仅删除block()调用将导致不再进行调用,没有日志:

 // No call made
 final WebClient.ResponseSpec responseSpec = webClient.post()
            .uri(new URI(url + "/tasks/executions"))
            .body(BodyInserters.fromMultipartData(requestParms))
            .exchange();

1 个答案:

答案 0 :(得分:3)

那是因为它不受阻碍...

从春季Docs起:

  

简单地说,WebClient是代表主要条目的接口   用于执行Web请求的点。

     

它已被创建为Spring Web Reactive模块的一部分,并且   在这些情况下将取代经典的RestTemplate。新的   客户端是一种反应式,无阻塞的解决方案,可在   HTTP / 1.1协议。

这是通过Reactive Streams实现使用Project Reactor概念的实现