java - 如何在异步模式下使用 Netflix ObservableResult 和 rxJava

Question

我试图使用 netflix observable 但是我设法只同步地这样做：

这就是我定义远程调用的方式：

@Named
public class BroConsumerService {
..
@HystrixCommand(fallbackMethod = "stubbedMethod")
    public Observable<String> executeObservableBro(String name) {
        return new ObservableResult<String>() {
            @Override
            public String invoke() {
                return executeRemoteService(name);
            }
        };

    } 

 private String stubbedMethod(String name) {
        return "return stubbed";
    }

//这里我实际上是在调用（并观察这个方法）

  @RequestMapping("/executeObservableBro")
    public String executeObservableBro(@RequestParam(value = "name", required = false) String name) throws ExecutionException, InterruptedException {


         Observable<String> result= broConsumerService.executeObservableBro(name);


        result.subscribe(new Observer<String>() {

            @Override
            public void onCompleted() {
                System.out.println("completed");

            }

            @Override
            public void onError(Throwable e) {
                System.out.printf(e.getMessage());

            }

            @Override
            public void onNext(String s) {
                System.out.println("on next..");

            }
        });
    }

但这是同步工作的。我希望能够在执行之前“收听”executeObservableBro。并且每次执行时都会收到通知。

示例将不胜感激。

谢谢，雷。

Answer 1

您必须在 subscribeOn 方法中提供调度程序，例如：

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

    Observable<Integer> observable2 = Observable.create(subscriber->{
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Arrays.asList(1, 2, 3).forEach((value)-> subscriber.onNext(value));
        subscriber.onCompleted();
        subscriber.onError(new RuntimeException("error"));
    });

    System.out.println("Before");

    observable2
            .subscribeOn(Schedulers.io()).subscribe(
                (next) -> log.info("Next element {}", next),
                (error) -> log.error("Got exception", error),
                () -> log.info("Finished")//on complete
    );

    System.out.println("After");
    //Thread.sleep(5000); //uncomment this to wait for subscriptions, otherwise main will quit
}

默认情况下它不是异步的:)