Spring Boot 2 Reactor Flux API的Angular客户端(Angular client of Spring Boot 2 Reactor Flux API)

 如何为Java Project Reactor反应性Flux API创建Angular 4客户端？ 下面的示例有两个API： Mono API; 和， Flux API。 两者都是curl ; 但在Angular 4（4.1.2）中，只有Mono API有效; 任何想法如何让Angular 4与Flux API一起使用？ 
 
 这是一个简单的Spring Boot 2.0.0-SNAPSHOT应用程序，带有Mono API和Flux API： 
 
@SpringBootApplication
@RestController
public class ReactiveServiceApplication {

    @CrossOrigin
    @GetMapping("/events/{id}")
    public Mono<Event> eventById(@PathVariable long id) {
        return Mono.just(new Event(id, LocalDate.now()));
    }

    @CrossOrigin
    @GetMapping(value = "/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<Event> events() {
        Flux<Event> eventFlux = Flux.fromStream(
            Stream.generate(
                ()->new Event(System.currentTimeMillis(), LocalDate.now()))
            );

        Flux<Long> durationFlux = Flux.interval(Duration.ofSeconds(1));

        return Flux.zip(eventFlux, durationFlux).map(Tuple2::getT1);
    }

    public static void main(String[] args) {
        SpringApplication.run(ReactiveServiceApplication.class);
    }
}
 
 使用Lombok编辑的活动： 
 
@Data
@AllArgsConstructor
public class Event {
    private final long id;
    private final LocalDate when;
}
 
 正如我所期望的那样，这些反应性API在curl中起作用： 
 
jan@linux-6o1s:~/src> curl -s http://localhost:8080/events/123
{"id":123,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}
 
 类似地，对于非终止的Flux API： 
 
jan@linux-6o1s:~/src> curl -s http://localhost:8080/events
data:{"id":1494887783347,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

data:{"id":1494887784348,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

data:{"id":1494887785347,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

...
 
 使用RxJS的同样微不足道的Angular 4客户端： 
 
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent  implements OnInit, OnDestroy {
  title = 'app works!';
  event: Observable<Event>;
  subscription: Subscription;

  constructor(
    private _http: Http
    ) {
  }

  ngOnInit() {
    this.subscription = this._http
      .get("http://localhost:8080/events/322")
      .map(response => response.json())
      .subscribe(
        e => { 
          this.event = e;
        }
      );
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}
 
 适用于Mono API： 
 
"http://localhost:8080/events/322"
 
 但是Flux API： 
 
"http://localhost:8080/events"
 
 永远不会触发事件处理程序，与curl不同。 

How do I create an Angular 4 client for a Java Project Reactor reactive Flux API? The sample below has two APIs: a Mono API; and, Flux API. Both work from curl; but in Angular 4 (4.1.2) only the Mono API works; any ideas how to get Angular 4 to work with the Flux API?
 
Here's a trivial Spring Boot 2.0.0-SNAPSHOT application with a Mono API and a Flux API:
 
@SpringBootApplication
@RestController
public class ReactiveServiceApplication {

    @CrossOrigin
    @GetMapping("/events/{id}")
    public Mono<Event> eventById(@PathVariable long id) {
        return Mono.just(new Event(id, LocalDate.now()));
    }

    @CrossOrigin
    @GetMapping(value = "/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<Event> events() {
        Flux<Event> eventFlux = Flux.fromStream(
            Stream.generate(
                ()->new Event(System.currentTimeMillis(), LocalDate.now()))
            );

        Flux<Long> durationFlux = Flux.interval(Duration.ofSeconds(1));

        return Flux.zip(eventFlux, durationFlux).map(Tuple2::getT1);
    }

    public static void main(String[] args) {
        SpringApplication.run(ReactiveServiceApplication.class);
    }
}
 
with a Lombok-ed event:
 
@Data
@AllArgsConstructor
public class Event {
    private final long id;
    private final LocalDate when;
}
 
These reactive APIs work from curl as I'd expect:
 
jan@linux-6o1s:~/src> curl -s http://localhost:8080/events/123
{"id":123,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}
 
and similarly for the non-terminating Flux API:
 
jan@linux-6o1s:~/src> curl -s http://localhost:8080/events
data:{"id":1494887783347,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

data:{"id":1494887784348,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

data:{"id":1494887785347,"when":{"year":2017,"month":"MAY","monthValue":5,"dayOfMonth":15,"dayOfWeek":"MONDAY","era":"CE","dayOfYear":135,"leapYear":false,"chronology":{"calendarType":"iso8601","id":"ISO"}}}

...
 
The similarly trivial Angular 4 client with RxJS:
 
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent  implements OnInit, OnDestroy {
  title = 'app works!';
  event: Observable<Event>;
  subscription: Subscription;

  constructor(
    private _http: Http
    ) {
  }

  ngOnInit() {
    this.subscription = this._http
      .get("http://localhost:8080/events/322")
      .map(response => response.json())
      .subscribe(
        e => { 
          this.event = e;
        }
      );
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}
 
works fine for the Mono API:
 
"http://localhost:8080/events/322"
 
but the Flux API:
 
"http://localhost:8080/events"
 
never triggers the event handler, unlike curl.

原文：https://stackoverflow.com/questions/43989889