How to implement polling using Observables?

I’ve got parametrized rest call with Observable interface:

   api.updateAppState(params);

I want to repeat it with delay so I have created delayed version of it:

   Observable<AppState> delayedApiCall = Observable.interval(delay, TimeUnit.SECONDS)
            .first()
            .flatMap(new Func1<Long, Observable<AppState>>() {
        @Override
        public Observable<AppState> call(Long seconds) {
            return lyftApi.updateAppState(params);
        }
    });

But now I want to have polling observable that will recreate “delayedApiCall” with params and produce continuous results. I also want observable to continue producing results even if error was returned in “delayedApiCall”.

    pollingObservable.subscribe(new Observer<AppState>() {
        onNext(AppState appSte) {
           ....
        },
        onError(Throwable e) {
           ....
        }
    });

[akarnokd]

Okay then, how about:

Observable.fromCallable(() -> pollValue())
.repeatWhen(o -> o.concatMap(v -> Observable.timer(20, TimeUnit.SECONDS)));

[akarnokd]

Use Observable.interval() as the starting point and forget that manual recursion.

Observable.interval(1, TimeUnit.SECONDS, Schedulers.io())
.map(time -> pollSource())
.toBlocking()
.subscribe(System.out::println, Throwable::printStackTrace)