RxJava; How to emit observables synchronously

Question

I want to synchronously emit two Observable objects (which are asynchronous), one after the other where it returns the first emitted Observable object. If the first

Answer 1

There is no such term as "wait" in reactive programming. You need to think about creating of a data stream, where one Observable could be triggered by another. In your case after receiving token you need to receive account. It could look like this:

Observable accountObservable = Observable.create(new Observable.OnSubscribe() {
    @Override public void call(Subscriber subscriber) {
        subscriber.onNext(new AccessToken());
        subscriber.onCompleted();
    }
}).flatMap(accessToken -> Observable.create(new Observable.OnSubscribe() {
    @Override public void call(Subscriber subscriber) {
        subscriber.onNext(new Account(accessToken));
        subscriber.onCompleted();
    }
}));