RxJava：合并不同线程上的可观察对象

Question

I need to merge two observables running on different threads. Sample code is

val obs1 = Observable
    .create<Int> { emitter ->
        emitter.onNext(1)
        emitter.onComplete()
    }
    .subscribeOn(Schedulers.newThread())

val obs2 = Observable.just(2)

val obs = Observable
    .just(1, 2)
    .flatMap {
        Observable.merge(
            Observable.just(it).filter { it == 1 }.flatMap { obs1 },
            Observable.just(it).filter { it == 2 }.flatMap { obs2 }
        )
    }
    .serialize()

obs.blockingSubscribe(::println)

Expecting output as 1, 2 , sometime get it 2, 1 .
It seems serialize() doesn't help.
How can I achieve right emission order - 1, 2 ?

Answer 1

Have found proper solution quickly:)

val obs = Observable
    .just(1, 2)
    .concatMap {
        if (it == 1) obs1 else obs2
    }