RxJava delay for each item of list emitted

Question

I\'m struggling to implement something I assumed would be fairly simple in Rx.

I have a list of items, and I want to have each item emitted with a delay.

It

Answer 1

To delay each group you can change your flatMap() to return an Observable that delays emitting the group.

Observable
        .range(1, 5)
        .groupBy(n -> n % 5)
        .flatMap(g ->
                Observable
                        .timer(50, TimeUnit.MILLISECONDS)
                        .flatMap(t -> g.toList())
        )
        .doOnNext(item -> {
            System.out.println(System.currentTimeMillis() - timeNow);
            System.out.println(item);
            System.out.println(" ");
        }).toList().toBlocking().first();