Adding delay between Observable Items RxJava [duplicate]

Question

This question already has answers here: RxJava delay for each item of list emitted (17 answers) Closed 5 years ago. I have an observable I've created from a list of objects. For each object in the list I make a network request but I'd like to put a delay between each item in the list as to space out the requests a bit. Here's a snippet of my code. return Observable.from(documentGroupModels).flatMap(new Func1>() { @Override public Observable call(DocumentGroupModel documentGroupModel) { return refreshDocumentWithUri(documentGroupModel.getUri(), documentGroupModel.sectionGroupId, includeExceptions, false); } }); Using delay or buffer doesn't quite work for this scenario as far as I can tell. JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

You can use a combination of Zip and interval operator if your delay is static, so you can emit an item of your zip every time configure on your interval. Check the example @Test public void delaySteps() { long start = System.currentTimeMillis(); Subscription subscription = Observable.zip(Observable.from(Arrays.asList(1, 2, 3)), Observable.interval(200, TimeUnit.MILLISECONDS), (i, t) -> i) .subscribe(n -> System.out.println("time:" + (System.currentTimeMillis() - start))); new TestSubscriber((Observer) subscription).awaitTerminalEvent(3000, TimeUnit.MILLISECONDS); } Also you can create an Observable with your list and use concatMap, then you can use delay for every item emitted. Maybe this solution is more elegant and no so Hacky @Test public void delayObservableList() { Observable.from(Arrays.asList(1, 2, 3, 4, 5)) .concatMap(s -> Observable.just(s).delay(100, TimeUnit.MILLISECONDS)) .subscribe(n -> System.out.println(n + " emitted"), e -> { }, () -> System.out.println("All emitted")); new TestSubscriber().awaitTerminalEvent(1000, TimeUnit.MILLISECONDS); } You can see another examples of delay here https://github.com/politrons/reactive/blob/master/src/test/java/rx/observables/utils/ObservableDelay.java