Schedulers and Publishers

For some heavy computations, we may want to run them in the background, while rendering the result in a separate thread so as not to block the UI or rendering thread. For this case, we can use the observeOn method with a different Scheduler.

public static void runComputation() throws Exception {
   StringBuffer sb = new StringBuffer();
   Flowable<String> source = Flowable.fromCallable(() -> { //1
      Thread.sleep(1000); // imitate expensive computation
      return "Done";
   });
source.doOnComplete(() -> System.out.println("Completed runComputation"));

Flowable<String> background = source.subscribeOn(Schedulers.io()); //2

Flowable<String> foreground = background.observeOn(Schedulers.single());//3

foreground.subscribe(System.out::println, Throwable::printStackTrace);//4
}

1. Create a new Flowable from a

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