system.reactive - empty observable subscribed, but onNext not called? - Stack Overflow

system.reactive - empty observable subscribed, but onNext not called? - Stack Overflow

You can use Observable.just(null) or any value since you are going to ingore the value anyway. However, it appears you want to perform additional work when values travel through an observable sequence, so you can use doOnNext():

Observable.range(1, 10)  .doOnNext(v -> Log.d("onNext called"))  .map(v -> v * v)  .subscribe(System.out::println);

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