Learning RxJava

throttleLast() / sample()

The throttleLast() operator (which is aliased as sample()) will only emit the last item at a fixed time interval. Modify your earlier example to use throttleLast() at 1-second intervals, as shown here:

Observable.concat(source1, source2, source3)         .throttleLast(1, TimeUnit.SECONDS)         .subscribe(System.out::println);

The output is as follows:

SOURCE 1: 900SOURCE 2: 900SOURCE 3: 2000

If you study the output, you can see that the last emission at every 1-second interval was all that got through. This effectively samples emissions by dipping into the stream on a timer and pulling out the latest one.

If you want to throttle more liberally at larger time intervals, you will get fewer emissions as this effectively reduces ...