Buffering operator allows to gather items emitted by an Observable into a list or bundles and emit those bundles instead of items. In the example below, we've created an Observable to emit 9 items and using buffering, 3 items will be emitted together.
Create the following Java program using any editor of your choice in, say, C:\> RxJava.
import io.reactivex.Observable; import io.reactivex.Observer; import io.reactivex.disposables.Disposable; import io.reactivex.schedulers.Schedulers; import java.util.List; import java.util.concurrent.TimeUnit; public class ObservableTester { public static void main(String[] args) throws InterruptedException { Observable<Integer> observable = Observable.just(1, 2, 3, 4, 5, 6, 7, 8, 9); observable.subscribeOn(Schedulers.io()) .delay(2, TimeUnit.SECONDS, Schedulers.io()) .buffer(3) .subscribe(new Observer<List<Integer>>() { @Override public void onSubscribe(Disposable d) { System.out.println("Subscribed"); } @Override public void onNext(List<Integer> integers) { System.out.println("onNext: "); for (Integer value : integers) { System.out.println(value); } } @Override public void onError(Throwable e) { System.out.println("Error"); } @Override public void onComplete() { System.out.println("Done! "); } }); Thread.sleep(3000); } }
Compile the class using javac compiler as follows −
C:\RxJava>javac ObservableTester.java
Now run the ObservableTester as follows −
C:\RxJava>java ObservableTester
It should produce the following output −
Subscribed onNext: 1 2 3 onNext: 4 5 6 onNext: 7 8 9 Done!