Learning RxJava - Second Edition

blockingLast()

If there is blockingFirst(), it only makes sense to have blockingLast(). This will block and return the last value emitted from an Observable or Flowable source. Of course, it will not return anything until onComplete() is called, so this is something you will want to avoid using with infinite sources.

In the following example, we assert that the last four-character String value emitted from our operation is Zeta:

import io.reactivex.rxjava3.core.Observable;import org.junit.Test;import static org.junit.Assert.assertTrue;public class Ch10_06 {    @Test    public void testLast() {        Observable<String> source =             Observable.just("Alpha", "Beta", "Gamma",                 "Delta", "Zeta");        String lastLengthFour = source.filter(s -> s.length() == 4) .blockingLast() ...