This program is to show the use of theRun() method of completablefuture

TestThenRun.java

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

class Test {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<Integer> completableFuture = CompletableFuture.supplyAsync(() -> (int) (Math.random() * 10));
        CompletableFuture<Void> voidCompletableFuture = completableFuture.thenRun(() -> {
            System.out.println("Random number is generated.");
        });
        voidCompletableFuture.get();
    }
}