CompletableFuture<Long> completableFuture = CompletableFuture.supplyAsync(() -> factorial(number));<br /> while (!completableFuture.isDone()) {<br />     System.out.println(“CompletableFuture is not finished yet…”);<br /> }<br /> long result = completableFuture.get();<br />

int number = 20;<br /> Thread newThread = new Thread(() -> {<br />     System.out.println(“Factorial of ” + number + ” is: ” + factorial(number));<br /> });<br /> newThread.start();<br />

ExecutorService threadpool = Executors.newCachedThreadPool();<br /> Future<Long> futureTask = threadpool.submit(() -> factorial(number));<br />  <br /> while (!futureTask.isDone()) {<br />     System.out.println(“FutureTask is not finished yet…”);<br /> }<br /> long result = futureTask.get();<br />  <br /> threadpool.shutdown();<br />