Java Coding Problems

Explicitly complete a CompletableFuture

A CompletableFuture can be explicitly completed using complete​(T value), completeAsync​(Supplier<? extends T> supplier), and completeAsync​(Supplier<? extends T> supplier, Executor executor). T is the value returned by get(). Here it is a method that creates CompletableFuture and returns it immediately. Another thread is responsible for executing some tax computations and completing the CompletableFuture with the corresponding result:

public static CompletableFuture<Integer> taxes() {  CompletableFuture<Integer> completableFuture     = new CompletableFuture<>();  new Thread(() -> {    int result = new Random().nextInt(100);    Thread.sleep(10);    completableFuture.complete(result);  }).start(); return completableFuture; ...