CompletableFuture 异步调用，获取返回值

 ExecutorService executor = new ThreadPoolExecutor(8, 16, 60,TimeUnit.MINUTES,new ArrayBlockingQueue<>(100));Random random=new Random(10);//模拟查询用户列表List<User> list=selectUsers();//需要执行的任务列表// 任务列表List<CompletableFuture<User>> fList = new ArrayList<>();list.forEach(u->{CompletableFuture<User> f = CompletableFuture.supplyAsync(//异步执行方法//执行耗时较长的业务代码，这里模拟一下()->{//执行完成，设置返回结果 设置 coede 和 listu.setAge(random.nextInt(100));u.setName(UUID.randomUUID().toString());return u;},executor);fList.add(f);});// 阻塞，等待所有任务执行完成CompletableFuture<Void> all= CompletableFuture.allOf(fList.toArray(new CompletableFuture[0]));//因为allOf没有返回值，所以需要通过thenApply回调函数获取结果CompletableFuture<List<User>> allUser=all.thenApply(v-> fList.stream().map(a-> {try {return a.get();} catch (InterruptedException | ExecutionException e) {e.printStackTrace();}return null;}).collect(Collectors.toList()));
//        ---------------获取返回值-----------------try {list=allUser.get();} catch (InterruptedException e) {throw new RuntimeException(e);} catch (ExecutionException e) {throw new RuntimeException(e);}