future.get()会阻塞，感觉这会导致并发多线程变得同步了，因为会在`future.get()`这一步得到结果后再执行

demo如下：

public class FutureDemo {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService service = Executors.newScheduledThreadPool(3);
        for (int i = 0; i < 10; i++) {
            Future<String> submit = service.submit(new Task("" + i));
            System.out.println("Future result: " + submit.get());        }
    }
}