public static void main(String[] args) throws InterruptedException, ExecutionException {
    //1、thread实现线程
    Thread t1 = new CustomThread.MyThreadDemo();
    t1.start();
    System.out.println(2222);

    //2、利用runnable实现线程
    Thread t2 = new Thread(new MyRunDemo());
    t2.start();


    //3、利用线程池 future callable 实现线程
    FutureTask<String> ft = new FutureTask<String>(new MyCallDemo());
    Executors.newSingleThreadExecutor().execute(ft);
    System.out.println(ft.isDone());
    if (ft.isDone()) {
        System.out.println(ft.get());
    }
    System.out.println(ft.get());
}

public class FutureTest {

    public static void main(String[] args) {
        
        try {
            Calc cal = new Calc();
            System.out.println(cal.call());
            FutureTask<Integer> ft = new FutureTask<>(cal);
            new Thread(() -> {
                try {
                    TimeUnit.SECONDS.sleep(2);
                    ft.run();
                } catch (Exception e1) {
                    System.out.println(e1.getMessage());
                }
            }).start();
            System.out.println(ft.get());
        } catch (Exception e) {
            System.out.println("-------:" + e.getMessage());
        }


    }

    public static class Calc implements Callable<Integer> {

        @Override
        public Integer call() throws Exception {
            return cal(10);
        }

        public static int cal(int num) {
            int sum = 0;
            for (int i = 0; i < num; i++) {
                sum += i;
            }
            return sum;
        }
    }
}