关于java:FutureTask实现多个线程顺序运行

[问题]

有线程T1,T2,T3,T4 如何实现线程依照T1-T4程序运行?

[代码]

public static void main(String[] args) {    final FutureTask<Integer> ft1 = new FutureTask<>(()-> {        System.out.println("ft1");        return 1;    });    final FutureTask<Integer> ft2 = new FutureTask(()-> {        ft1.get();        System.out.println("ft2");        return 1;    });    final FutureTask<Integer> ft3 = new FutureTask(()-> {        ft2.get();        System.out.println("ft3");        return 1;    });    final FutureTask<Integer> ft4 = new FutureTask(()-> {        ft3.get();        System.out.println("ft4");        return 1;    });    new Thread(ft1).start();    new Thread(ft2).start();    new Thread(ft3).start();    new Thread(ft4).start();}