带有明显先后顺序的多线程

烧水泡茶问题
Future类和普通线程
Future相对于普通线程的区别是可以把线程执行的结果传给调用者

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

public class Test3 {


    private static final Callable callable1 = () -> {
        Thread.sleep(3000L); // 模拟烧水动作
        System.out.println("烧开水成功");
        return "hot_water";
    };
    private static final FutureTask ft1 = new FutureTask<>(callable1);
    private static final Callable callable2 = () -> {
        if(ft1.get().equals("hot_water")){
            Thread.sleep(1000L); // 模拟泡茶动作
            System.out.println("泡茶成功");
            return "tea is done";
        }else{
            return "tea is not done";
        }
    };
    private static final FutureTask ft2 = new FutureTask<>(callable2);
    public static void main(String[] args) throws Exception {
        long l = System.currentTimeMillis();
        //Future类
//        Thread thread1 = new Thread(ft1);
//        Thread thread2 = new Thread(ft2);
//        thread1.start();
//        ft1.get();thread1.join();
//        thread2.start();
//        thread2.join();
//        ft2.get();
//常规线程
        Thread t1 = new HotWaterThread();
        Thread t2 = new TeaThread();
        t1.start();
        t1.join();
        t2.start();
        t2.join();
        System.out.println("结束："+(System.currentTimeMillis() - l)/1000);
    }


    private static volatile boolean hot_water = false;

    private static class HotWaterThread extends Thread{
        @Override
        public void run() {
            try{
                Thread.sleep(3000L);
                hot_water = true;
                System.out.println("水已经烧开");
            }catch (InterruptedException e){
                e.printStackTrace();
            }
        }
    }

    private static class TeaThread extends Thread{
        @Override
        public void run() {
            try{
                if(hot_water){
                    Thread.sleep(1000L);
                    System.out.println("茶泡好了");
                }else{
                    System.out.println("没有热水");
                }
            }catch (InterruptedException e){
                e.printStackTrace();
            }
        }
    }
}