[移动开发]个人 -3月10日 （了解CompletableFuture）

了解ComletableFuture的使用。设想了一个使用场景：
现在一个任务需要多线程执行三个子任务，当三个子任务中如果有一个任务执行出现问题返回false，则其他子任务应当立刻停止。

public class MyTest {
	//首先创建一个线程池，给CompletableFuture使用
	public static final ExecutorService threadPool =
            new ThreadPoolExecutor(20,50,
                    60L, TimeUnit.SECONDS,new ArrayBlockingQueue<>(50),
                    new ThreadPoolExecutor.AbortPolicy());
    public static void main(String[] args) {

        new MyTest().doTestA();
    }


    public void doTestA(){
        CompletableFuture<Void> f1 = CompletableFuture.supplyAsync(() ->{
            System.out.println(Thread.currentThread().getName() + "f1");
            compute(1000000);
            return false;
        },threadPool).thenAccept((result) -> {
            if(!result){
                System.out.println(Thread.currentThread().getName() + "由于f1失败，提前退出");
                threadPool.shutdownNow();
                return;
            }
        });
        CompletableFuture<Void> f2 = CompletableFuture.supplyAsync(() ->{
            System.out.println(Thread.currentThread().getName() + "f2");
            compute(1000000000);
            return true;
        },threadPool).thenAccept((result) -> {
            if(!result){
                System.out.println(Thread.currentThread().getName() + "由于f2失败，提前退出");
            }
        });
        CompletableFuture<Void> f3 = CompletableFuture.supplyAsync(() ->{
            System.out.println(Thread.currentThread().getName() + "f3");
            compute(1000000000);
            return true;
        },threadPool).thenAccept((result) -> {
            if(!result){

                System.out.println(Thread.currentThread().getName() + "由于f3失败，提前退出");
            }
        });
        System.out.println(Thread.currentThread().getName() + "主线程");

    }

    public void doTest(){
        ExecutorService pool = Executors.newCachedThreadPool();

        pool.submit(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println( Thread.currentThread().getName() + " 1 ");
            }
        });
        pool.submit(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println( Thread.currentThread().getName() + " 2 ");
            }
        });
        System.out.println("主线程");
    }


    public void compute(long num){
        List<Integer> list = new ArrayList<>();

        for(int i=0;i<num;i++){
        	//如果此线程被声明为 终止状态，则立即结束计算
            if(!Thread.currentThread().isInterrupted())
                break;
            list.add(new Integer(new Random().nextInt(100000000)));
        }
        Stream<Integer> sorted = list.parallelStream().sorted();
        sorted.collect(Collectors.toList());
    }
}

这段 Demo 的关键就在于