java并发之awaitTermination的使用

Java

public static ExecutorService executorService = Executors.newFixedThreadPool(10);
    public static void main(String[] args) throws InterruptedException {
        executorService.submit(() -> System.out.println(Thread.currentThread().getName()));
        long curTime = System.currentTimeMillis();
        boolean b = executorService.awaitTermination(3, TimeUnit.SECONDS);
        long lastTime = System.currentTimeMillis();
        System.out.println("duration:" + (lastTime - curTime) + "    result:" + b);
    }

pool-1-thread-1
duration:3004    result:false

public static ExecutorService executorService = Executors.newFixedThreadPool(10);
    public static void main(String[] args) throws InterruptedException {
        executorService.submit(() -> System.out.println(Thread.currentThread().getName()));
        executorService.shutdown();
        long curTime = System.currentTimeMillis();
        boolean b = executorService.awaitTermination(3, TimeUnit.SECONDS);
        long lastTime = System.currentTimeMillis();
        System.out.println("duration:" + (lastTime - curTime) + "    result:" + b);
    }

pool-1-thread-1
duration:0    result:true

public static ExecutorService executorService = Executors.newFixedThreadPool(10);
    public static void main(String[] args) throws InterruptedException {
        executorService.submit(() -> System.out.println(Thread.currentThread().getName()));
        new Thread(() -> {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            executorService.shutdown();
        }).start();
        long curTime = System.currentTimeMillis();
        boolean b = executorService.awaitTermination(3, TimeUnit.SECONDS);
        long lastTime = System.currentTimeMillis();
        System.out.println("duration:" + (lastTime - curTime) + "    result:" + b);
    }

pool-1-thread-1
duration:1004    result:true