Java—線程按順序執行

1.第一種方法：Thread.join()

    public static void main(String[] args) {
        final Thread t1 = new Thread(new Runnable() {

            @Override
            public void run() {
                System.out.println("t1");
            }
        });
        final Thread t2 = new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    t1.join();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("t2");
            }
        });
        Thread t3 = new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    t2.join();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("t3");
            }
        });
        t3.start();
        t2.start();
        t1.start();
    }

2.第二種方法：線程池

    public static void main(String[] args) {
        final Thread t1 = new Thread(new Runnable() {

            @Override
            public void run() {
                System.out.println("t1");
            }
        });
        final Thread t2 = new Thread(new Runnable() {

            @Override
            public void run() {
                System.out.println("t2");
            }
        });
        Thread t3 = new Thread(new Runnable() {

            @Override
            public void run() {
                System.out.println("t3");
            }
        });

        ExecutorService executorService = Executors.newSingleThreadExecutor();
        executorService.submit(t1);
        executorService.submit(t2);
        executorService.submit(t3);
        executorService.shutdown();
    }