【Java并发】线程的顺序执行

/**
 * 问题：有线程a、b、c，如何让它们顺序执行？
 * 方式一：可用Join()方法实现
 * 方式二：可用newSingleThreadExecutor()
 * Created by Smile on 2018/8/12.
 */
public class ThreadByOrder {

    public static void main(String[] args) throws InterruptedException {

        Thread a = new Thread(new ThreadTest("a"));
        Thread b = new Thread(new ThreadTest("b"));
        Thread c = new Thread(new ThreadTest("c"));

        //方式一实现
        a.start();
        a.join();
        b.start();
        b.join();
        c.start();

        Thread d = new Thread(new ThreadTest("d"));
        Thread e = new Thread(new ThreadTest("e"));
        Thread f = new Thread(new ThreadTest("f"));
        //方式二实现
        ExecutorService singlePool = Executors.newSingleThreadExecutor();
        singlePool.submit(d);
        singlePool.submit(e);
        singlePool.submit(f);
        singlePool.shutdown();
    }

    static class ThreadTest implements Runnable{

        private String threadName;

        public ThreadTest(String name){
            this.threadName = name;
        }

        public ThreadTest() {
        }

        public void run() {
            if("a".equals(threadName)||"f".equals(threadName))
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            System.out.println("thread "+threadName+" is running...");
        }
    }
}