Thread t1 = new Thread(new Runnable() {
                public void run() {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(Thread.currentThread().getName() + " run 1");
                }
            }, "T1");
             Thread t2 = new Thread(new Runnable() {
                public void run() {
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(Thread.currentThread().getName() + " run 2");
                }
            }, "T2");
             Thread t3 = new Thread(new Runnable() {
                public void run() {
                    try {
                        Thread.sleep(3000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(Thread.currentThread().getName() + " run 3");
                }
            }, "T3");

            //三個執行緒順序執行 第一種方案，單個執行緒池 順序放入執行佇列中
            ExecutorService executor = Executors.newSingleThreadExecutor();

            executor.submit(t3);
            executor.submit(t2);
            executor.submit(t1);
            executor.shutdown();
            //輸出結果如下：
//            pool-1-thread-1 run 3
//            pool-1-thread-1 run 2
//            pool-1-thread-1 run 1