# Runnable接口改進排隊叫號 接下來通過Runnable實現一下我們之前的排隊叫號感受一下 ```java /** * @program: ThreadDemo * @description: 銀行大廳 * @author: hs96.cn@Gmail.com * @create: 2020-08-28 */ public class BankRunnable { public static void main(String[] args) { //一個runnable實例被多個線程共享 TicketWindowRunnable ticketWindow = new TicketWindowRunnable(); Thread windowThread1 = new Thread(ticketWindow, "一號窗口"); Thread windowThread2 = new Thread(ticketWindow, "二號窗口"); Thread windowThread3 = new Thread(ticketWindow, "三號窗口"); windowThread1.start(); windowThread2.start(); windowThread3.start(); } } ``` ```java /** * @program: ThreadDemo * @description: 柜臺，業務處理窗口。繼承Runnable接口 * @author: hs96.cn@Gmail.com * @create: 2020-08-28 */ public class TicketWindowRunnable implements Runnable { private int index = 1; private static final int MAX = 50; @Override public void run() { while (index <= MAX) { System.out.println(Thread.currentThread().getName() + " 的號碼是：" + (index++)); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } } } } ``` 可以看到 index沒有被static修飾，一個runnable實例被多個線程共享了，運行效果如下：  能達到我們的目的，但是這種寫法更加好，線程的邏輯全封裝到一個實例中，所以這也是Runnable存在的必要性。