public class Demo extends JFrame {
    JLabel label;
    JButton btn;
    String[] nums = {"1", "2", "3", "4", "5"};

    public Demo() {
        setTitle("中獎座位號");
        setBounds(200, 200, 300, 150);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        label = new JLabel("0");//初始值0
        label.setFont(new
 
 Font("宋體", Font.PLAIN, 42));
        label.setHorizontalAlignment(SwingConstants.CENTER);
        getContentPane().add(label, BorderLayout.CENTER);
//label內容隨機變化
        MyThread t = new MyThread();//創建線程對象
        t.start();//啟動線程

        btn = new JButton("暫停");
        getContentPane().add(btn, BorderLayout.SOUTH);
        
 
//按鈕的動作監聽事件
        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String btnName = btn.getText();
                if (btnName.equals("暫停")) {
                    btn.setText("繼續");
                    t.toSuspend();//如果暫停，則線程wait
                } else
 
 {
                    btn.setText("暫停");
                    t.toResume();
                }
            }
        });
        setVisible(true);
    }

    class MyThread extends Thread {//創建線程
        //while循環語句true/false轉換
        private boolean suspend = false;

        public synchronized void toSuspend() {//同步方法
            suspend = true;
        }

        public synchronized void toResume() {
            suspend = false;
            notify();//當前等待的進程，繼續執行（喚醒線程）
        }

        public void run() {//線程執行的內容
            while (true) {
                int randomIndex = new Random().nextInt(nums.length);//隨機索引位置
                String num = nums[randomIndex];
                label.setText(num);//更改label內容
                synchronized (this) {//同步代碼塊
                    while (suspend) {
                        try {
                            wait();//線程進入等待狀態
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        new Demo();
    }
}

線程的暫停與恢復