我在android studio中遇到了制作计时器的问题

import android.os.Bundle;
import android.os.CountDownTimer;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private TextView timerTextView;
    private CountDownTimer countDownTimer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        timerTextView = findViewById(R.id.timerTextView);

        // 设置计时器总时间为60秒，每隔1秒触发一次onTick()方法
        countDownTimer = new CountDownTimer(60000, 1000) {
            @Override
            public void onTick(long millisUntilFinished) {
                // 更新计时器显示的文本
                timerTextView.setText("剩余时间：" + millisUntilFinished / 1000 + "秒");
            }

            @Override
            public void onFinish() {
                // 计时器结束时执行的操作
                timerTextView.setText("计时器结束");
            }
        };

        // 启动计时器
        countDownTimer.start();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 停止计时器
        countDownTimer.cancel();
    }
}