在哪里停止/销毁Android服务类中的线程？

public class MyService extends Service {
    private boolean isRunning = true;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (isRunning) {
                    // 执行任务
                }
            }
        }).start();

        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        isRunning = false;
        super.onDestroy();
    }
}

public class MyService extends Service {
    private Handler handler;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                Looper.prepare();
                handler = new Handler() {
                    @Override
                    public void handleMessage(Message msg) {
                        // 处理消息，结束线程
                    }
                };
                Looper.loop();
            }
        }).start();

        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        if (handler != null) {
            handler.sendEmptyMessage(0);
        }
        super.onDestroy();
    }
}