Android可靠的精确时间后台操作。

代码示例：

1. 获取当前时间

Calendar calendar = Calendar.getInstance();
Date now = calendar.getTime();

2. 后台实时更新时间

public class TimeService extends Service {
    private Timer timer;

    @Override
    public void onCreate() {
        super.onCreate();
        timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                Calendar calendar = Calendar.getInstance();
                Date now = calendar.getTime();
                // TODO: 将时间更新到数据库或其他需要的地方
            }
        }, 0, 1000);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        timer.cancel();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

3. 启动后台服务

Intent intent = new Intent(this, TimeService.class);
startService(intent);