Android后台服务错误：无法在未调用的线程内创建处理程序

Question

这是我的任务： 我需要运行2个后台服务。通过ksoap.another服务将我的移动数据同步到服务器我需要将我的gps位置发送到服务器。 所以我写了这个代码。但是当我添加gpsTimer部分时，它在加载application.please时给出了以下错误帮助我理清这个问题。或者告诉我任何其他方式来实现这个案例。

这是我的代码

public class BackgroundService extends Service {

    private Timer timer;
    private Timer gpsTimer;

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

    public void onCreate() {
        super.onCreate();
        timer = new Timer("BackgroundServiceTimer");
        timer.schedule(syncTask, 1000L, 60 * 1000L);

        gpsTimer = new Timer("GPSServiceTimer");
        gpsTimer.schedule(syncTaskGps, 1000L, 10 * 1000L);

    }

    public void onDestroy() {
        super.onDestroy();
        timer.cancel();
        timer = null;

        gpsTimer.cancel();
        gpsTimer = null;
    }

    public void onLowMemory() {
        super.onLowMemory();
        stopService(new Intent(com.lk.lankabell.android.activity.BackgroundService.class.getName()));

    }

    private TimerTask syncTaskGps = new TimerTask() {
        public void run() {
          Log.w("GPS Tracker", "Tracker going to run"+new Date());
          LocationManager mlocManager =(LocationManager)getSystemService(Context.LOCATION_SERVICE);
          LocationListener mlocListener = new MyLocationListener();
          mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);    
        }
    };
    private TimerTask syncTask = new TimerTask() {
        public void run() {
            if (isOnline() == true) {
                Log.w("Method 2", "setUpdateCardAcceptTag");
                setUpdateCardAcceptTag();
                Log.w("Method 3", "getCardBulkSerialData");
                getCardBulkSerialData();
                Log.w("Method 12", "updateStockDataFromRemote");
                updateStockDataFromRemote();
                Log.w("Method 5", "SetRemarksData");
                SetRemarksData();
                Log.w("Method 6", "SetCardSaleData");
                SetCardSaleData();
                Log.w("Method 7", "synchMerchants");
                synchMerchants();
                Log.w("Method 9", "getUpdatedCities");
                getUpdatedCities();
                Log.w("Method 10", "getNotifications");
                getNotifications();
                Log.w("Method 11", "getNextSerialDetails");
                getNextSerialDetails();
                Log.w("Method 12", "getNextSerialDetails");
                //synchLocations();
                Log.w("Method 13", "synchLocations");

            }
        }
    };

这是错误：

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Answer 1

TimerTask在与UI线程不同的线程上运行，并且根据文档，如果调用线程没有Looper，则抛出RuntimeException。尝试以这种方式更改代码：

private TimerTask syncTaskGps = new TimerTask() {
        public void run() {
          Looper.prepare();
          Log.w("GPS Tracker", "Tracker going to run"+new Date());
          LocationManager mlocManager =(LocationManager)getSystemService(Context.LOCATION_SERVICE);
          LocationListener mlocListener = new MyLocationListener();
          mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener, Looper.getMainLooper()); 
          Looper.loop();   
        }
    };

Answer 2

使用Handler代替Timer / TimerTask

public class MyService extends Service {
private Handler mTimer = new Handler();
private Runnable mTask = new Runnable() {
@Override
public void run() {
//DO SOMETHING HERE
mTimer.postDelayed(this, interval*1000L);
}
};

private int interval = 60; // 60 seconds

public void onCreate() {
mTimer.postDelayed(mTask, interval*1000L); //start the timer for the first time
}

public void onDestroy() {
if(mTimer != null) {
mTimer.removeCallbacks(mTask); //cancel the timer
}
}
}

通过使用Handler，您可以随时重置间隔，例如，首先您希望它每5秒运行一次，而不是用户决定每1秒运行一次，只需更改间隔变量并调用mTimer.postDelayed试。