NullPointerException NullPointerException - 18 days ago 5
Android Question

Problems using SharedPreferences on a Service (getPreferences doesn't exist on a service)

I have some shared preferences (latitude, longitude) that I want to access from a service, that is not subclassed from Activity.

In particular, when I try to access getPreferences, this function doesn't exist's on a service. My code is posted below

My goal here is to allow WRITE these shared preferences with my service. Any suggestions/examples that can help me along?

public class MyService extends Service implements Runnable {

LocationManager mLocationManager;
Location mLocation;
MyLocationListener mLocationListener;
Location currentLocation = null;
static SharedPreferences settings;
static SharedPreferences.Editor configEditor;

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

public void onCreate() {
settings = this.getPreferences(MODE_WORLD_WRITEABLE);
configEditor = settings.edit();
writeSignalGPS();
}

private void setCurrentLocation(Location loc) {
currentLocation = loc;
}

private void writeSignalGPS() {
Thread thread = new Thread(this);
thread.start();
}

@Override
public void run() {
mLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
if (mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Looper.prepare();
mLocationListener = new MyLocationListener();
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 0, mLocationListener);
Looper.loop();
//Looper.myLooper().quit();
} else {
Toast.makeText(getBaseContext(),
getResources().getString(R.string.gps_signal_not_found),
Toast.LENGTH_LONG).show();
}
}

private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (currentLocation!=null) {
configEditor.putString("mylatitude", ""+currentLocation.getLatitude());
configEditor.putString("mylongitude", ""+currentLocation.getLongitude());
configEditor.commit();
}
}
};

private class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location loc) {
if (loc != null) {
Toast.makeText(getBaseContext(),
getResources().getString(R.string.gps_signal_found),
Toast.LENGTH_LONG).show();
setCurrentLocation(loc);
handler.sendEmptyMessage(0);
}
}

@Override
public void onProviderDisabled(String provider) {}

@Override
public void onProviderEnabled(String provider) {}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}


I get the error on the line
settings = this.getPreferences(MODE_WORLD_WRITEABLE);

Answer

If you are only using one SharedPreferences for your application, have all your code get it via PreferenceManager.getDefaultSharedPreferences().