Why does my app crash on calling a Service from a Broadcast Receiver on a Button click?

Question

I have developed an app in which a service keeps running in the background. This service is started by a Broadcast Receiver after every 3 minutes. The Broadcast receiver is initiated by a Button click. The problem is that I am getting the following errors when I click the button to start a Broadcast receiver. Can anyone tell me what is going wrong?

My Broadcast Receiver is as follows:

public class k extends BroadcastReceiver{
     public static AlarmManager am;
       @SuppressLint("NewApi")
       @Override
     public void onReceive(Context context, Intent arg1) {
    // TODO Auto-generated method stub
    Intent broadcast = new Intent(context, k.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, broadcast, 0);
    AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,System.currentTimeMillis()+1000, 300000, pendingIntent);
     Intent i = new Intent(context,Ser.class);
     context.getApplicationContext().startService(i);

} }

And my service is as follows:

public class Ser extends Service implements LocationListener {

   public Location getLocation(String provider) {
    if (locationManager.isProviderEnabled(provider)) {
        locationManager.requestLocationUpdates(provider,
                MIN_TIME_FOR_UPDATE, MIN_DISTANCE_FOR_UPDATE, this);
        if (locationManager != null) {
            location = locationManager.getLastKnownLocation(provider);

            double latitude = location.getLatitude();
            double longitude = location.getLongitude();
            String l1=String.valueOf(latitude);
            String l2=String.valueOf(longitude);

        }
    }

    return location;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // TODO Auto-generated method stub

    //Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
    DatabaseHandler db=new DatabaseHandler(getApplicationContext());
    locationManager = (LocationManager) getApplicationContext().getSystemService(LOCATION_SERVICE);
    getLocation(LocationManager.NETWORK_PROVIDER);
    isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

    isNetworkEnabled = locationManager
    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);
    if(isNetworkEnabled==true && isGPSEnabled==false)
    {
        getLocation(LocationManager.NETWORK_PROVIDER);
    }
    else if(isGPSEnabled==true && isNetworkEnabled==false)
    {
        getLocation(LocationManager.GPS_PROVIDER);
    }
    else if(isGPSEnabled==true && isNetworkEnabled==false)
    {
        getLocation(LocationManager.GPS_PROVIDER);
    }
    else if(isGPSEnabled==true && isNetworkEnabled==true )
    {
        getLocation(LocationManager.GPS_PROVIDER);
    }



    return super.onStartCommand(intent, flags, startId);
}
      @Override
   public void onLocationChanged(Location location) {
    this.location=location;
    double latitude =location.getLatitude();
    double longitude = location.getLongitude();
    DatabaseHandler db=new DatabaseHandler(getApplicationContext());
    String l1=String.valueOf(latitude);
    String l2=String.valueOf(longitude);
    val=db.taskid(l1, l2);


}

And here is my error log;

 03-21 16:11:37.515: E/AndroidRuntime(22504): FATAL EXCEPTION: main
 03-21 16:11:37.515: E/AndroidRuntime(22504): java.lang.RuntimeException: Unable to start service com.example.ishutup.Ser@4105d298 with Intent { cmp=com.example.ishutup/.Ser }: java.lang.NullPointerException
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2376)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.app.ActivityThread.access$1900(ActivityThread.java:123)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.os.Handler.dispatchMessage(Handler.java:99)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.os.Looper.loop(Looper.java:137)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.app.ActivityThread.main(ActivityThread.java:4424)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at java.lang.reflect.Method.invokeNative(Native Method)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at java.lang.reflect.Method.invoke(Method.java:511)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at dalvik.system.NativeStart.main(Native Method)
 03-21 16:11:37.515: E/AndroidRuntime(22504): Caused by: java.lang.NullPointerException
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at com.example.ishutup.Ser.getLocation(Ser.java:40)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at com.example.ishutup.Ser.onStartCommand(Ser.java:61)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2359)
 03-21 16:11:37.515: E/AndroidRuntime(22504):   ... 10 more

If you read through the stacktrace, you might notice that a `NullPointerException` is thrown in `onStartCommand` method, referencing `getLocation` method. Maybe your `locationManager` is `null`? — Tadej, Mar 21 '14 at 11:17
location = locationManager.getLastKnownLocation(provider); is line number 40 — anu_r, Mar 21 '14 at 11:17

kstachniuk · Answer 1 · 2014-03-21T11:27:27.183

0

Maybe the location is null.

From the LocationManager.getLastKnownLocation documentation: If the provider is currently disabled, null is returned

edited Mar 21 '14 at 11:27

answered Mar 21 '14 at 11:18

kstachniuk

358
1
4

Can you suggest how to fix it pls? – anu_r Mar 21 '14 at 11:29
try this http://stackoverflow.com/questions/15997079/getlastknownlocation-always-return-null-after-i-re-install-the-apk-file-via-ecli – kstachniuk Mar 21 '14 at 11:31

Why does my app crash on calling a Service from a Broadcast Receiver on a Button click?

1 Answers1