cast String data type to double in Firebase : I'm get data from dataSnapshot Firebase. My data all is String. I can get data but can't cast String to double, if I cast, my app will stop. please help me!

     mReference.addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                String strName=(String) dataSnapshot.child("name").getValue();
                String strphone=(String) dataSnapshot.child("phone").getValue();
                String lati=(String) dataSnapshot.child("latitude").getValue();
                String longti=(String) dataSnapshot.child("longtitude").getValue();
                String strDiemden=(String) dataSnapshot.child("diemden").getValue();
               
              // double lati=Double.parseDouble(strLat);
               // double longti=Double.parseDouble(strLong);
                ;
              mMap.addMarker(new MarkerOptions().position(new LatLng(lati,longti)).title(strName));

