[SOLVED] How to get shortest driving path and distance between two geopoint coordinates?

How to get shortest driving path and distance between two geopoint coordinates?

I want to get the road distance between two geopoint coordinates. Currently I am getting the path but it is not very accurate as it considers the start and end of the road but not the curves in the road. I am using the following code:

Double sLat = Double.parseDouble(getIntent().getStringExtra("sLat"));
Double sLon = Double.parseDouble(getIntent().getStringExtra("sLon"));
Double dLat = Double.parseDouble(getIntent().getStringExtra("dLat"));
Double dLon = Double.parseDouble(getIntent().getStringExtra("dLon"));

MapView mv = (MapView) findViewById(R.id.mapview);
mv.setBuiltInZoomControls(true);
MapController mc = mv.getController();
ArrayList<GeoPoint> all_geo_points = getDirections(sLat, sLon, dLat, dLon);
GeoPoint moveTo = (GeoPoint) all_geo_points.get(0);
mc.animateTo(moveTo);
mc.setZoom(18);
mv.getOverlays().add(new MyOverlay(all_geo_points));

    public static ArrayList<GeoPoint> getDirections(double lat1, double lon1, double lat2, double lon2) 
{
    String url = "http://maps.googleapis.com/maps/api/directions/xml?origin=" +lat1 + "," + lon1  + "&destination=" + lat2 + "," + lon2 + "&sensor=false&units=metric";
    String tag[] = { "lat", "lng" };
    ArrayList<GeoPoint> list_of_geopoints = new ArrayList<GeoPoint>();
    HttpResponse response = null;
    try 
    {
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpPost httpPost = new HttpPost(url);
        response = httpClient.execute(httpPost, localContext);
        InputStream in = response.getEntity().getContent();
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = builder.parse(in);
        if (doc != null) {
            NodeList nl1, nl2;
            nl1 = doc.getElementsByTagName(tag[0]);
            nl2 = doc.getElementsByTagName(tag[1]);
            if (nl1.getLength() > 0) {
                list_of_geopoints = new ArrayList<GeoPoint>();
                for (int i = 0; i < nl1.getLength(); i++) {
                     Node node1 = nl1.item(i);
                     Node node2 = nl2.item(i);
                     double lat = Double.parseDouble(node1.getTextContent());
                     double lng = Double.parseDouble(node2.getTextContent());
                     list_of_geopoints.add(new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6)));
                 }
             } else {
                        // No points found
                    }
    }
} 

            catch (Exception e) 
            {
                e.printStackTrace();
            }

            return list_of_geopoints;
        }

        @Override
        protected boolean isRouteDisplayed() {
            // TODO Auto-generated method stub
            return false;
        }

Can anyone give me some ideas how to improve this route and also how to get the distence by road. Currently I am getting crow-fly distance in kilometers but my need is to get distance by road.

Thanks in advance.

Solution