Question

In my android app i ve a MapView, i ve to show route b/w two points i implemented code but its showing only half route. i tried in many ways but could not resolve it please help where i am doing mistake.here is a screen shot two red points and blue route http://www.flickr.com/photos/77093196@N03/7117948377/
following is the code:

MapdirectionsActivity.java

public class MapdirectionsActivity extends MapActivity {
    /** Called when the activity is first created. */

    MapView mapView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mapView = (MapView) findViewById(R.id.mapview);
        double src_lat = 17.3667; // the source
        double src_long = 78.4667;
        double dest_lat =  18.9647; // the destination
        double dest_long = 72.8258;
        GeoPoint srcGeoPoint = new GeoPoint((int) (src_lat * 1E6),(int) (src_long * 1E6));
        GeoPoint destGeoPoint = new GeoPoint((int) (dest_lat * 1E6),(int) (dest_long * 1E6));
        DrawPath(srcGeoPoint, destGeoPoint, mapView);
        mapView.getController().animateTo(srcGeoPoint);
        mapView.getController().setZoom(7);
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    private void DrawPath(GeoPoint src, GeoPoint dest, MapView mMapView) {

        // connect to map web service
        StringBuilder urlString = new StringBuilder();
        urlString.append("http://maps.google.com/maps?f=d&hl=en");
        urlString.append("&saddr=");// from
        urlString.append(Double.toString((double) src.getLatitudeE6() / 1.0E6));
        urlString.append(",");
        urlString.append(Double.toString((double) src.getLongitudeE6() / 1.0E6));
        urlString.append("&daddr=");// to
        urlString.append(Double.toString((double) dest.getLatitudeE6() / 1.0E6));
        urlString.append(",");
        urlString.append(Double.toString((double) dest.getLongitudeE6() / 1.0E6));
        urlString.append("&ie=UTF8&om=1&output=kml");
        Log.d("Map directions", "URL= " + urlString.toString());

        // get the kml (XML) doc. And parse it to get the coordinates(direction route).
        Document doc = null;
        HttpURLConnection urlConnection = null;
        URL url = null;
        try {
            url = new URL(urlString.toString());
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.connect();

            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = db.parse(urlConnection.getInputStream());

            if (doc.getElementsByTagName("GeometryCollection").getLength() > 0) {
                String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getFirstChild().getNodeValue();
                Log.d("Map directions", "path= " + path);
                String[] pairs = path.split(" ");
                String[] lngLat = pairs[0].split(","); // lngLat[0]=longitude
                                                        // lngLat[1]=latitude
                                                        // lngLat[2]=height
                GeoPoint startGP = new GeoPoint(
                        (int) (Double.parseDouble(lngLat[1]) * 1E6),
                        (int) (Double.parseDouble(lngLat[0]) * 1E6));

                mMapView.getOverlays().add(new MyOverLay(startGP, startGP, 1));//starting point
                GeoPoint gp1 = null;
                GeoPoint gp2 = startGP;
                for (int i = 1; i <pairs.length; i++)
                {
                    lngLat = pairs[i].split(",");
                    gp1 = gp2;
                    // watch out! For GeoPoint, first:latitude, second:longitude
                    gp2 = new GeoPoint(
                            (int) (Double.parseDouble(lngLat[1]) * 1E6),
                            (int) (Double.parseDouble(lngLat[0]) * 1E6));

                    mMapView.getOverlays().add(new MyOverLay(gp1, gp2, 2));//route
                }

                mMapView.getOverlays().add(new MyOverLay(dest, dest, 3));   //last point
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        }
    }
}

MyOverLay.java

public class MyOverLay extends Overlay {
    private GeoPoint gp1;
    private GeoPoint gp2;
    private int mRadius = 6;
    private int mode = 0;

    public MyOverLay(GeoPoint gp1, GeoPoint gp2, int mode) // Constructor
    {
        this.gp1 = gp1;
        this.gp2 = gp2;
        this.mode = mode;
    }

    public int getMode() {
        return mode;
    }

    @Override
    public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
            long when) {

        Projection projection = mapView.getProjection();
        if (shadow == false) {
            Paint paint = new Paint();
            paint.setAntiAlias(true);
            Point point = new Point();
            projection.toPixels(gp1, point);
            // start
            if (mode == 1) {
                paint.setColor(Color.RED);
                RectF oval = new RectF(point.x - mRadius, point.y - mRadius,
                        point.x + mRadius, point.y + mRadius);

                canvas.drawOval(oval, paint);// start point
            }
            // mode=2：path
            else if (mode == 2) {
                paint.setColor(Color.BLUE);
                Point point2 = new Point();
                projection.toPixels(gp2, point2);
                paint.setStrokeWidth(5);
                paint.setAlpha(120);
                canvas.drawLine(point.x, point.y, point2.x, point2.y, paint);// mode=2：path
            }
            /* mode=3：end */
            else if (mode == 3) {
                /* the last path */

                paint.setColor(Color.RED);
                Point point2 = new Point();
                projection.toPixels(gp2, point2);
                paint.setStrokeWidth(5);
                paint.setAlpha(120);
                canvas.drawLine(point.x, point.y, point2.x, point2.y, paint);
                RectF oval = new RectF(point2.x - mRadius, point2.y - mRadius,
                        point2.x + mRadius, point2.y + mRadius);

                paint.setAlpha(255);
                canvas.drawOval(oval, paint);/* end point */
            }
        }
        return super.draw(canvas, mapView, shadow, when);
    }

}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.maps.MapView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/mapview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:apiKey="0E2QBBM0fi1TSN6J0hCLbETO8oscApDt5CDqgbQ"
    android:clickable="true"
    android:enabled="true" />

Answer 1

Refer this link to draw driving path in your application. You just need to add the four classes present in the link in your project and call the below lines when you need to display the route.

SharedData data = SharedData.getInstance();
data.setAPIKEY("0RUTLH7cqd6yrZ0FdS0NfQMO3lioiCbnH-BpNQQ");//set your map key here
data.setSrc_lat(17);//set your src lat
data.setSrc_lng(78);//set your src lng
data.setDest_lat(18);//set your dest lat
data.setDest_lng(77);//set your dest lng
startActivity(new Intent(YourActivity.this,RoutePath.class));//add RoutePath in your manifeast file

//Also add the permission to your manifeast file