Drawing a line/path on Google Maps

I've been busy for a long time finding out how to draw a line between two (GPS) points on the map in HelloMapView but with no luck.

Could anyone please tell me how to do so.

Suppose I use the HelloMapView which extends MapView. Do I need to use overlays? If so do I have to override the onDraw() method of the overlay and draw a line here? I actually tried these things but with no result.

Thank you in advance!

Thank you for your help. At last I could draw a line on the map. This is how I done it:

/** Called when the activity is first created. */
private List<Overlay> mapOverlays;

private Projection projection;  

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    
    linearLayout = (LinearLayout) findViewById(R.id.zoomview);
    mapView = (MapView) findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true);
    
    mapOverlays = mapView.getOverlays();        
    projection = mapView.getProjection();
    mapOverlays.add(new MyOverlay());        
   
}

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

class MyOverlay extends Overlay{

	public MyOverlay(){

	} 	

	public void draw(Canvas canvas, MapView mapv, boolean shadow){
		super.draw(canvas, mapv, shadow);

		Paint	mPaint = new Paint();
		mPaint.setDither(true);
		mPaint.setColor(Color.RED);
		mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
		mPaint.setStrokeJoin(Paint.Join.ROUND);
		mPaint.setStrokeCap(Paint.Cap.ROUND);
		mPaint.setStrokeWidth(2);
		
		GeoPoint gP1 = new GeoPoint(19240000,-99120000);
		GeoPoint gP2 = new GeoPoint(37423157, -122085008);
		
		Point p1 = new Point();
		Point p2 = new Point();
		Path path = new Path();
        
        Projection projection=mapv.getProjection();
		projection.toPixels(gP1, p1);
		projection.toPixels(gP2, p2);
		    			
		path.moveTo(p2.x, p2.y);
		path.lineTo(p1.x,p1.y);
		
		canvas.drawPath(path, mPaint);
	}

For those who really only want to draw a simple line - there is indeed also the short short version.

GoogleMap map;
// ... get a map.
// Add a thin red line from London to New York.
Polyline line = map.addPolyline(new PolylineOptions()
    .add(new LatLng(51.5, -0.1), new LatLng(40.7, -74.0))
    .width(5)
    .color(Color.RED));

from https://developers.google.com/maps/documentation/android/reference/com/google/android/gms/maps/model/Polyline

// This Activity will draw a line between two selected points on Map

public class MainActivity extends MapActivity {
 MapView myMapView = null;
 MapController myMC = null;
 GeoPoint geoPoint = null;

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  
  
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  myMapView = (MapView) findViewById(R.id.mapview);
  geoPoint = null;
  myMapView.setSatellite(false);

  String pairs[] = getDirectionData("ahmedabad", "vadodara");
  String[] lngLat = pairs[0].split(",");

  // STARTING POINT
  GeoPoint startGP = new GeoPoint(
    (int) (Double.parseDouble(lngLat[1]) * 1E6), (int) (Double
      .parseDouble(lngLat[0]) * 1E6));

  myMC = myMapView.getController();
  geoPoint = startGP;
  myMC.setCenter(geoPoint);
  myMC.setZoom(15);
  myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));

  // NAVIGATE THE PATH
  
  GeoPoint gp1;
  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));
   myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));
   Log.d("xxx", "pair:" + pairs[i]);
  }

  // END POINT
  myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));

  myMapView.getController().animateTo(startGP);
  myMapView.setBuiltInZoomControls(true);
  myMapView.displayZoomControls(true);

 }

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

 private String[] getDirectionData(String srcPlace, String destPlace) {

  String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="
   + srcPlace + "&daddr=" + destPlace
   + "&ie=UTF8&0&om=0&output=kml";
  
  Log.d("URL", urlString);
  Document doc = null;
  HttpURLConnection urlConnection = null;
  URL url = null;
  String pathConent = "";
  
  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());

  } catch (Exception e) {
  }

  NodeList nl = doc.getElementsByTagName("LineString");
  for (int s = 0; s < nl.getLength(); s++) {
   Node rootNode = nl.item(s);
   NodeList configItems = rootNode.getChildNodes();
   for (int x = 0; x < configItems.getLength(); x++) {
    Node lineStringNode = configItems.item(x);
    NodeList path = lineStringNode.getChildNodes();
    pathConent = path.item(0).getNodeValue();
   }
  }
  String[] tempContent = pathConent.split(" ");
  return tempContent;
 }

}


//*****************************************************************************

DirectionPathOverlay

public class DirectionPathOverlay extends Overlay {
 
    private GeoPoint gp1;
    private GeoPoint gp2;
    
    public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {
        this.gp1 = gp1;
        this.gp2 = gp2;
    }

    @Override
    public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
            long when) {
        // TODO Auto-generated method stub
        Projection projection = mapView.getProjection();
        if (shadow == false) {
         
            Paint paint = new Paint();
            paint.setAntiAlias(true);
            Point point = new Point();
            projection.toPixels(gp1, point);
            paint.setColor(Color.BLUE);
            Point point2 = new Point();
            projection.toPixels(gp2, point2);
            paint.setStrokeWidth(2);
            canvas.drawLine((float) point.x, (float) point.y, (float) point2.x,
                    (float) point2.y, paint);
        }
        return super.draw(canvas, mapView, shadow, when);
    }

    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow) {
        // TODO Auto-generated method stub

        super.draw(canvas, mapView, shadow);
    }

}

This is full source code to draw direction path from source latitude and longitude to destination latitude and longitude. I have changed the above code to fit for latitude and longitude rather than source and destination. So anyone who is accessing his latitude and longitude through his gps can get the direction from his gps device to the destination coordinates.

Thanks to above answers we could make such a change and get path direction.

public class DrawMapActivity extends MapActivity {
	 MapView myMapView = null;
	 MapController myMC = null;
	 GeoPoint geoPoint = null;
	 @Override
	 public void onCreate(Bundle savedInstanceState) {
	  super.onCreate(savedInstanceState);

	  setContentView(R.layout.main);
	  myMapView = (MapView) findViewById(R.id.mapview);

	  geoPoint = null;
	  myMapView.setSatellite(false);
	  double fromLat = 12.303534;
	  double fromLong = 76.64611;
      double toLat = 12.9715987;
      double toLong = 77.5945627;

	  String sourceLat = Double.toString(fromLat);
	  String sourceLong = Double.toString(fromLong);
	  String destinationLat = Double.toString(toLat);
	  String destinationLong = Double.toString(toLong);
	  
	  String pairs[] = getDirectionData(sourceLat,sourceLong, destinationLat, destinationLong );
	  String[] lngLat = pairs[0].split(",");

	  // STARTING POINT
	  GeoPoint startGP = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6), (int) (Double.parseDouble(lngLat[0]) * 1E6));
	  
	  myMC = myMapView.getController();
	  geoPoint = startGP;
	  myMC.setCenter(geoPoint);
	  myMC.setZoom(10);
	  myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));

	  // NAVIGATE THE PATH

	  GeoPoint gp1;
	  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));
	   myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));
	   Log.d("xxx", "pair:" + pairs[i]);
	  }

	  // END POINT
	  myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));

	  myMapView.getController().animateTo(startGP);
	  myMapView.setBuiltInZoomControls(true);
	  myMapView.displayZoomControls(true);

	 }

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

	 private String[] getDirectionData(String sourceLat, String sourceLong, String destinationLat, String destinationLong) {

	  
	  String urlString = "http://maps.google.com/maps?f=d&hl=en&" +"saddr="+sourceLat+","+sourceLong+"&daddr="+destinationLat+","+destinationLong + "&ie=UTF8&0&om=0&output=kml";
	  Log.d("URL", urlString);
	  Document doc = null;
	  HttpURLConnection urlConnection = null;
	  URL url = null;
	  String pathConent = "";

	  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());

	  } catch (Exception e) {
	  }

	  NodeList nl = doc.getElementsByTagName("LineString");
	  for (int s = 0; s < nl.getLength(); s++) {
	   Node rootNode = nl.item(s);
	   NodeList configItems = rootNode.getChildNodes();
	   for (int x = 0; x < configItems.getLength(); x++) {
	    Node lineStringNode = configItems.item(x);
	    NodeList path = lineStringNode.getChildNodes();
	    pathConent = path.item(0).getNodeValue();
	   }
	  }
	  String[] tempContent = pathConent.split(" ");
	  return tempContent;
	 }

	}


	//*****************************************************************************

	

	 class DirectionPathOverlay extends Overlay {

	    private GeoPoint gp1;
	    private GeoPoint gp2;

	    public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {
	        this.gp1 = gp1;
	        this.gp2 = gp2;
	    }

	    @Override
	    public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
	            long when) {
	        // TODO Auto-generated method stub
	        Projection projection = mapView.getProjection();
	        if (shadow == false) {

	            Paint paint = new Paint();
	            paint.setAntiAlias(true);
	            Point point = new Point();
	            projection.toPixels(gp1, point);
	            paint.setColor(Color.BLUE);
	            Point point2 = new Point();
	            projection.toPixels(gp2, point2);
	            paint.setStrokeWidth(2);
	            canvas.drawLine((float) point.x, (float) point.y, (float) point2.x,(float) point2.y, paint);
	        }
	        return super.draw(canvas, mapView, shadow, when);
	    }

	    @Override
	    public void draw(Canvas canvas, MapView mapView, boolean shadow) {
	        // TODO Auto-generated method stub

	        super.draw(canvas, mapView, shadow);
	    }

	}

Hope it helps for other Stack Overflow users

This can be done by using intents too:

  final Intent intent = new Intent(Intent.ACTION_VIEW,
    Uri.parse(
            "http://maps.google.com/maps?" +
            "saddr="+YOUR_START_LONGITUDE+","+YOUR_START_LATITUDE+"&daddr="YOUR_END_LONGITUDE+","+YOUR_END_LATITUDE));
         intent.setClassName(
          "com.google.android.apps.maps",
          "com.google.android.maps.MapsActivity");
   startActivity(intent);

It is really easy with Google Maps Android API v2

Just copy the example from Developer documentation

(of course you have to init your map first)

GoogleMap map;
 // ... get a map.
 // Add a thin red line from London to New York.
 Polyline line = map.addPolyline(new PolylineOptions()
     .add(new LatLng(51.5, -0.1), new LatLng(40.7, -74.0))
     .width(5)
     .color(Color.RED));

Yes you need to use overlays.

You need to get the MapView's overlays and add your new overlay onto it.

Your class extends Overlay, which is a transparent canvas in which you can draw on it like any other canvas.

You can use mapView.getProjection() to get projection of map view.

...

More info found here: http://blogoscoped.com/archive/2008-12-15-n14.html

You can get the projection from the MapView object which is passed into the draw() method: mapv.getProjection().toPixels(gP1, p1);

public class MainActivity extends FragmentActivity  {

 
  List<Overlay> mapOverlays;
  GeoPoint point1, point2;
  LocationManager locManager;
  Drawable drawable;
  Document document;
  GMapV2GetRouteDirection v2GetRouteDirection;
  LatLng fromPosition;
  LatLng toPosition;
  GoogleMap mGoogleMap;
  MarkerOptions markerOptions;
  Location location ;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        v2GetRouteDirection = new GMapV2GetRouteDirection();
      SupportMapFragment supportMapFragment = (SupportMapFragment) getSupportFragmentManager()
        .findFragmentById(R.id.map);
        mGoogleMap = supportMapFragment.getMap();

        // Enabling MyLocation in Google Map
        mGoogleMap.setMyLocationEnabled(true);
        mGoogleMap.getUiSettings().setZoomControlsEnabled(true);
        mGoogleMap.getUiSettings().setCompassEnabled(true);
        mGoogleMap.getUiSettings().setMyLocationButtonEnabled(true);
        mGoogleMap.getUiSettings().setAllGesturesEnabled(true);
        mGoogleMap.setTrafficEnabled(true);
        mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(12));
        markerOptions = new MarkerOptions();
        fromPosition = new LatLng(11.663837, 78.147297);
        toPosition = new LatLng(11.723512, 78.466287);
        GetRouteTask getRoute = new GetRouteTask();
        getRoute.execute();
  }
  /**
   *
   * @author VIJAYAKUMAR M
   * This class Get Route on the map
   *
   */
  private class GetRouteTask extends AsyncTask<String, Void, String> {
       
        private ProgressDialog Dialog;
        String response = "";
        @Override
        protected void onPreExecute() {
              Dialog = new ProgressDialog(MainActivity.this);
              Dialog.setMessage("Loading route...");
              Dialog.show();
        }

        @Override
        protected String doInBackground(String... urls) {
              //Get All Route values
                         document = v2GetRouteDirection.getDocument(fromPosition, toPosition,          GMapV2GetRouteDirection.MODE_DRIVING);
                    response = "Success";
              return response;

        }

        @Override
        protected void onPostExecute(String result) {
              mGoogleMap.clear();
              if(response.equalsIgnoreCase("Success")){
              ArrayList<LatLng> directionPoint = v2GetRouteDirection.getDirection(document);
              PolylineOptions rectLine = new PolylineOptions().width(10).color(
                          Color.RED);

              for (int i = 0; i < directionPoint.size(); i++) {
                    rectLine.add(directionPoint.get(i));
              }
              // Adding route on the map
              mGoogleMap.addPolyline(rectLine);
              markerOptions.position(toPosition);
              markerOptions.draggable(true);
              mGoogleMap.addMarker(markerOptions);

              }
             
              Dialog.dismiss();
        }
  }
  @Override
  protected void onStop() {
        super.onStop();
        finish();
    }
 }

Route Helper class

 public class GMapV2GetRouteDirection {
  public final static String MODE_DRIVING = "driving";
  public final static String MODE_WALKING = "walking";

  public GMapV2GetRouteDirection() { }

  public Document getDocument(LatLng start, LatLng end, String mode) {
    String url = "http://maps.googleapis.com/maps/api/directions/xml?"
            + "origin=" + start.latitude + "," + start.longitude 
            + "&destination=" + end.latitude + "," + end.longitude
            + "&sensor=false&units=metric&mode=driving";

    try {
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpPost httpPost = new HttpPost(url);
        HttpResponse response = httpClient.execute(httpPost, localContext);
        InputStream in = response.getEntity().getContent();
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = builder.parse(in);
        return doc;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
  }

  public String getDurationText (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("duration");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "text"));
    Log.i("DurationText", node2.getTextContent());
    return node2.getTextContent();
 }

 public int getDurationValue (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("duration");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "value"));
    Log.i("DurationValue", node2.getTextContent());
    return Integer.parseInt(node2.getTextContent());
  }

  public String getDistanceText (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("distance");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "text"));
    Log.i("DistanceText", node2.getTextContent());
    return node2.getTextContent();
  }

  public int getDistanceValue (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("distance");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "value"));
    Log.i("DistanceValue", node2.getTextContent());
    return Integer.parseInt(node2.getTextContent());
  }

  public String getStartAddress (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("start_address");
    Node node1 = nl1.item(0);
    Log.i("StartAddress", node1.getTextContent());
    return node1.getTextContent();
  }

  public String getEndAddress (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("end_address");
    Node node1 = nl1.item(0);
    Log.i("StartAddress", node1.getTextContent());
    return node1.getTextContent();
  }

  public String getCopyRights (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("copyrights");
    Node node1 = nl1.item(0);
    Log.i("CopyRights", node1.getTextContent());
    return node1.getTextContent();
  }

   public ArrayList<LatLng> getDirection (Document doc) {
    NodeList nl1, nl2, nl3;
    ArrayList<LatLng> listGeopoints = new ArrayList<LatLng>();
    nl1 = doc.getElementsByTagName("step");
    if (nl1.getLength() > 0) {
        for (int i = 0; i < nl1.getLength(); i++) {
            Node node1 = nl1.item(i);
            nl2 = node1.getChildNodes();

            Node locationNode = nl2.item(getNodeIndex(nl2, "start_location"));
            nl3 = locationNode.getChildNodes();
            Node latNode = nl3.item(getNodeIndex(nl3, "lat"));
            double lat = Double.parseDouble(latNode.getTextContent());
            Node lngNode = nl3.item(getNodeIndex(nl3, "lng"));
            double lng = Double.parseDouble(lngNode.getTextContent());
            listGeopoints.add(new LatLng(lat, lng));

            locationNode = nl2.item(getNodeIndex(nl2, "polyline"));
            nl3 = locationNode.getChildNodes();
            latNode = nl3.item(getNodeIndex(nl3, "points"));
            ArrayList<LatLng> arr = decodePoly(latNode.getTextContent());
            for(int j = 0 ; j < arr.size() ; j++) {
                listGeopoints.add(new LatLng(arr.get(j).latitude, arr.get(j).longitude));
            }

            locationNode = nl2.item(getNodeIndex(nl2, "end_location"));
            nl3 = locationNode.getChildNodes();
            latNode = nl3.item(getNodeIndex(nl3, "lat"));
            lat = Double.parseDouble(latNode.getTextContent());
            lngNode = nl3.item(getNodeIndex(nl3, "lng"));
            lng = Double.parseDouble(lngNode.getTextContent());
            listGeopoints.add(new LatLng(lat, lng));
        }
    }

    return listGeopoints;
 }

 private int getNodeIndex(NodeList nl, String nodename) {
    for(int i = 0 ; i < nl.getLength() ; i++) {
        if(nl.item(i).getNodeName().equals(nodename))
            return i;
    }
    return -1;
 }

 private ArrayList<LatLng> decodePoly(String encoded) {
    ArrayList<LatLng> poly = new ArrayList<LatLng>();
    int index = 0, len = encoded.length();
    int lat = 0, lng = 0;
    while (index < len) {
        int b, shift = 0, result = 0;
        do {
            b = encoded.charAt(index++) - 63;
            result |= (b & 0x1f) << shift;
            shift += 5;
        } while (b >= 0x20);
        int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
        lat += dlat;
        shift = 0;
        result = 0;
        do {
            b = encoded.charAt(index++) - 63;
            result |= (b & 0x1f) << shift;
            shift += 5;
        } while (b >= 0x20);
        int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
        lng += dlng;

        LatLng position = new LatLng((double) lat / 1E5, (double) lng / 1E5);
        poly.add(position);
    }
    return poly;
  }
 }

just i will find draw with some rectangle in mapview just we want change paint as we like

EmptyOverlay.java

public class EmptyOverlay extends Overlay {
private float x1,y1;
private MapExampleActivity mv = null;
private Overlay overlay = null;

public EmptyOverlay(MapExampleActivity mapV){
	mv = mapV;
}

@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
		long when) {
	// TODO Auto-generated method stub
	return super.draw(canvas, mapView, shadow, when);
}

@Override
public boolean onTouchEvent(MotionEvent e, MapView mapView) {
	if(mv.isEditMode()){
		if(e.getAction() == MotionEvent.ACTION_DOWN){
			//when user presses the map add a new overlay to the map
			//move events will be catched by newly created overlay
			x1 = y1 = 0;
			x1 = e.getX();
			y1 = e.getY();

			overlay = new MapOverlay(mv, x1, y1);
			mapView.getOverlays().add(overlay);
			
		}
		if(e.getAction() == MotionEvent.ACTION_MOVE){
		}
		//---when user lifts his finger---
        if (e.getAction() == MotionEvent.ACTION_UP) {                
        	
        }    
        return true;
	}
    return false;
}
}

MapExampleActivity.java

 public class MapExampleActivity extends MapActivity {
private MapView mapView;
private boolean isEditMode = false;
private Button toogle;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    
    toogle = (Button)findViewById(R.id.toogleMap);        
    toogle.setOnClickListener(new OnClickListener() {
		
		@Override
		public void onClick(View v) {
			toogleEditMode();
			
		}
	});
 
    mapView = (MapView)findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true); //display zoom controls
    //add one empty overlay acting as a overlay loader. This will catch press events and will add the actual overlays
    mapView.getOverlays().add(new EmptyOverlay(this));
    mapView.postInvalidate();
}
//toogle edit mode for drawing or navigating the map
private void toogleEditMode(){
	isEditMode = !isEditMode;
}

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

public boolean isEditMode(){
	return this.isEditMode;
}

public MapView getMapView(){
	return this.mapView;
}
}

MapOverlay.java

 public class MapOverlay extends Overlay {

private float x1,y1,x2,y2;
private GeoPoint p1=null,p2=null;
private MapExampleActivity mv = null;
private Paint paint = new Paint();
private boolean isUp = false;

//constructor receiving the initial point
public MapOverlay(MapExampleActivity mapV,float x,float y){
	paint.setStrokeWidth(2.0f);
	x1 = x;
	y1 = y;
	mv = mapV;
	p1 = mapV.getMapView().getProjection().fromPixels((int)x1,(int)y1);
}
//override draw method to add our custom drawings
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
		long when) {
	
	if(p1 != null && p2 != null){
		//get the 2 geopoints defining the area and transform them to pixels
		//this way if we move or zoom the map rectangle will follow accordingly
		Point screenPts1 = new Point();
        mapView.getProjection().toPixels(p1, screenPts1);
        Point screenPts2 = new Point();
        mapView.getProjection().toPixels(p2, screenPts2);
        
        //draw inner rectangle
        paint.setColor(0x4435EF56);
        paint.setStyle(Style.FILL);
        canvas.drawRect(screenPts1.x, screenPts1.y, screenPts2.x, screenPts2.y, paint);
		//draw outline rectangle
		paint.setColor(0x88158923);
		paint.setStyle(Style.STROKE);
		canvas.drawRect(screenPts1.x, screenPts1.y, screenPts2.x, screenPts2.y, paint);
	}
	return true;
}

@Override
public boolean onTouchEvent(MotionEvent e, MapView mapView) {
	if(mv.isEditMode() && !isUp){
		if(e.getAction() == MotionEvent.ACTION_DOWN){
			x1 = y1 = 0;
			x1 = e.getX();
			y1 = e.getY();
			p1 = mapView.getProjection().fromPixels((int)x1,(int)y1);
			
		}
		//here we constantly change geopoint p2 as we move out finger
		if(e.getAction() == MotionEvent.ACTION_MOVE){
			x2 = e.getX();
			y2 = e.getY();
			p2 = mapView.getProjection().fromPixels((int)x2,(int)y2);
			
		}
		//---when user lifts his finger---
        if (e.getAction() == MotionEvent.ACTION_UP) {                
            isUp = true;
        }    
        return true;
	}
    return false;
}
 }

see this http://n3vrax.wordpress.com/2011/08/13/drawing-overlays-on-android-map-view/

Try this one:
Add itemizedOverlay class:

public class AndroidGoogleMapsActivity extends MapActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // Displaying Zooming controls
        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        
      
        MapController mc = mapView.getController();
        double lat = Double.parseDouble("48.85827758964043");
        double lon = Double.parseDouble("2.294543981552124");
        GeoPoint geoPoint = new GeoPoint((int)(lat * 1E6), (int)(lon * 1E6));
        mc.animateTo(geoPoint);
        mc.setZoom(15);
        mapView.invalidate(); 
        
        
        /**
         * Placing Marker
         * */
        List<Overlay> mapOverlays = mapView.getOverlays();
        Drawable drawable = this.getResources().getDrawable(R.drawable.mark_red);
        AddItemizedOverlay itemizedOverlay = 
             new AddItemizedOverlay(drawable, this);
        
        
        OverlayItem overlayitem = new OverlayItem(geoPoint, "Hello", "Sample Overlay item");
        
        itemizedOverlay.addOverlay(overlayitem);
        mapOverlays.add(itemizedOverlay);
        
    }

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

Simply get route form this url and do next ...

> Origin ---> starting point latitude & longitude

> Destination---> ending point latitude & longitude

here i have put origin as Delhi latitude and longitude & destination as chandigarh latitude longitude

https://maps.googleapis.com/maps/api/directions/json?origin=28.704060,77.102493&destination=30.733315,76.779419&sensor=false&key="PUT YOUR MAP API KEY"

This worked for me. With the method mentioned here I was able to draw polylines on Google Maps V2. I drew a new line whenever the user location got changed, so the the polyline looks like the path followed by user on map.

Source code at. Github: prasang7/eTaxi-Meter

Please ignore other modules of this project related to distance calculation and User Interface if you are not interested in them.