Draw path between two points using Google Maps Android API v2

Question

Google changed its map API for Android and introduced API V2. The previous codes for drawing path are not working with API V2.

I have managed to draw a path with API

Answer 1

Try below solution to draw path with animation and also get time and distance between two points.

DirectionHelper.java

public class DirectionHelper {

    public List<List<HashMap<String, String>>> parse(JSONObject jObject) {

        List<List<HashMap<String, String>>> routes = new ArrayList<>();
        JSONArray jRoutes;
        JSONArray jLegs;
        JSONArray jSteps;
        JSONObject jDistance = null;
        JSONObject jDuration = null;

        try {

            jRoutes = jObject.getJSONArray("routes");

            /** Traversing all routes */
            for (int i = 0; i < jRoutes.length(); i++) {
                jLegs = ((JSONObject) jRoutes.get(i)).getJSONArray("legs");
                List path = new ArrayList<>();

                /** Traversing all legs */
                for (int j = 0; j < jLegs.length(); j++) {

                    /** Getting distance from the json data */
                    jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
                    HashMap<String, String> hmDistance = new HashMap<String, String>();
                    hmDistance.put("distance", jDistance.getString("text"));

                    /** Getting duration from the json data */
                    jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
                    HashMap<String, String> hmDuration = new HashMap<String, String>();
                    hmDuration.put("duration", jDuration.getString("text"));

                    /** Adding distance object to the path */
                    path.add(hmDistance);

                    /** Adding duration object to the path */
                    path.add(hmDuration);

                    jSteps = ((JSONObject) jLegs.get(j)).getJSONArray("steps");

                    /** Traversing all steps */
                    for (int k = 0; k < jSteps.length(); k++) {
                        String polyline = "";
                        polyline = (String) ((JSONObject) ((JSONObject) jSteps.get(k)).get("polyline")).get("points");
                        List<LatLng> list = decodePoly(polyline);

                        /** Traversing all points */
                        for (int l = 0; l < list.size(); l++) {
                            HashMap<String, String> hm = new HashMap<>();
                            hm.put("lat", Double.toString((list.get(l)).latitude));
                            hm.put("lng", Double.toString((list.get(l)).longitude));
                            path.add(hm);
                        }
                    }
                    routes.add(path);
                }
            }

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


        return routes;
    }

    //Method to decode polyline points
    private List<LatLng> decodePoly(String encoded) {

        List<LatLng> poly = new ArrayList<>();
        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 p = new LatLng((((double) lat / 1E5)),
                    (((double) lng / 1E5)));
            poly.add(p);
        }

        return poly;
    }
}

GetPathFromLocation.java

public class GetPathFromLocation extends AsyncTask<String, Void, List<List<HashMap<String, String>>>> {

    private Context context;
    private String TAG = "GetPathFromLocation";
    private LatLng source, destination;
    private ArrayList<LatLng> wayPoint;
    private GoogleMap mMap;
    private boolean animatePath, repeatDrawingPath;
    private DirectionPointListener resultCallback;
    private ProgressDialog progressDialog;

    //https://www.mytrendin.com/draw-route-two-locations-google-maps-android/
    //https://www.androidtutorialpoint.com/intermediate/google-maps-draw-path-two-points-using-google-directions-google-map-android-api-v2/

    public GetPathFromLocation(Context context, LatLng source, LatLng destination, ArrayList<LatLng> wayPoint, GoogleMap mMap, boolean animatePath, boolean repeatDrawingPath, DirectionPointListener resultCallback) {
        this.context = context;
        this.source = source;
        this.destination = destination;
        this.wayPoint = wayPoint;
        this.mMap = mMap;
        this.animatePath = animatePath;
        this.repeatDrawingPath = repeatDrawingPath;
        this.resultCallback = resultCallback;
    }

    synchronized public String getUrl(LatLng source, LatLng dest, ArrayList<LatLng> wayPoint) {

        String url = "https://maps.googleapis.com/maps/api/directions/json?sensor=false&mode=driving&origin="
                + source.latitude + "," + source.longitude + "&destination=" + dest.latitude + "," + dest.longitude;
        for (int centerPoint = 0; centerPoint < wayPoint.size(); centerPoint++) {
            if (centerPoint == 0) {
                url = url + "&waypoints=optimize:true|" + wayPoint.get(centerPoint).latitude + "," + wayPoint.get(centerPoint).longitude;
            } else {
                url = url + "|" + wayPoint.get(centerPoint).latitude + "," + wayPoint.get(centerPoint).longitude;
            }
        }
        url = url + "&key=" + context.getResources().getString(R.string.google_api_key);

        return url;
    }

    public int getRandomColor() {
        Random rnd = new Random();
        return Color.argb(255, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog = new ProgressDialog(context);
        progressDialog.setMessage("Please wait...");
        progressDialog.setIndeterminate(false);
        progressDialog.setCancelable(false);
        progressDialog.show();
    }

    @Override
    protected List<List<HashMap<String, String>>> doInBackground(String... url) {

        String data;

        try {
            InputStream inputStream = null;
            HttpURLConnection connection = null;
            try {
                URL directionUrl = new URL(getUrl(source, destination, wayPoint));
                connection = (HttpURLConnection) directionUrl.openConnection();
                connection.connect();
                inputStream = connection.getInputStream();

                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                StringBuffer stringBuffer = new StringBuffer();

                String line = "";
                while ((line = bufferedReader.readLine()) != null) {
                    stringBuffer.append(line);
                }

                data = stringBuffer.toString();
                bufferedReader.close();

            } catch (Exception e) {
                Log.e(TAG, "Exception : " + e.toString());
                return null;
            } finally {
                inputStream.close();
                connection.disconnect();
            }
            Log.e(TAG, "Background Task data : " + data);

            //Second AsyncTask

            JSONObject jsonObject;
            List<List<HashMap<String, String>>> routes = null;

            try {
                jsonObject = new JSONObject(data);
                // Starts parsing data
                DirectionHelper helper = new DirectionHelper();
                routes = helper.parse(jsonObject);
                Log.e(TAG, "Executing Routes : "/*, routes.toString()*/);

                return routes;

            } catch (Exception e) {
                Log.e(TAG, "Exception in Executing Routes : " + e.toString());
                return null;
            }

        } catch (Exception e) {
            Log.e(TAG, "Background Task Exception : " + e.toString());
            return null;
        }
    }

    @Override
    protected void onPostExecute(List<List<HashMap<String, String>>> result) {
        super.onPostExecute(result);

        if (progressDialog.isShowing()) {
            progressDialog.dismiss();
        }

        ArrayList<LatLng> points;
        PolylineOptions lineOptions = null;
        String distance = "";
        String duration = "";

        // Traversing through all the routes
        for (int i = 0; i < result.size(); i++) {
            points = new ArrayList<>();
            lineOptions = new PolylineOptions();

            // Fetching i-th route
            List<HashMap<String, String>> path = result.get(i);

            // Fetching all the points in i-th route
            for (int j = 0; j < path.size(); j++) {
                HashMap<String, String> point = path.get(j);

                if (j == 0) {    // Get distance from the list
                    distance = (String) point.get("distance");
                    continue;
                } else if (j == 1) { // Get duration from the list
                    duration = (String) point.get("duration");
                    continue;
                }

                double lat = Double.parseDouble(point.get("lat"));
                double lng = Double.parseDouble(point.get("lng"));
                LatLng position = new LatLng(lat, lng);

                points.add(position);
            }

            // Adding all the points in the route to LineOptions
            lineOptions.addAll(points);
            lineOptions.width(8);
            lineOptions.color(Color.RED);
            //lineOptions.color(getRandomColor());

            if (animatePath) {
                final ArrayList<LatLng> finalPoints = points;
                ((AppCompatActivity) context).runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        PolylineOptions polylineOptions;
                        final Polyline greyPolyLine, blackPolyline;
                        final ValueAnimator polylineAnimator;

                        LatLngBounds.Builder builder = new LatLngBounds.Builder();
                        for (LatLng latLng : finalPoints) {
                            builder.include(latLng);
                        }
                        polylineOptions = new PolylineOptions();
                        polylineOptions.color(Color.RED);
                        polylineOptions.width(8);
                        polylineOptions.startCap(new SquareCap());
                        polylineOptions.endCap(new SquareCap());
                        polylineOptions.jointType(ROUND);
                        polylineOptions.addAll(finalPoints);
                        greyPolyLine = mMap.addPolyline(polylineOptions);

                        polylineOptions = new PolylineOptions();
                        polylineOptions.width(8);
                        polylineOptions.color(Color.WHITE);
                        polylineOptions.startCap(new SquareCap());
                        polylineOptions.endCap(new SquareCap());
                        polylineOptions.zIndex(5f);
                        polylineOptions.jointType(ROUND);

                        blackPolyline = mMap.addPolyline(polylineOptions);
                        polylineAnimator = ValueAnimator.ofInt(0, 100);
                        polylineAnimator.setDuration(5000);
                        polylineAnimator.setInterpolator(new LinearInterpolator());
                        polylineAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                            @Override
                            public void onAnimationUpdate(ValueAnimator valueAnimator) {
                                List<LatLng> points = greyPolyLine.getPoints();
                                int percentValue = (int) valueAnimator.getAnimatedValue();
                                int size = points.size();
                                int newPoints = (int) (size * (percentValue / 100.0f));
                                List<LatLng> p = points.subList(0, newPoints);
                                blackPolyline.setPoints(p);
                            }
                        });

                        polylineAnimator.addListener(new Animator.AnimatorListener() {
                            @Override
                            public void onAnimationStart(Animator animation) {

                            }

                            @Override
                            public void onAnimationEnd(Animator animation) {
                                if (repeatDrawingPath) {
                                    List<LatLng> greyLatLng = greyPolyLine.getPoints();
                                    if (greyLatLng != null) {
                                        greyLatLng.clear();

                                    }
                                    polylineAnimator.start();
                                }
                            }

                            @Override
                            public void onAnimationCancel(Animator animation) {
                                polylineAnimator.cancel();
                            }

                            @Override
                            public void onAnimationRepeat(Animator animation) {
                            }
                        });
                        polylineAnimator.start();
                    }
                });
            }

            Log.e(TAG, "PolylineOptions Decoded");
        }

        // Drawing polyline in the Google Map for the i-th route
        if (resultCallback != null && lineOptions != null)
            resultCallback.onPath(lineOptions, distance, duration);
    }
}

DirectionPointListener

public interface DirectionPointListener {
    public void onPath(PolylineOptions polyLine,String distance,String duration);
}

Now draw path using below code in your Activity

private GoogleMap mMap;
private ArrayList<LatLng> wayPoint = new ArrayList<>();
private SupportMapFragment mapFragment;

mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

@Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
            @Override
            public void onMapLoaded() {
                LatLngBounds.Builder builder = new LatLngBounds.Builder();

                /*Add Source Marker*/
                MarkerOptions markerOptions = new MarkerOptions();
                markerOptions.position(source);
                markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
                mMap.addMarker(markerOptions);
                builder.include(source);

                /*Add Destination Marker*/
                markerOptions = new MarkerOptions();
                markerOptions.position(destination);
                markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
                mMap.addMarker(markerOptions);
                builder.include(destination);

                LatLngBounds bounds = builder.build();

                int width = mapFragment.getView().getMeasuredWidth();
                int height = mapFragment.getView().getMeasuredHeight();
                int padding = (int) (width * 0.15); // offset from edges of the map 10% of screen

                CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding);

                mMap.animateCamera(cu);

                new GetPathFromLocation(context, source, destination, wayPoint, mMap, true, false, new DirectionPointListener() {
                    @Override
                    public void onPath(PolylineOptions polyLine, String distance, String duration) {
                        mMap.addPolyline(polyLine);
                        Log.e(TAG, "onPath :: Distance :: " + distance + " Duration :: " + duration);

                        binding.txtDistance.setText(String.format(" %s", distance));
                        binding.txtDuration.setText(String.format(" %s", duration));
                    }
                }).execute();
            }
        });
    }

OutPut

I hope this can help you!

Thank You.

Answer 2

in below code midpointsList is an ArrayList of waypoints

private String getMapsApiDirectionsUrl(GoogleMap googleMap, LatLng startLatLng, LatLng endLatLng, ArrayList<LatLng> midpointsList) {
    String origin = "origin=" + startLatLng.latitude + "," + startLatLng.longitude;

    String midpoints = "";
    for (int mid = 0; mid < midpointsList.size(); mid++) {
        midpoints += "|" + midpointsList.get(mid).latitude + "," + midpointsList.get(mid).longitude;
    }

    String waypoints = "waypoints=optimize:true" + midpoints + "|";

    String destination = "destination=" + endLatLng.latitude + "," + endLatLng.longitude;
    String key = "key=AIzaSyCV1sOa_7vASRBs6S3S6t1KofFvDhjohvI";

    String sensor = "sensor=false";
    String params = origin + "&" + waypoints + "&" + destination + "&" + sensor + "&" + key;
    String output = "json";
    String url = "https://maps.googleapis.com/maps/api/directions/" + output + "?" + params;


    Log.e("url", url);
    parseDirectionApidata(url, googleMap);
    return url;
}

Then copy and paste this url in your browser to check And the below code is to parse the url

    private void parseDirectionApidata(String url, final GoogleMap googleMap) {

    final JSONObject jsonObject = new JSONObject();

    try {

        AppUtill.getJsonWithHTTPPost(ViewMapActivity.this, 1, new ServiceCallBack() {
            @Override
            public void serviceCallBack(int id, JSONObject jsonResult) throws JSONException {

                if (jsonResult != null) {

                    Log.e("jsonRes", jsonResult.toString());

                    String status = jsonResult.optString("status");

                    if (status.equalsIgnoreCase("ok")) {
                        drawPath(jsonResult, googleMap);
                    }

                } else {

                    Toast.makeText(ViewMapActivity.this, "Unable to parse Directions Data", Toast.LENGTH_LONG).show();
                }

            }
        }, url, jsonObject);

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

    }
}

And then pass the result to the drawPath method

    public void drawPath(JSONObject jObject, GoogleMap googleMap) {

    List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String, String>>>();
    JSONArray jRoutes = null;
    JSONArray jLegs = null;
    JSONArray jSteps = null;
    List<LatLng> list = null;
    try {

        Toast.makeText(ViewMapActivity.this, "Drawing Path...", Toast.LENGTH_SHORT).show();
        jRoutes = jObject.getJSONArray("routes");

        /** Traversing all routes */
        for (int i = 0; i < jRoutes.length(); i++) {
            jLegs = ((JSONObject) jRoutes.get(i)).getJSONArray("legs");
            List path = new ArrayList<HashMap<String, String>>();

            /** Traversing all legs */
            for (int j = 0; j < jLegs.length(); j++) {
                jSteps = ((JSONObject) jLegs.get(j)).getJSONArray("steps");

                /** Traversing all steps */
                for (int k = 0; k < jSteps.length(); k++) {
                    String polyline = "";
                    polyline = (String) ((JSONObject) ((JSONObject) jSteps.get(k)).get("polyline")).get("points");
                    list = decodePoly(polyline);
                }
                Log.e("list", list.toString());
                routes.add(path);
                Log.e("routes", routes.toString());
                if (list != null) {
                    Polyline line = googleMap.addPolyline(new PolylineOptions()
                            .addAll(list)
                            .width(12)
                            .color(Color.parseColor("#FF0000"))//Google maps blue color #05b1fb
                            .geodesic(true)
                    );
                }
            }
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }

}

  private List<LatLng> decodePoly(String encoded) {

    List<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 p = new LatLng((((double) lat / 1E5)),
                (((double) lng / 1E5)));
        poly.add(p);
    }

    return poly;
}

decode poly function is to decode the points(lat and long) provided by Directions API in encoded form

Answer 3

First of all we will get source and destination points between which we have to draw route. Then we will pass these attribute to below function.

 public String makeURL (double sourcelat, double sourcelog, double destlat, double destlog ){
        StringBuilder urlString = new StringBuilder();
        urlString.append("http://maps.googleapis.com/maps/api/directions/json");
        urlString.append("?origin=");// from
        urlString.append(Double.toString(sourcelat));
        urlString.append(",");
        urlString.append(Double.toString( sourcelog));
        urlString.append("&destination=");// to
        urlString.append(Double.toString( destlat));
        urlString.append(",");
        urlString.append(Double.toString( destlog));
        urlString.append("&sensor=false&mode=driving&alternatives=true");
        urlString.append("&key=YOUR_API_KEY");
        return urlString.toString();
 }

This function will make the url that we will send to get Direction API response. Then we will parse that response . The parser class is

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";
    // constructor
    public JSONParser() {
    }
    public String getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();           

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }

            json = sb.toString();
            is.close();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }
        return json;

    }
}

This parser will return us string. We will call it like that.

JSONParser jParser = new JSONParser();
String json = jParser.getJSONFromUrl(url);

Now we will send this string to our drawpath function. The drawpath function is

public void drawPath(String  result) {

    try {
            //Tranform the string into a json object
           final JSONObject json = new JSONObject(result);
           JSONArray routeArray = json.getJSONArray("routes");
           JSONObject routes = routeArray.getJSONObject(0);
           JSONObject overviewPolylines = routes.getJSONObject("overview_polyline");
           String encodedString = overviewPolylines.getString("points");
           List<LatLng> list = decodePoly(encodedString);
           Polyline line = mMap.addPolyline(new PolylineOptions()
                                    .addAll(list)
                                    .width(12)
                                    .color(Color.parseColor("#05b1fb"))//Google maps blue color
                                    .geodesic(true)
                    );
           /*
           for(int z = 0; z<list.size()-1;z++){
                LatLng src= list.get(z);
                LatLng dest= list.get(z+1);
                Polyline line = mMap.addPolyline(new PolylineOptions()
                .add(new LatLng(src.latitude, src.longitude), new LatLng(dest.latitude,   dest.longitude))
                .width(2)
                .color(Color.BLUE).geodesic(true));
            }
           */
    } 
    catch (JSONException e) {

    }
} 

Above code will draw the path on mMap. The code of decodePoly is

private List<LatLng> decodePoly(String encoded) {

    List<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 p = new LatLng( (((double) lat / 1E5)),
                 (((double) lng / 1E5) ));
        poly.add(p);
    }

    return poly;
}

As direction call may take time so we will do all this in Asynchronous task. My Asynchronous task was

private class connectAsyncTask extends AsyncTask<Void, Void, String>{
    private ProgressDialog progressDialog;
    String url;
    connectAsyncTask(String urlPass){
        url = urlPass;
    }
    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        progressDialog = new ProgressDialog(MainActivity.this);
        progressDialog.setMessage("Fetching route, Please wait...");
        progressDialog.setIndeterminate(true);
        progressDialog.show();
    }
    @Override
    protected String doInBackground(Void... params) {
        JSONParser jParser = new JSONParser();
        String json = jParser.getJSONFromUrl(url);
        return json;
    }
    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);   
        progressDialog.hide();        
        if(result!=null){
            drawPath(result);
        }
    }
}

I hope it will help.

Answer 4

Dont know whether I should put this as answer or not...

I used @Zeeshan0026's solution to draw the path...and the problem was that if I draw path once, and then I do try to draw path once again, both two paths show and this continues...paths showing even when markers were deleted... while, ideally, old paths' shouldn't be there once new path is drawn / markers are deleted..

going through some other question over SO, I had the following solution

I add the following function in Zeeshan's class

 public void clearRoute(){

         for(Polyline line1 : polylines)
         {
             line1.remove();
         }

         polylines.clear();

     }

in my map activity, before drawing the path, I called this function.. example usage as per my app is

private Route rt;

rt.clearRoute();

            if (src == null) {
                Toast.makeText(getApplicationContext(), "Please select your Source", Toast.LENGTH_LONG).show();
            }else if (Destination == null) {
                Toast.makeText(getApplicationContext(), "Please select your Destination", Toast.LENGTH_LONG).show();
            }else if (src.equals(Destination)) {
                Toast.makeText(getApplicationContext(), "Source and Destinatin can not be the same..", Toast.LENGTH_LONG).show();
            }else{

                rt.drawRoute(mMap, MapsMainActivity.this, src,
                        Destination, false, "en");
            }

you can use rt.clearRoute(); as per your requirements.. Hoping that it will save a few minutes of someone else and will help some beginner in solving this issue..

Complete Class Code

see on github

Edit: here is part of code from mainactivity..

case R.id.mkrbtn_set_dest:
                    Destination = selmarker.getPosition();
                    destmarker = selmarker;
                    desShape = createRouteCircle(Destination, false);

                    if (src == null) {
                        Toast.makeText(getApplicationContext(),
                                "Please select your Source first...",
                                Toast.LENGTH_LONG).show();
                    } else if (src.equals(Destination)) {
                        Toast.makeText(getApplicationContext(),
                                "Source and Destinatin can not be the same..",
                                Toast.LENGTH_LONG).show();
                    } else {

                        if (isNetworkAvailable()) {
                            rt.drawRoute(mMap, MapsMainActivity.this, src,
                                    Destination, false, "en");
                            src = null;
                            Destination = null;

                        } else {
                            Toast.makeText(
                                    getApplicationContext(),
                                    "Internet Connection seems to be OFFLINE...!",
                                    Toast.LENGTH_LONG).show();

                        }

                    }

                    break;

Edit 2 as per comments

usage :

//variables as data members
GoogleMap mMap;
private Route rt;
static LatLng src;
static LatLng Destination;
//MapsMainActivity is my activity
//false for interim stops for traffic, google
// en language for html description returned

rt.drawRoute(mMap, MapsMainActivity.this, src,
                            Destination, false, "en");