Google direction route from current location to known location

Question

I use the MapsActivity class in this project. On my map you can see many markers. I have many known locations, but in my code I just display two locations for example.

I don't understand how to use the direction API and JSON. How can I display the route, distance, and travelling time from my current location (changing) to a known location (constant)?

public class MapsActivity extends FragmentActivity {

    private GoogleMap mMap; // Might be null if Google Play services APK is not available.
    private Map<Marker, Class<?>> allMarkersMap = new HashMap<Marker, Class<?>>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        setUpMapIfNeeded();
    }

    private void setUpMap() {
        Marker marker1 = mMap.addMarker(new MarkerOptions()
                .position(new LatLng(14.608177, 120.967422))
                .title("Sample2")
                .snippet("zzzzzzz"));
        allMarkersMap.put(marker1, MainActivity.class);

        Marker marker2 = mMap.addMarker(new MarkerOptions()
                .position(new LatLng(14.611335, 120.962160))
                .title("Sample1")
                .snippet("sssssss"));
        allMarkersMap.put(marker2, MainActivity2Activity.class);
        mMap.setMyLocationEnabled(true);

        mMap.setOnInfoWindowClickListener(new GoogleMap.OnInfoWindowClickListener() {
            @Override
            public void onInfoWindowClick(Marker marker) {
                Class<?> cls = allMarkersMap.get(marker);
                        Intent intent = new Intent(MapsActivity.this, cls);
                startActivity(intent);
            }
        });
    }

Answer 1

The code is for drawing the distance between any two points, start is the current location and the other is a location stored in the SQLite db.

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback ,GoogleApiClient.ConnectionCallbacks,
    GoogleApiClient.OnConnectionFailedListener,
    LocationListener {

private GoogleMap mMap;
ArrayList<LatLng> MarkerPoints;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
Marker mCurrLocationMarker;
LocationRequest mLocationRequest;
String lat, lon;
LatLng start;
LatLng dest;
String destlat;
String destlon;

public void setLat(String lat) {
    this.lat = lat;
}

public void setLon(String lon) {
    this.lon = lon;
}

public void setDestlat(String destlat) {
    this.destlat = destlat;
}

public void setDestlon(String destlon) {
    this.destlon = destlon;
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);

    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        checkLocationPermission();
    }
    // Initializing
    MarkerPoints = new ArrayList<>();

    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
}


/**
 * Manipulates the map once available.
 * This callback is triggered when the map is ready to be used.
 * This is where we can add markers or lines, add listeners or move the camera. In this case,
 * we just add a marker near Sydney, Australia.
 * If Google Play services is not installed on the device, the user will be prompted to install
 * it inside the SupportMapFragment. This method will only be triggered once the user has
 * installed Google Play services and returned to the app.
 */
@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;

    Log.d("OnmapREady fired", "fired");

    //Initialize Google Play Services
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            buildGoogleApiClient();
            mMap.setMyLocationEnabled(true);
        }
    }
    else {
        buildGoogleApiClient();
        mMap.setMyLocationEnabled(true);
    }


}

public void mapOperations(){

    Log.d("Map operations called","Hope");

    LatLng point = start;

    // Already two locations
    if (MarkerPoints.size() > 1) {
        MarkerPoints.clear();
        mMap.clear();
    }

    // Adding new item to the ArrayList
    MarkerPoints.add(start);

    // adding destination from database
    LocationsDB db = new LocationsDB(MapsActivity.this);
    String loc = db.getTermValues();
    Log.d("location from db",loc);
    String[] separated = loc.split(" ");



    //try {
    Double lt = Double.parseDouble(separated[0]);
    Double ln = Double.parseDouble(separated[1]);
    dest = new LatLng(lt,ln);



    MarkerPoints.add(dest);
    //}
    //catch(Exception e) {
    //   Log.d("Wrong target location", e.toString());
    //}


    // Creating MarkerOptions
    MarkerOptions options = new MarkerOptions();

    // Setting the position of the marker
    options.position(start);
    options.position(dest);

    /**
     * For the start location, the color of marker is GREEN and
     * for the end location, the color of marker is RED.
     */
    if (MarkerPoints.size() == 1) {
        options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
    } else if (MarkerPoints.size() == 2) {
        options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
    }


    // Add new marker to the Google Map Android API V2
    mMap.addMarker(options);

    // Checks, whether start and end locations are captured
    if (MarkerPoints.size() >= 2) {
        LatLng origin = MarkerPoints.get(0);
        LatLng dest = MarkerPoints.get(1);

        // Getting URL to the Google Directions API
        String url = getUrl(origin, dest);
        Log.d("onMapClick", url.toString());
        FetchUrl FetchUrl = new FetchUrl();

        // Start downloading json data from Google Directions API
        FetchUrl.execute(url);
        //move map camera
        mMap.moveCamera(CameraUpdateFactory.newLatLng(origin));
        mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
    }


}


private String getUrl(LatLng origin, LatLng dest) {

    // Origin of route
    String str_origin = "origin=" + origin.latitude + "," + origin.longitude;

    // Destination of route
    String str_dest = "destination=" + dest.latitude + "," + dest.longitude;


    // Sensor enabled
    String sensor = "sensor=false";

    // Building the parameters to the web service
    String parameters = str_origin + "&" + str_dest + "&" + sensor;

    // Output format
    String output = "json";

    // Building the url to the web service
    String url = "https://maps.googleapis.com/maps/api/directions/" + output + "?" + parameters;


    return url;
}

/**
 * A method to download json data from url
 */
private String downloadUrl(String strUrl) throws IOException {
    String data = "";
    InputStream iStream = null;
    HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(strUrl);

        // Creating an http connection to communicate with url
        urlConnection = (HttpURLConnection) url.openConnection();

        // Connecting to url
        urlConnection.connect();

        // Reading data from url
        iStream = urlConnection.getInputStream();

        BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

        StringBuffer sb = new StringBuffer();

        String line = "";
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }

        data = sb.toString();
        Log.d("downloadUrl", data.toString());
        br.close();

    } catch (Exception e) {
        Log.d("Exception", e.toString());
    } finally {
        iStream.close();
        urlConnection.disconnect();
    }
    return data;
}

// Fetches data from url passed
private class FetchUrl extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... url) {

        // For storing data from web service
        String data = "";

        try {
            // Fetching the data from web service
            data = downloadUrl(url[0]);
            Log.d("Background Task data", data.toString());
        } catch (Exception e) {
            Log.d("Background Task", e.toString());
        }
        return data;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);

        ParserTask parserTask = new ParserTask();

        // Invokes the thread for parsing the JSON data
        parserTask.execute(result);

    }
}

/**
 * A class to parse the Google Places in JSON format
 */
private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String, String>>>> {

    // Parsing the data in non-ui thread
    @Override
    protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {

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

        try {
            jObject = new JSONObject(jsonData[0]);
            Log.d("ParserTask",jsonData[0].toString());
            DataParser parser = new DataParser();
            Log.d("ParserTask", parser.toString());

            // Starts parsing data
            routes = parser.parse(jObject);
            Log.d("ParserTask","Executing routes");
            Log.d("ParserTask",routes.toString());

        } catch (Exception e) {
            Log.d("ParserTask",e.toString());
            e.printStackTrace();
        }
        return routes;
    }

    // Executes in UI thread, after the parsing process
    @Override
    protected void onPostExecute(List<List<HashMap<String, String>>> result) {
        ArrayList<LatLng> points;
        PolylineOptions lineOptions = null;

        // 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);

                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(10);
            lineOptions.color(Color.RED);

            Log.d("onPostExecute","onPostExecute lineoptions decoded");

        }

        // Drawing polyline in the Google Map for the i-th route
        if(lineOptions != null) {
            mMap.addPolyline(lineOptions);
        }
        else {
            Log.d("onPostExecute","without Polylines drawn");
        }
    }
}

protected synchronized void buildGoogleApiClient() {
    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
    mGoogleApiClient.connect();
}

@Override
public void onConnected(Bundle bundle) {

    Log.d("OnConnected fired","fired");

    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(1000);
    mLocationRequest.setFastestInterval(1000);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            == PackageManager.PERMISSION_GRANTED) {
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }

    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
            mGoogleApiClient);
    if (mLastLocation != null) {
        lat = String.valueOf(mLastLocation.getLatitude());
        lon = String.valueOf(mLastLocation.getLongitude());

        start = new LatLng(mLastLocation.getLatitude(),mLastLocation.getLongitude());


        Toast.makeText(this,"Connected",Toast.LENGTH_SHORT).show();

        mapOperations();
    }
    else{
        Toast.makeText(this,"Failed",Toast.LENGTH_LONG).show();
    }

}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onLocationChanged(Location location) {

    mLastLocation = location;
    if (mCurrLocationMarker != null) {
        mCurrLocationMarker.remove();
    }

    //Place current location marker
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
    MarkerOptions markerOptions = new MarkerOptions();
    markerOptions.position(latLng);
    markerOptions.title("Current Position");
    markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
    mCurrLocationMarker = mMap.addMarker(markerOptions);

    //move map camera
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    mMap.animateCamera(CameraUpdateFactory.zoomTo(11));

    //stop location updates
    if (mGoogleApiClient != null) {
        LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
    }

}

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {

}

public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
public boolean checkLocationPermission(){
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

        // Asking user if explanation is needed
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.ACCESS_FINE_LOCATION)) {

            // Show an explanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.

            //Prompt the user once explanation has been shown
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    MY_PERMISSIONS_REQUEST_LOCATION);


        } else {
            // No explanation needed, we can request the permission.
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    MY_PERMISSIONS_REQUEST_LOCATION);
        }
        return false;
    } else {
        return true;
    }
}

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_LOCATION: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted. Do the
                // contacts-related task you need to do.
                if (ContextCompat.checkSelfPermission(this,
                        Manifest.permission.ACCESS_FINE_LOCATION)
                        == PackageManager.PERMISSION_GRANTED) {

                    if (mGoogleApiClient == null) {
                        buildGoogleApiClient();
                    }
                    mMap.setMyLocationEnabled(true);
                }

            } else {

                // Permission denied, Disable the functionality that depends on this permission.
                Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
            }
            return;
        }

        // other 'case' lines to check for other permissions this app might request.
        // You can add here other case statements according to your requirement.
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
    }

}

This is the code for finding and drawing the routes between the points.

 public class DataParser {
/** Receives a JSONObject and returns a list of lists containing latitude and longitude */
public List<List<HashMap<String,String>>> parse(JSONObject jObject){

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

    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++){
                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
 * Courtesy : http://jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java
 * */
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;
}

}

Answer 2

Have a look at this tutorial:

Drawing driving route directions between two locations using Google Directions in Google Map Android API V2

It shows how to draw a route map between two points, calculate distance and travel time.

If you are having problems in following the tutorial, download the Android Studio sample project from the link below:

MapDemo.zip

public class DirectionsJSONParser {

    /** Receives a JSONObject and returns a list of lists containing latitude and longitude */
    public List<List<HashMap<String,String>>> parse(JSONObject jObject){

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

                        /** Traversing all points */
                        for(int l=0;l<list.size();l++){
                            HashMap<String, String> hm = new HashMap<String, String>();
                            hm.put("lat", Double.toString(((LatLng)list.get(l)).latitude) );
                            hm.put("lng", Double.toString(((LatLng)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
    * Courtesy : http://jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java
    * */
    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;
    }
}
MainActivity.Java

public class MainActivity extends FragmentActivity {

GoogleMap map;
ArrayList<LatLng> markerPoints;
TextView tvDistanceDuration;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    tvDistanceDuration = (TextView) findViewById(R.id.tv_distance_time);

    // Initializing
    markerPoints = new ArrayList<LatLng>();

    // Getting reference to SupportMapFragment of the activity_main
    SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

    // Getting Map for the SupportMapFragment
    map = fm.getMap();

    // Enable MyLocation Button in the Map
    map.setMyLocationEnabled(true);

    // Setting onclick event listener for the map
    map.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

        @Override
        public void onMapClick(LatLng point) {

            // Already two locations
            if (markerPoints.size() > 1) {
                markerPoints.clear();
                map.clear();
            }

            // Adding new item to the ArrayList
            markerPoints.add(point);

            // Creating MarkerOptions
            MarkerOptions options = new MarkerOptions();

            // Setting the position of the marker
            options.position(point);

            /**
             * For the start location, the color of marker is GREEN and
             * for the end location, the color of marker is RED.
             */
            if (markerPoints.size() == 1) {
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
            } else if (markerPoints.size() == 2) {
                options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
            }

            // Add new marker to the Google Map Android API V2
            map.addMarker(options);

            // Checks, whether start and end locations are captured
            if (markerPoints.size() >= 2) {
                LatLng origin = markerPoints.get(0);
                LatLng dest = markerPoints.get(1);

                // Getting URL to the Google Directions API
                String url = getDirectionsUrl(origin, dest);

                DownloadTask downloadTask = new DownloadTask();

                // Start downloading json data from Google Directions API
                downloadTask.execute(url);
            }
        }
    });
}

private String getDirectionsUrl(LatLng origin, LatLng dest) {

    // Origin of route
    String str_origin = "origin=" + origin.latitude + "," + origin.longitude;

    // Destination of route
    String str_dest = "destination=" + dest.latitude + "," + dest.longitude;

    // Sensor enabled
    String sensor = "sensor=false";

    // Building the parameters to the web service
    String parameters = str_origin + "&" + str_dest + "&" + sensor;

    // Output format
    String output = "json";

    // Building the url to the web service
    String url = "https://maps.googleapis.com/maps/api/directions/" + output + "?" + parameters;

    return url;
}

/**
 * A method to download json data from url
 */
private String downloadUrl(String strUrl) throws IOException {
    String data = "";
    InputStream iStream = null;
    HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(strUrl);

        // Creating an http connection to communicate with url
        urlConnection = (HttpURLConnection) url.openConnection();

        // Connecting to url
        urlConnection.connect();

        // Reading data from url
        iStream = urlConnection.getInputStream();

        BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

        StringBuffer sb = new StringBuffer();

        String line = "";
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }

        data = sb.toString();

        br.close();

    } catch (Exception e) {
        Log.d("Exception while downloading url", e.toString());
    } finally {
        iStream.close();
        urlConnection.disconnect();
    }
    return data;
}

// Fetches data from url passed
private class DownloadTask extends AsyncTask<String, Void, String> {

    // Downloading data in non-ui thread
    @Override
    protected String doInBackground(String... url) {

        // For storing data from web service
        String data = "";

        try {
            // Fetching the data from web service
            data = downloadUrl(url[0]);
        } catch (Exception e) {
            Log.d("Background Task", e.toString());
        }
        return data;
    }

    // Executes in UI thread, after the execution of
    // doInBackground()
    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);

        ParserTask parserTask = new ParserTask();

        // Invokes the thread for parsing the JSON data
        parserTask.execute(result);
    }
}

/**
 * A class to parse the Google Places in JSON format
 */
private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String, String>>>> {

    // Parsing the data in non-ui thread
    @Override
    protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {

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

        try {
            jObject = new JSONObject(jsonData[0]);
            DirectionsJSONParser parser = new DirectionsJSONParser();

            // Starts parsing data
            routes = parser.parse(jObject);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return routes;
    }

    // Executes in UI thread, after the parsing process
    @Override
    protected void onPostExecute(List<List<HashMap<String, String>>> result) {
        ArrayList<LatLng> points = null;
        PolylineOptions lineOptions = null;
        MarkerOptions markerOptions = new MarkerOptions();
        String distance = "";
        String duration = "";

        if (result.size() < 1) {
            Toast.makeText(getBaseContext(), "No Points", Toast.LENGTH_SHORT).show();
            return;
        }

        // Traversing through all the routes
        for (int i = 0; i < result.size(); i++) {
            points = new ArrayList<LatLng>();
            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(2);
            lineOptions.color(Color.RED);
        }

        tvDistanceDuration.setText("Distance:" + distance + ", Duration:" + duration);

        // Drawing polyline in the Google Map for the i-th route
        map.addPolyline(lineOptions);
    }
}