Android How to show route between markers on googlemaps

Question

I\'m creating an App that will show the location of the user and put a marker to that position. After the user moves. The marker would be removed and a new marker would be c

Answer 1

Here is the full code with minor tweaks. It's just a prettier.

import android.app.Activity;
import android.os.AsyncTask;
import android.util.Log;

import com.eddress.R;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.PolylineOptions;

import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class GoogleMapsPath {

    public GoogleMap map;

    public GoogleMapsPath(Activity context, GoogleMap map, LatLng origin, LatLng dest){
        this.map = map;

        String url = getDirectionsUrl(origin,dest);
        FetchUrl FetchUrl = new FetchUrl();
        FetchUrl.execute(url);

    }

    // 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);

        }
    }


    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;
    }


    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;
    }


    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());
                DirectionsJSONParser parser = new DirectionsJSONParser();
                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(8);
                lineOptions.color(R.color.globalRedLight);

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

            }

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

Answer 2

@Override
public void onLocationChanged(Location location) {
....
 startPerc.setIcon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher));

// Assign your origin and destination
// These points are your markers coordinates
LatLng origin = new LatLng(3.214732, 101.747047);
LatLng dest = new LatLng(3.214507, 101.749697);

// 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();

        // 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);

                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);
        }

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

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 Route map between two points.