fuzzy wuzzy fuzzy wuzzy - 3 months ago 15
Android Question

Android How to show route between markers on googlemaps

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 created. Now. I want to make markers on Point A and Point B to be hardcoded into the app and show the route on the map. It shall use the nearest road on the map. I've done some research but only find old code which dated 5 years back. Could anyone be kind enough to guide me through this.

The Point A and Point B is on LocationChanged method.

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;

import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v4.app.FragmentActivity;
import android.widget.Toast;

public class MainActivity extends FragmentActivity implements LocationListener {
private GoogleMap map;
private LocationManager locationManager;
private String provider;
LatLng coordinate;
Marker startPerc;

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


LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
boolean enabledGPS = service
.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean enabledWiFi = service
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

// Check if enabled and if not send user to the GSP settings
// Better solution would be to display a dialog and suggesting to
// go to the settings
if (!enabledGPS) {
Toast.makeText(this, "GPS signal not found", Toast.LENGTH_LONG).show();
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);

// Initialize the location fields
if (location != null) {
Toast.makeText(this, "Selected Provider " + provider,
Toast.LENGTH_SHORT).show();
onLocationChanged(location);
} else {

//do something
}


}

/* Request updates at startup */
@Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 300, 1, this);
}

/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {

double lat = location.getLatitude();
double lng = location.getLongitude();
Toast.makeText(this, "Location " + lat+","+lng,
Toast.LENGTH_LONG).show();
LatLng coordinate = new LatLng(lat, lng);
Toast.makeText(this, "Location " + coordinate.latitude+","+coordinate.longitude,
Toast.LENGTH_LONG).show();
if(map!=null){
map.clear();
}
//map.clear();
GoogleMap map;
if(startPerc!=null){
startPerc.remove();
}
map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
startPerc = map.addMarker(new MarkerOptions()
.position(coordinate)
.title("Start")
.snippet("Your Position")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
map.moveCamera(CameraUpdateFactory.newLatLngZoom(coordinate, 20));



map.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE))
.position(new LatLng(3.214732, 101.747047))
.title("Point A")
.snippet("Bus Stop")
.flat(true));

map.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE))
.position(new LatLng(3.214507, 101.749697))
.title("Point B")
.snippet("Bus Stop")
.flat(true));



startPerc.setIcon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher));

}


@ Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();

}


@Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();

}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub

}
void Delay(int Seconds){
long Time = 0;
Time = System.currentTimeMillis();
while(System.currentTimeMillis() < Time+(Seconds*1000));
}
}


New code provided by K Neeraj. It still crash sadly please check.

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;

import org.json.JSONObject;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;

import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;

import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.Settings;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.widget.Toast;

public class MainActivity extends FragmentActivity implements LocationListener {
private GoogleMap map;
private LocationManager locationManager;
private String provider;
LatLng coordinate;
Marker startPerc;

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



LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
boolean enabledGPS = service
.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean enabledWiFi = service
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

// Check if enabled and if not send user to the GSP settings
// Better solution would be to display a dialog and suggesting to
// go to the settings
if (!enabledGPS) {
Toast.makeText(this, "GPS signal not found", Toast.LENGTH_LONG).show();
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}

locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);



// Initialize the location fields
if (location != null) {
Toast.makeText(this, "Selected Provider " + provider,
Toast.LENGTH_SHORT).show();
onLocationChanged(location);
} else {

//do something
}


}


/* Request updates at startup */
@Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 300, 1, this);
}

/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {

double lat = location.getLatitude();
double lng = location.getLongitude();
Toast.makeText(this, "Location " + lat+","+lng,
Toast.LENGTH_LONG).show();
LatLng coordinate = new LatLng(lat, lng);
Toast.makeText(this, "Location " + coordinate.latitude+","+coordinate.longitude,
Toast.LENGTH_LONG).show();



if(map!=null){
map.clear();
}

GoogleMap map;
if(startPerc!=null){
startPerc.remove();
}
map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
startPerc = map.addMarker(new MarkerOptions()
.position(coordinate)
.title("Start")
.snippet("Your Position")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
map.moveCamera(CameraUpdateFactory.newLatLngZoom(coordinate, 12));




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);
}
}




@ Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();

}


@Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();

}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub

}
void Delay(int Seconds){
long Time = 0;
Time = System.currentTimeMillis();
while(System.currentTimeMillis() < Time+(Seconds*1000));
}
}


Then I created a new DirectionJSONParser.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.google.android.gms.maps.model.LatLng;

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;
}
}

Answer
@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.