Develop Reference

Efficiently drawing large distances of Polylines on Google Maps

I am currently trying to draw routes between 2 destinations utilizing requested JSON data from Google's Directions API. The version I currently have works well with destinations within around 150 miles. Yet when I try drawing poly lines across a state the application crashes. Below is the snippet of my Async task.
public class FetchRouteStepsFromService extends AsyncTask<Void,Void,StringBuilder> {
private LocalBroadcastManager manager;
private String currentAddress;
private String destinationAddress;
public FetchRouteStepsFromService(String currentAddress, String destinationAddress, Context context){
this.currentAddress = currentAddress;
this.destinationAddress = destinationAddress;
manager = LocalBroadcastManager.getInstance(context);
}
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;
}
#Override
protected void onPostExecute(StringBuilder result) {
super.onPostExecute(result);
try{
JSONObject jsonObj = new JSONObject(result.toString());
JSONArray routesJSONArray = jsonObj.getJSONArray("routes");
JSONObject beforeLegsJSONObject = routesJSONArray.getJSONObject(0);
JSONArray legsJSONArray = beforeLegsJSONObject.getJSONArray("legs");
JSONObject beforeStepsJSONObject = legsJSONArray.getJSONObject(0);
JSONArray stepsJSONArray = beforeStepsJSONObject.getJSONArray("steps");
List<LatLng> test = new ArrayList<>();
ArrayList<PolylineOptions> options = new ArrayList<>();
map.clear();
for(int i = 0; i < stepsJSONArray.length(); i++){
JSONObject object = stepsJSONArray.getJSONObject(i);
JSONObject polyLineObject = object.getJSONObject("polyline");
String encodedPoly = polyLineObject.getString("points");//Holds the code for the polyline (String)
test = decodePoly(encodedPoly);
//Todo: Maybe create a separate asynctask to add latlngs on separate thread?
for(int j = 0; j < test.size();j++){
PolylineOptions options1;
if(j != test.size() -1) {
LatLng startLocation = test.get(j);
LatLng nextLocation = test.get(j + 1);
options1 = new PolylineOptions().add(startLocation, nextLocation).width(5).color(Color.GREEN).geodesic(true);
map.addPolyline(options1);
}else{
LatLng startLocation = test.get(j);
LatLng nextLocation = test.get(j);
options1 = new PolylineOptions().add(startLocation, nextLocation).width(5).color(Color.GREEN).geodesic(true);
map.addPolyline(options1);
}
}
}
dialog.dismiss();
updateUI();
}catch (Exception e){
e.printStackTrace();
}
}
#Override
protected StringBuilder doInBackground(Void... params) {
try{
StringBuilder jsonResults = new StringBuilder();
String googleMapUrl = "https://maps.googleapis.com/maps/api/directions/json?" +
"origin="+currentAddress+"&" +
"destination="+destinationAddress+"&key=MY_KEY";
URL url = new URL(googleMapUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(conn.getInputStream());
int read;
char[] buff = new char[3000];
while((read = in.read(buff,0,3000)) != -1 ){
jsonResults.append(buff,0,read);
}
return jsonResults;
}catch (Exception e){
Log.d("PlanTrip","doInBackgroud exception");
e.printStackTrace();
}
return null;
}
}
This is a local class within my Fragment which holds the Google Map. I previously have tried to make this AsyncTask its own class. This class would broadcast an intent consisting of PolyLineOptions which would be received by the fragment's BroadcastReceiver. Although this did not work either. Any resources, advice, or feedback would be greatly appreciated.
EDIT 1: Logcat during large request

Google Map v2: "Android" extracting waypoint from json after passing string array

The code below takes 2 address point and show it on the map, however i wanted to edit it by adding "waypoint" on the application. My question is, how can i extract the waypoint information from the json like how start and end information extracted below.
public class DirectionJsonParser {
private static final String DIRECTION_URL_API = "https://maps.googleapis.com/maps/api/directions/json?";
private static final String GOOGLE_API_KEY = "key";
private DirectionJsonListener listener;
private String origin;
private String destination;
public DirectionJsonParser(DirectionJsonListener listener, String origin, String destination) {
this.listener = listener;
this.origin = origin;
this.destination = destination;
}
public void execute() throws UnsupportedEncodingException {
listener.onDirectionFinderStart();
new DownloadRawData().execute(createUrl());
}
private String createUrl() throws UnsupportedEncodingException {
String urlOrigin = URLEncoder.encode(origin, "utf-8");
String urlDestination = URLEncoder.encode(destination, "utf-8");
return DIRECTION_URL_API + "origin=" + urlOrigin + "&destination=" + urlDestination + "&key=" + GOOGLE_API_KEY;
}
private class DownloadRawData extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
String link = params[0];
try {
URL url = new URL(link);
InputStream is = url.openConnection().getInputStream();
StringBuffer buffer = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String res) {
try {
parseJSon(res);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
private void parseJSon(String data) throws JSONException {
if (data == null)
return;
List<Route> routes = new ArrayList<Route>();
JSONObject jsonData = new JSONObject(data);
JSONArray jsonRoutes = jsonData.getJSONArray("routes");
for (int i = 0; i < jsonRoutes.length(); i++) {
JSONObject jsonRoute = jsonRoutes.getJSONObject(i);
Route route = new Route();
JSONObject overview_polylineJson = jsonRoute.getJSONObject("overview_polyline");
JSONArray jsonLegs = jsonRoute.getJSONArray("legs");
JSONObject jsonLeg = jsonLegs.getJSONObject(0);
JSONObject jsonDistance = jsonLeg.getJSONObject("distance");
JSONObject jsonDuration = jsonLeg.getJSONObject("duration");
JSONObject jsonEndLocation = jsonLeg.getJSONObject("end_location");
JSONObject jsonStartLocation = jsonLeg.getJSONObject("start_location");
route.distance = new Distance(jsonDistance.getString("text"), jsonDistance.getInt("value"));
route.duration = new Duration(jsonDuration.getString("text"), jsonDuration.getInt("value"));
route.endAddress = jsonLeg.getString("end_address");
route.startAddress = jsonLeg.getString("start_address");
route.startLocation = new LatLng(jsonStartLocation.getDouble("lat"), jsonStartLocation.getDouble("lng"));
route.endLocation = new LatLng(jsonEndLocation.getDouble("lat"), jsonEndLocation.getDouble("lng"));
route.points = decodePolyLine(overview_polylineJson.getString("points"));
routes.add(route);
}
listener.onDirectionFinderSuccess(routes);
}
private List<LatLng> decodePolyLine(final String poly) {
int len = poly.length();
int index = 0;
List<LatLng> decoded = new ArrayList<LatLng>();
int lat = 0;
int lng = 0;
while (index < len) {
int b;
int shift = 0;
int result = 0;
do {
b = poly.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 = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
decoded.add(new LatLng(
lat / 100000d, lng / 100000d
));
}
return decoded;
}
}

To convert JSON to String, you can use the JSONStringer. Implements toString() and toString(). Most application developers should use those methods directly and disregard this API.
JSONObject object = ...
String json = object.toString();
Each stringer may be used to encode a single top level value. Instances of this class are not thread safe. Although this class is nonfinal, it was not designed for inheritance and should not be subclassed. In particular, self-use by overrideable methods is not specified.
Stringers only encode well-formed JSON strings. In particular:
The stringer must have exactly one top-level array or object.
Lexical scopes must be balanced: every call to array() must have a matching call to 'endArray()' and every call to object() must have a matching call to endObject().
Arrays may not contain keys (property names).
Objects must alternate keys (property names) and values.
Values are inserted with either literal value calls, or by nesting arrays or objects.
Calls that would result in a malformed JSON string will fail with a JSONException. Some implementations of the API support at most 20 levels of nesting. Attempts to create more than 20 levels of nesting may fail with a JSONException.

Adding polylines in asynctask android

i'm having performance issues adding polylines and thought that maybe it'll be possible to add them in a separate class extending AsyncTask. However as i learned that UI elements can't be added in such way (and polylines are UI elements).
Why i'm having performance issues while drawing polylines? Well, my polylines are drawn not from pos A to pos B but from my current location to destination (which is hardcoded for the sake of application atm). So the polylines are drawn when onLocationChange listener is executed and thus my application requires lots of proccessing power.
Any ideas how to use AsyncTask on this occasion?
This is the main class:
mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
#Override
public void onMyLocationChange(Location arg0) {
// Get positions!
currentPOS = new LatLng(arg0.getLatitude(), arg0.getLongitude());
LatLng dst = new LatLng(58.378249, 26.714673);
CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(currentPOS, 13);
mMap.animateCamera(yourLocation);
mMap.addMarker(new MarkerOptions().position(dst).title("SCHOOL!"));
/*
// Remove comments to add marker to Liivi 2!
mMap.addMaker(new MarkerOptions().position(currentPOS).title("My POS"));
*/
if (currentPOS != null) {
//This is supposed to show directions
DirectionAPI directionAPI = new DirectionAPI(currentPOS, dst);
GoogleResponse googleResponse = null;
try {
googleResponse = (GoogleResponse) directionAPI.execute().get();
} catch (InterruptedException e) {
Log.e("CATCH","INTERRUPDED");
e.printStackTrace();
} catch (ExecutionException e) {
Log.e("CATCH","EXECUTIONEXCEPTION");
e.printStackTrace();
}
if (googleResponse.isOk()){
DrivingDirection drivingDirection = new DrivingDirection(googleResponse.getJsonObject());
polyline = drivingDirection.getTotalPolyline();
new drawPath(mMap,polyline).execute();
}
}
}
});
This is the Async for path drawing (which will result in an error due to UI conflict):
import android.graphics.Color;
import android.os.AsyncTask;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import java.util.ArrayList;
/**
* Created by Kevin on 7.10.2015.
*/
public class drawPath extends AsyncTask{
private static ArrayList<LatLng> polyline;
private static GoogleMap mMap;
public drawPath(GoogleMap map, ArrayList<LatLng> polyline){
this.mMap = map;
this.polyline = polyline;
}
#Override
protected Object doInBackground(Object[] params) {
for (int i = 0; i < polyline.size() - 1; i++) {
LatLng src = polyline.get(i);
LatLng dest = polyline.get(i + 1);
// mMap is the Map Object
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)
);
}
return null;
}
}

I solved this issue in a way that i did not add every polyline map separately but whole polyline. For example, before i had my location about 4km away from destination and it had 280 polylines between. On every onLocationChange these polylines were drawn one-by-one to map. Now they're all added at once - AsyncTask will create polylines in the background and in the post-execute they will be added.
#Override
protected Object doInBackground(Object[] params) {
PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true);
for (int z = 0; z < polyline.size(); z++) {
LatLng point = polyline.get(z);
options.add(point);
}
return options;
}
protected void onPostExecute(Object result) {
Polyline line = mMap.addPolyline((PolylineOptions) result);
}

you can use this code
ublic class DrawrootTask extends AsyncTask<String, String, String> {
private Context context;
public static boolean flagCompleted = false;
private GoogleMap googleMap;
private double source_lat = 0.0;
private double source_long = 0.0;
private double dest_lat = 0.0;
private double dest_long = 0.0;
Userdata userdata;
String tag = "DrawRootTask";
private ProgressDialog progressDialog;
public static double dist, time;
private Polyline line;
String distanceText = "";
String durationText = "";
public DrawrootTask(Context context, LatLng source, LatLng destination,
GoogleMap googleMap) {
source_lat = source.latitude;
source_long = source.longitude;
dest_lat = destination.latitude;
dest_long = destination.longitude;
this.googleMap = googleMap;
this.context = context;
userdata = Userdata.getinstance(context);
}
protected void onPreExecute() {
// // TODO Auto-generated method stub
super.onPreExecute();
progressDialog = new ProgressDialog(context);
progressDialog.setMessage(context.getResources().getString(
R.string.please_wait));
progressDialog.setIndeterminate(true);
progressDialog.show();
}
#Override
protected String doInBackground(String... params) {
String json = "";
// constructor
StringBuilder urlString = new StringBuilder();
urlString.append("http://maps.googleapis.com/maps/api/directions/json");
HashMap<String, String> keyValue = new HashMap<String, String>();
urlString.append("?origin=");// from
urlString.append(Double.toString(source_lat));
urlString.append(",");
urlString.append(Double.toString(source_long));
urlString.append("&destination=");// to
urlString.append(Double.toString(dest_lat));
urlString.append(",");
urlString.append(Double.toString(dest_long));
urlString.append("&sensor=false&mode=driving&alternatives=true");
// defaultHttpClient
String url = urlString.toString();
FetchUrl fetchurl = new FetchUrl();
json = fetchurl.fetchUrl(url, keyValue);
Log.e("Buffer Error", json);
return json;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
try {
progressDialog.dismiss();
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);
for (int z = 0; z < list.size() - 1; z++) {
LatLng src = list.get(z);
LatLng dest = list.get(z + 1);
line = googleMap.addPolyline(new PolylineOptions()
.add(new LatLng(src.latitude, src.longitude),
new LatLng(dest.latitude, dest.longitude))
// .width(8).color(Color.BLUE).geodesic(true));
.width(8)
.color(context.getResources().getColor(
R.color.actionbar_color)).geodesic(true));
Log.i("draw root", "" + "" + line.toString());
}
JSONArray legs = routes.getJSONArray("legs");
JSONObject steps = legs.getJSONObject(0);
JSONObject duration = steps.getJSONObject("duration");
JSONObject distance = steps.getJSONObject("distance");
distanceText = distance.getString("text");
durationText = duration.getString("text");
Log.i("draw root", "" + distance.toString());
dist = Double.parseDouble(distance.getString("text").replaceAll(
"[^\\.0123456789]", ""));
time = Double.parseDouble(duration.getString("text").replaceAll(
"[^\\.0123456789]", ""));
userdata.setDistance(distanceText);
userdata.setTime(durationText);
Log.d(tag, "distace is " + dist + " time is " + time);
flagCompleted = true;
} catch (JSONException e) {
Log.d("draw root", "" + e);
}
}
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;
}
}

Google Maps Directions - Which API?

I'm trying to get the directions from the user's current location to a user defined location in the app that I'm building. This seems like it should be a relatively easy thing to do but I'm getting stuck on which API to use.
Right now I've managed to hook up to the google directions API but the JSON it's returning is very strange (they've added a \n everywhere to make it human readable) which suggests to me that this API isn't the correct one for mobile.
I've also seen the google places API being recommended for this purpose but I can't seem to find out how to use it from the documentation.
Any help is greatly appreciated since I'm just a titch confused
EDIT: Just to clarify the questions is which API I should be using to get directions for maps?

I do not remember where I get it but this classes help me a lot, it includes if you want to draw the route.
GoogleParser.java
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.google.android.maps.GeoPoint;
import com.monumentos.log.Logger;
public class GoogleParser extends XMLParser implements Parser {
/** Distance covered. **/
private int distance;
public GoogleParser(String feedUrl) {
super(feedUrl);
}
/**
* Parses a url pointing to a Google JSON object to a Route object.
* #return a Route object based on the JSON object.
*/
public Route parse() {
// turn the stream into a string
final String result = convertStreamToString(this.getInputStream());
//Create an empty route
final Route route = new Route();
//Create an empty segment
final Segment segment = new Segment();
try {
//Tranform the string into a json object
final JSONObject json = new JSONObject(result);
//Get the route object
final JSONObject jsonRoute = json.getJSONArray("routes").getJSONObject(0);
//Get the leg, only one leg as we don't support waypoints
final JSONObject leg = jsonRoute.getJSONArray("legs").getJSONObject(0);
//Get the steps for this leg
final JSONArray steps = leg.getJSONArray("steps");
//Number of steps for use in for loop
final int numSteps = steps.length();
//Set the name of this route using the start & end addresses
route.setName(leg.getString("start_address") + " to " + leg.getString("end_address"));
//Get google's copyright notice (tos requirement)
route.setCopyright(jsonRoute.getString("copyrights"));
//Get the total length of the route.
route.setLength(leg.getJSONObject("distance").getInt("value"));
//Get any warnings provided (tos requirement)
if (!jsonRoute.getJSONArray("warnings").isNull(0)) {
route.setWarning(jsonRoute.getJSONArray("warnings").getString(0));
}
/* Loop through the steps, creating a segment for each one and
* decoding any polylines found as we go to add to the route object's
* map array. Using an explicit for loop because it is faster!
*/
for (int i = 0; i < numSteps; i++) {
//Get the individual step
final JSONObject step = steps.getJSONObject(i);
//Get the start position for this step and set it on the segment
final JSONObject start = step.getJSONObject("start_location");
final GeoPoint position = new GeoPoint((int) (start.getDouble("lat")*1E6),
(int) (start.getDouble("lng")*1E6));
segment.setPoint(position);
//Set the length of this segment in metres
final int length = step.getJSONObject("distance").getInt("value");
distance += length;
segment.setLength(length);
segment.setDistance(distance/1000);
//Strip html from google directions and set as turn instruction
segment.setInstruction(step.getString("html_instructions").replaceAll("<(.*?)*>", ""));
//Retrieve & decode this segment's polyline and add it to the route.
route.addPoints(decodePolyLine(step.getJSONObject("polyline").getString("points")));
//Push a copy of the segment to the route
route.addSegment(segment.copy());
}
} catch (JSONException e) {
Logger.appendLog( "Google JSON Parser - " + feedUrl);
}
return route;
}
/**
* Convert an inputstream to a string.
* #param input inputstream to convert.
* #return a String of the inputstream.
*/
private static String convertStreamToString(final InputStream input) {
final BufferedReader reader = new BufferedReader(new InputStreamReader(input));
final StringBuilder sBuf = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sBuf.append(line);
}
} catch (IOException e) {
Logger.appendLog( "Google parser, stream2string");
} finally {
try {
input.close();
} catch (IOException e) {
Logger.appendLog( "Google parser, stream2string");
}
}
return sBuf.toString();
}
/**
* Decode a polyline string into a list of GeoPoints.
* #param poly polyline encoded string to decode.
* #return the list of GeoPoints represented by this polystring.
*/
private List<GeoPoint> decodePolyLine(final String poly) {
int len = poly.length();
int index = 0;
List<GeoPoint> decoded = new ArrayList<GeoPoint>();
int lat = 0;
int lng = 0;
while (index < len) {
int b;
int shift = 0;
int result = 0;
do {
b = poly.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 = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
decoded.add(new GeoPoint(
(int) (lat*1E6 / 1E5), (int) (lng*1E6 / 1E5)));
}
return decoded;
}
}
Parser.java
public interface Parser {
public Route parse();
}
Route.java
import java.util.ArrayList;
import java.util.List;
import com.google.android.maps.GeoPoint;
public class Route {
private String name;
private final List<GeoPoint> points;
private List<Segment> segments;
private String copyright;
private String warning;
private String country;
private int length;
private String polyline;
public Route() {
points = new ArrayList<GeoPoint>();
segments = new ArrayList<Segment>();
}
public void addPoint(final GeoPoint p) {
points.add(p);
}
public void addPoints(final List<GeoPoint> points) {
this.points.addAll(points);
}
public List<GeoPoint> getPoints() {
return points;
}
public void addSegment(final Segment s) {
segments.add(s);
}
public List<Segment> getSegments() {
return segments;
}
/**
* #param name the name to set
*/
public void setName(final String name) {
this.name = name;
}
/**
* #return the name
*/
public String getName() {
return name;
}
/**
* #param copyright the copyright to set
*/
public void setCopyright(String copyright) {
this.copyright = copyright;
}
/**
* #return the copyright
*/
public String getCopyright() {
return copyright;
}
/**
* #param warning the warning to set
*/
public void setWarning(String warning) {
this.warning = warning;
}
/**
* #return the warning
*/
public String getWarning() {
return warning;
}
/**
* #param country the country to set
*/
public void setCountry(String country) {
this.country = country;
}
/**
* #return the country
*/
public String getCountry() {
return country;
}
/**
* #param length the length to set
*/
public void setLength(int length) {
this.length = length;
}
/**
* #return the length
*/
public int getLength() {
return length;
}
/**
* #param polyline the polyline to set
*/
public void setPolyline(String polyline) {
this.polyline = polyline;
}
/**
* #return the polyline
*/
public String getPolyline() {
return polyline;
}
}
RouteOverlay.java
public class RouteOverlay extends Overlay {
/** GeoPoints representing this routePoints. **/
private final List<GeoPoint> routePoints;
/** Colour to paint routePoints. **/
private int colour;
/** Alpha setting for route overlay. **/
private static final int ALPHA = 200;
/** Stroke width. **/
private static final float STROKE = 4.5f;
/** Route path. **/
private final Path path;
/** Point to draw with. **/
private final Point p;
/** Paint for path. **/
private final Paint paint;
/**
* Public constructor.
*
* #param route Route object representing the route.
* #param defaultColour default colour to draw route in.
*/
public RouteOverlay(final Route route, final int defaultColour) {
super();
routePoints = route.getPoints();
colour = defaultColour;
path = new Path();
p = new Point();
paint = new Paint();
}
#Override
public final void draw(final Canvas c, final MapView mv,
final boolean shadow) {
super.draw(c, mv, shadow);
paint.setColor(colour);
paint.setAlpha(ALPHA);
paint.setAntiAlias(true);
paint.setStrokeWidth(STROKE);
paint.setStyle(Paint.Style.STROKE);
redrawPath(mv);
c.drawPath(path, paint);
}
/**
* Set the colour to draw this route's overlay with.
*
* #param c Int representing colour.
*/
public final void setColour(final int c) {
colour = c;
}
/**
* Clear the route overlay.
*/
public final void clear() {
routePoints.clear();
}
/**
* Recalculate the path accounting for changes to
* the projection and routePoints.
* #param mv MapView the path is drawn to.
*/
private void redrawPath(final MapView mv) {
final Projection prj = mv.getProjection();
path.rewind();
final Iterator<GeoPoint> it = routePoints.iterator();
prj.toPixels(it.next(), p);
path.moveTo(p.x, p.y);
while (it.hasNext()) {
prj.toPixels(it.next(), p);
path.lineTo(p.x, p.y);
}
path.setLastPoint(p.x, p.y);
}
}
Segment.java
import com.google.android.maps.GeoPoint;
public class Segment {
/** Points in this segment. **/
private GeoPoint start;
/** Turn instruction to reach next segment. **/
private String instruction;
/** Length of segment. **/
private int length;
/** Distance covered. **/
private double distance;
/**
* Create an empty segment.
*/
public Segment() {
}
/**
* Set the turn instruction.
* #param turn Turn instruction string.
*/
public void setInstruction(final String turn) {
this.instruction = turn;
}
/**
* Get the turn instruction to reach next segment.
* #return a String of the turn instruction.
*/
public String getInstruction() {
return instruction;
}
/**
* Add a point to this segment.
* #param point GeoPoint to add.
*/
public void setPoint(final GeoPoint point) {
start = point;
}
/** Get the starting point of this
* segment.
* #return a GeoPoint
*/
public GeoPoint startPoint() {
return start;
}
/** Creates a segment which is a copy of this one.
* #return a Segment that is a copy of this one.
*/
public Segment copy() {
final Segment copy = new Segment();
copy.start = start;
copy.instruction = instruction;
copy.length = length;
copy.distance = distance;
return copy;
}
/**
* #param length the length to set
*/
public void setLength(final int length) {
this.length = length;
}
/**
* #return the length
*/
public int getLength() {
return length;
}
/**
* #param distance the distance to set
*/
public void setDistance(double distance) {
this.distance = distance;
}
/**
* #return the distance
*/
public double getDistance() {
return distance;
}
}
XMLParser.java
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import com.monumentos.log.Logger;
public class XMLParser {
// names of the XML tags
protected static final String MARKERS = "markers";
protected static final String MARKER = "marker";
protected URL feedUrl;
protected XMLParser(final String feedUrl) {
try {
this.feedUrl = new URL(feedUrl);
} catch (MalformedURLException e) {
Logger.appendLog( "XML parser - " + feedUrl);
}
}
protected InputStream getInputStream() {
try {
return feedUrl.openConnection().getInputStream();
} catch (IOException e) {
Logger.appendLog( "XML parser - " + feedUrl);
return null;
}
}
}
Hope it will helps you.
Calling api example:
Parser parser;
String jsonURL = "http://maps.googleapis.com/maps/api/directions/json?";
final StringBuffer sBuf = new StringBuffer(jsonURL);
sBuf.append("origin=");
sBuf.append( points.get(0).getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(points.get(0).getLongitudeE6()/1E6);
sBuf.append("&destination=");
sBuf.append(points.get(points.size()-1).getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(points.get(points.size()-1).getLongitudeE6()/1E6);
sBuf.append("&sensor=true&mode="+routeMode);
Logger.appendLog(sBuf.toString());
parser = new GoogleParser(sBuf.toString());
Route r = parser.parse();

You can parsing them using google http java client. Try this example

Google Maps Android V2 and Direction API

I'm developing an app where i need to know the path between the current user posistion and a point of interest.
I'm using android 2.3.3, google maps android v2 and direction api.
My problem is that all the code i have found is for the old version of the maps, and I also tried to adapt the code but i failed. I try to change GeoPoint (not supported in this new versione) in LatLng.
the problem is that i can't display the path, to do it i create a new polyline and i add it to the map.
i post my code:
Parser:
public interface Parser {
public Route parse();
}
XMLParser
public class XMLParser {
// names of the XML tags
protected static final String MARKERS = "markers";
protected static final String MARKER = "marker";
protected URL feedUrl;
protected XMLParser(final String feedUrl) {
try {
this.feedUrl = new URL(feedUrl);
} catch (MalformedURLException e) {
Log.e(e.getMessage(), "XML parser - " + feedUrl);
}
}
protected InputStream getInputStream() {
try {
return feedUrl.openConnection().getInputStream();
} catch (IOException e) {
Log.e(e.getMessage(), "XML parser - " + feedUrl);
return null;
}
}
}
JsonParser (parse the google direction json)
public class JsonParser extends XMLParser implements Parser {
/** Distance covered. **/
private int distance;
public JsonParser(String feedUrl) {
super(feedUrl);
}
/**
* Parses a url pointing to a Google JSON object to a Route object.
* #return a Route object based on the JSON object.
*/
public Route parse() {
// turn the stream into a string
final String result = convertStreamToString(this.getInputStream());
//Create an empty route
final Route route = new Route();
//Create an empty segment
final Segment segment = new Segment();
try {
//Tranform the string into a json object
final JSONObject json = new JSONObject(result);
//Get the route object
final JSONObject jsonRoute = json.getJSONArray("routes").getJSONObject(0);
//Get the leg, only one leg as we don't support waypoints
final JSONObject leg = jsonRoute.getJSONArray("legs").getJSONObject(0);
//Get the steps for this leg
final JSONArray steps = leg.getJSONArray("steps");
//Number of steps for use in for loop
final int numSteps = steps.length();
//Set the name of this route using the start & end addresses
route.setName(leg.getString("start_address") + " to " + leg.getString("end_address"));
//Get google's copyright notice (tos requirement)
route.setCopyright(jsonRoute.getString("copyrights"));
//Get the total length of the route.
route.setLength(leg.getJSONObject("distance").getInt("value"));
//Get any warnings provided (tos requirement)
if (!jsonRoute.getJSONArray("warnings").isNull(0)) {
route.setWarning(jsonRoute.getJSONArray("warnings").getString(0));
}
/* Loop through the steps, creating a segment for each one and
* decoding any polylines found as we go to add to the route object's
* map array. Using an explicit for loop because it is faster!
*/
for (int i = 0; i < numSteps; i++) {
//Get the individual step
final JSONObject step = steps.getJSONObject(i);
//Get the start position for this step and set it on the segment
final JSONObject start = step.getJSONObject("start_location");
final LatLng position = new LatLng(start.getDouble("lat"), start.getDouble("lng"));
segment.setPoint(position);
//Set the length of this segment in metres
final int length = step.getJSONObject("distance").getInt("value");
distance += length;
segment.setLength(length);
segment.setDistance(distance/1000);
//Strip html from google directions and set as turn instruction
segment.setInstruction(step.getString("html_instructions").replaceAll("<(.*?)*>", ""));
//Retrieve & decode this segment's polyline and add it to the route.
route.addPoints(decodePolyLine(step.getJSONObject("polyline").getString("points")));
//Push a copy of the segment to the route
route.addSegment(segment.copy());
}
} catch (JSONException e) {
Log.e(e.getMessage(), "Google JSON Parser - " + feedUrl);
}
return route;
}
/**
* Convert an inputstream to a string.
* #param input inputstream to convert.
* #return a String of the inputstream.
*/
private static String convertStreamToString(final InputStream input) {
final BufferedReader reader = new BufferedReader(new InputStreamReader(input));
final StringBuilder sBuf = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sBuf.append(line);
}
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
} finally {
try {
input.close();
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
}
}
return sBuf.toString();
}
/**
* Decode a polyline string into a list of LatLng.
* #param poly polyline encoded string to decode.
* #return the list of GeoPoints represented by this polystring.
*/
private List<LatLng> decodePolyLine(final String poly) {
int len = poly.length();
int index = 0;
List<LatLng> decoded = new LinkedList<LatLng>();
int lat = 0;
int lng = 0;
while (index < len) {
int b;
int shift = 0;
int result = 0;
do {
b = poly.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 = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
decoded.add(new LatLng((lat / 1E5),(lng / 1E5)));
}
return decoded;
}
}
Route (to save json info)
public class Route {
private String name;
private final List<LatLng> points;
private List<Segment> segments;
private String copyright;
private String warning;
private String country;
private int length;
private String polyline;
public Route() {
points = new LinkedList<LatLng>();
segments = new LinkedList<Segment>();
}
public void addPoint(final LatLng p) {
points.add(p);
}
public void addPoints(final List<LatLng> points) {
this.points.addAll(points);
}
public List<LatLng> getPoints() {
return points;
}
public void addSegment(final Segment s) {
segments.add(s);
}
public List<Segment> getSegments() {
return segments;
}
/**
* #param name the name to set
*/
public void setName(final String name) {
this.name = name;
}
/**
* #return the name
*/
public String getName() {
return name;
}
/**
* #param copyright the copyright to set
*/
public void setCopyright(String copyright) {
this.copyright = copyright;
}
/**
* #return the copyright
*/
public String getCopyright() {
return copyright;
}
/**
* #param warning the warning to set
*/
public void setWarning(String warning) {
this.warning = warning;
}
/**
* #return the warning
*/
public String getWarning() {
return warning;
}
/**
* #param country the country to set
*/
public void setCountry(String country) {
this.country = country;
}
/**
* #return the country
*/
public String getCountry() {
return country;
}
/**
* #param length the length to set
*/
public void setLength(int length) {
this.length = length;
}
/**
* #return the length
*/
public int getLength() {
return length;
}
/**
* #param polyline the polyline to set
*/
public void setPolyline(String polyline) {
this.polyline = polyline;
}
/**
* #return the polyline
*/
public String getPolyline() {
return polyline;
}
}
Segment:
public class Segment {
/** Points in this segment. **/
private LatLng start;
/** Turn instruction to reach next segment. **/
private String instruction;
/** Length of segment. **/
private int length;
/** Distance covered. **/
private double distance;
/**
* Create an empty segment.
*/
public Segment() {
}
/**
* Set the turn instruction.
* #param turn Turn instruction string.
*/
public void setInstruction(final String turn) {
this.instruction = turn;
}
/**
* Get the turn instruction to reach next segment.
* #return a String of the turn instruction.
*/
public String getInstruction() {
return instruction;
}
/**
* Add a point to this segment.
* #param point LatLng to add.
*/
public void setPoint(LatLng point) {
start = point;
}
/** Get the starting point of this
* segment.
* #return a LatLng
*/
public LatLng startPoint() {
return start;
}
/** Creates a segment which is a copy of this one.
* #return a Segment that is a copy of this one.
*/
public Segment copy() {
final Segment copy = new Segment();
copy.start = start;
copy.instruction = instruction;
copy.length = length;
copy.distance = distance;
return copy;
}
/**
* #param length the length to set
*/
public void setLength(final int length) {
this.length = length;
}
/**
* #return the length
*/
public int getLength() {
return length;
}
/**
* #param distance the distance to set
*/
public void setDistance(double distance) {
this.distance = distance;
}
/**
* #return the distance
*/
public double getDistance() {
return distance;
}
}
My MainActivity (there are 326 code line because of user localization, you can find it on google developer site, so we can just suppose to have two static point A and B and I want to go from A to B):
public class MainActivity extends FragmentActivity{
private GoogleMap map;
private Marker currentLocation;
private PolylineOptions pathLine;
private LatLng imhere = new LatLng(41.8549038,12.4618208);
private LatLng poi = new LatLng(41.89000,12.49324);
private LocationManager mLocationManager;
private Handler mHandler;
private boolean mUseBoth;
private Context context;
// Keys for maintaining UI states after rotation.
private static final String KEY_BOTH = "use_both";
// UI handler codes.
private static final int UPDATE_LATLNG = 2;
private static final int FIVE_SECONDS = 5000;
private static final int THREE_METERS = 3;
private static final int TWO_MINUTES = 1000 * 60 * 2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
Marker colosseoMarker = map.addMarker(new MarkerOptions()
.position(colosseo)
.title("Start")
.snippet("poi")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
Marker current pos = map.addMarker(new MarkerOptions()
.position(imhere)
.title("i'm here")
.snippet("here!")
.icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_launcher)));
context =this ;
map.setOnMarkerClickListener(new OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker marker) {
final String[] options = {"Calcola il Percorso"};
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Ottieni Informazioni aggiuntive");
builder.setPositiveButton("Calcola Percorso",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
LatLng start = new LatLng(imhere.latitude,imhere.longitude);
LatLng dest = new LatLng(poi.latitude, poi.longitude);
Route route = drawPath(start, dest);
List<LatLng> list= route.getPoints();
if(pathLine!= null) pathline =null;
pathLine = new PolylineOptions();
pathLine.addAll(list);
pathLine.color(Color.rgb(0,191,255));
map.addPolyline(pathLine);
}
});
AlertDialog alert = builder.create();
alert.show();
Toast.makeText(MainActivity.this, marker.getSnippet(),Toast.LENGTH_SHORT).show();
return true;
}
});
map.animateCamera(CameraUpdateFactory.newLatLngZoom(imhere, 12));
}
}
};
// Get a reference to the LocationManager object.
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
private Route drawPath(LatLng start, LatLng dest) {
Parser parser;
String jsonURL = "http://maps.google.com/maps/api/directions/json?";
final StringBuffer sBuf = new StringBuffer(jsonURL);
sBuf.append("origin=");
sBuf.append(start.latitude);
sBuf.append(',');
sBuf.append(start.longitude);
sBuf.append("&destination=");
sBuf.append(dest.latitude);
sBuf.append(',');
sBuf.append(dest.longitude);
sBuf.append("&sensor=true&mode=walking");
parser = new JsonParser(sBuf.toString());
Route r = parser.parse();
return r;
}
}
every suggestion is well accepted

If you don't need custom code try this lib https://github.com/jd-alexander/Google-Directions-Android only a few lines of code to do what you need.

I am doing like the following. I think this will help you.
Marker interestedMarker;
private void plot_direction(){
if (currentSelectedPin !=null) {
LatLng origin = new LatLng(currentLocation.getLatitude(),currentLocation.getLongitude());
new GoogleMapDirection(getActivity(), origin, interestedMarker.getPosition(), new DirectionListener() {
#Override
public void onDirectionPointsReceived(ArrayList<RouteModel> routeList, String distance, String duration) {
PolylineOptions lineOptions = null;
for (RouteModel route : routeList) {
lineOptions = new PolylineOptions();
lineOptions.addAll(route.getSteps());
lineOptions.width(20);
lineOptions.color(ContextCompat.getColor(getContext(), R.color.map_route));
}
//For removing existing line
if (routeMap!=null){
routeMap.remove();
}
if(lineOptions != null) {
routeMap = mMap.addPolyline(lineOptions);
}
}
});
}
}
GoogleMapDirection class is as follows
public class GoogleMapDirection {
private DirectionListener listener;
public GoogleMapDirection(final Activity activity, LatLng source, LatLng destination, DirectionListener listener){
this.listener=listener;
String url = null;
try {
url = "https://maps.googleapis.com/maps/api/directions/json?origin="+ URLEncoder.encode(Double.toString(source.latitude) + "," + Double.toString(source.longitude), "UTF-8") + "&destination=" + URLEncoder.encode(Double.toString(destination.latitude) + "," + Double.toString(destination.longitude), "UTF-8") + "&mode=driving&sensor=false&key=" + Config.GOOGLE_API_BROWSER_KEY;
Print.d(url);
} catch (UnsupportedEncodingException e) {
Print.exception(e);
}
JSONObject parameters = new JSONObject();
VolleyJsonBodyRequest.execute(activity, url, parameters, new VolleyResponseListener() {
#Override
public void onResponse(JSONObject response) {
try {
if (response.getString("status").equals("OK")) {
String distance = "NA";
String duration = "NA";
if (response.has("routes")){
JSONArray routesJArray = response.getJSONArray("routes");
if (routesJArray.length()>0){
if (routesJArray.getJSONObject(0).has("legs")){
JSONArray legsJArray = routesJArray.getJSONObject(0).getJSONArray("legs");
if (legsJArray.length()>0){
JSONObject firstLegsJObj = legsJArray.getJSONObject(0);
if (firstLegsJObj.has("distance")){
distance = firstLegsJObj.getJSONObject("distance").getString("text");
}
if (firstLegsJObj.has("duration")){
duration = firstLegsJObj.getJSONObject("duration").getString("text");
}
}
}
}
}
GoogleResponseParserTask task = new GoogleResponseParserTask(distance,duration);
task.execute(response);
}
} catch (JSONException e) {
Print.exception(e);
DialogWindow.showOK(activity, Config.MESSAGE_INVALID_RESPONSE_FORMAT, new DialogListenerOK() {
#Override
public void onOK() {
}
});
}
}
#Override
public void onErrorResponse(VolleyResponseError error) {
Print.e(error.getDetails());
DialogWindow.showOK(activity, error.getMessage(), new DialogListenerOK() {
#Override
public void onOK() {
}
});
}
});
}
/**
* A class to parse the Google Places in JSON format
*/
private class GoogleResponseParserTask extends AsyncTask<JSONObject, Integer, ArrayList<RouteModel>> {
String distance;
String duration;
private GoogleResponseParserTask(String distance, String duration){
this.distance=distance;
this.duration=duration;
}
#Override
protected ArrayList<RouteModel> doInBackground(JSONObject... jsonResponse) {
ArrayList<RouteModel> routes = null;
try {
routes = parse(jsonResponse[0]);
} catch (Exception e) {
Print.exception(e);
}
return routes;
}
#Override
protected void onPostExecute(ArrayList<RouteModel> result) {
listener.onDirectionPointsReceived(result,distance,duration);
}
}
/** Receives a JSONObject and returns a list of lists containing latitude and longitude */
public ArrayList<RouteModel> parse(JSONObject jObject){
ArrayList<RouteModel> routeList = 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");
ArrayList<LatLng> pointList = new ArrayList<>();
/** Traversing all legs */
for(int j=0;j<jLegs.length();j++){
jSteps = ((JSONObject)jLegs.get(j)).getJSONArray("steps");
JSONObject jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
JSONObject jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
String distance = jDistance.getString("text");
String duration = jDuration.getString("text");
/** Traversing all steps */
for(int k=0;k<jSteps.length();k++){
String polyline = (String)((JSONObject)((JSONObject)jSteps.get(k)).get("polyline")).get("points");
ArrayList<LatLng> stepList = decodePoly(polyline);
/** Traversing all points */
for(int l=0;l<stepList.size();l++){
LatLng point = new LatLng((stepList.get(l)).latitude, (stepList.get(l)).longitude);
pointList.add(point);
}
}
RouteModel routeModel = new RouteModel();
routeModel.setSteps(pointList);
routeModel.setDistance(distance);
routeModel.setDuration(duration);
routeList.add(routeModel);
}
}
} catch (JSONException e) {
e.printStackTrace();
}catch (Exception e){
}
return routeList;
}
/**
* Method to decode polyline points
* Courtesy : http://jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java
* */
private ArrayList<LatLng> decodePoly(String encoded) {
ArrayList<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;
}