How to draw path latitude and longitude values from database in map in android

Question

Hi am developing one application in that am displaying map with current location and longitude and latitude values and change that location. every 5 minutes am storing these latitude and longitude values in sqlitedatabase and am getting these database values its working fine. but, how to draw path using stored database values. please anybody tell me the solution.

code:

    PolylineOptions polylineOptions = new PolylineOptions();
    polylineOptions.color(Color.RED);
    polylineOptions.width(5);
    double latitude=Double.parseDouble(c.getString(0));
    double longitude=Double.parseDouble(c.getString(1));

    LatLng latlngval=new LatLng(latitude, longitude);
    Log.e("path", ""+latlngval);
    ArrayList<LatLng> latlnglist=new ArrayList<LatLng>();
    latlnglist.add(latlngval);

    for (int i = 0; i < latlnglist.size(); i++) {

        polylineOptions.add(latlnglist.get(i));

    }

what maps are you using? Google's, Here's, or OSM? – Wilik Sep 05 '15 at 14:19 — Wilik, Sep 05 '15 at 14:19
am using in this google maps – user3612165 Sep 07 '15 at 04:22 — user3612165, Sep 07 '15 at 04:22

Wilik · Accepted Answer · 2015-09-07T10:34:09.340

1

You can use Polyline

PolylineOptions polylineOptions = new PolylineOptions();
polylineOptions.color(Color.RED);
polylineOptions.width(5);
Cursor c = database.query( ... ); //select the latitude and longitude column
while (c.moveToNext()) {
    polylineOptions.add(new LatLng(Double.parseDouble(c.getString(0)), Double.parseDouble(c.getString(1))));
}
googleMap.addPolyline(polylineOptions);

edited Sep 07 '15 at 10:34

answered Sep 07 '15 at 05:47

Wilik

7,630
3
29
35

thank you for your response. am sending one code tell me is that is correct one or not. – user3612165 Sep 07 '15 at 06:42
am edit the code see once is this correct way or not. – user3612165 Sep 07 '15 at 06:47
I have updated my answer, you don't need to put it in an `ArrayList` first, hope this one helps. :) – Wilik Sep 07 '15 at 10:35
one more doubt how to find route from current location to destination location – user3612165 Sep 07 '15 at 11:56
to find route, you can use [Directions API](https://developers.google.com/maps/documentation/directions/intro) – Wilik Sep 07 '15 at 12:30
if u have any example code for draw route from current location to destination location pls send me.. – user3612165 Sep 09 '15 at 05:01
I haven't tried that, but you can check this answer http://stackoverflow.com/a/15053901/5292961, that library should be very useful :) – Wilik Sep 10 '15 at 06:19
Hi sir how to run google map in service that is in service class i want to write google map.onmylocationchange listener that is onmylocationchange method used in service. how can i use this. – user3612165 Sep 23 '15 at 05:09
I want to change location in background service how can i do this pls tell me. – user3612165 Sep 23 '15 at 05:11
please create a question for that – Wilik Sep 24 '15 at 05:40

score 0 · Answer 2 · answered Sep 07 '15 at 06:11

public 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(dist);
        userdata.setTime(time);
        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;
}

}

score 0 · Answer 3 · answered Sep 07 '15 at 07:17

0

may be this will help you..

http://javapapers.com/android/draw-lines-on-google-maps-android-api/

instead of taking hardcoded values(as in the example) retrieve the values from your database

answered Sep 07 '15 at 07:17

Maniya Joe

761
6
24

How to draw path latitude and longitude values from database in map in android

3 Answers3