[Android] 안드로이드 - Google map 폴리라인 그리기

Google 에서는 location 사이의 거리를 계산하고, 목적지 주소까지 어떻게 이동해야 할지 경로를 그려주는 API 를 제공한다. 이 경로를 그리는 기능에 다양한 교통수단 모드 ( 대중교통, 걷기, 자전거, 자동차 ) 를 지원한다.

아래의 문서에서 참고하여 공부하고 사용할 수 있다

https://developers.google.com/maps/documentation/directions/start

 

JSON Parser 클래스

package metaler.metaler.metaler_v2;

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

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

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

public class DirectionsJSONParser {


    /** Receives a JSONObject and returns a list of lists containing latitude and longitude
     * @return*/
    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 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 decodePoly(String encoded) {

        List 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;
    }
}

 

 

 

 

참고사이트 >>>

https://ahsensaeed.com/android-google-maps-direction-api-show-interactive-polylines/

https://medium.com/@trientran/android-working-with-google-maps-and-directions-api-44765433f19

https://www.journaldev.com/13373/android-google-map-drawing-route-two-points

https://www.wingsquare.com/blog/drawing-driving-route-directions-between-two-locations-using-google-directions-in-google-map-android/

https://breadboy.tistory.com/287