com.webnetmobile.tools.GoogleMapRouteHelper.java Source code

Introduction

Here is the source code for com.webnetmobile.tools.GoogleMapRouteHelper.java

Source

package com.webnetmobile.tools;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONObject;

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

/*
 ******************************************************************************
 *
 * Copyright 2013 Webnet Marcin Orowski
 *
 * Licensed under the GPL License, Version 3.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.gnu.org/licenses/gpl-3.0.html
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 ******************************************************************************
 *
 * @author Marcin Orlowski <marcin.orlowski@webnet.pl>
 *
 ******************************************************************************
 */
public class GoogleMapRouteHelper {
    protected LatLng mPickup, mDropoff;
    protected List<LatLng> mRoutePoints = null;

    public GoogleMapRouteHelper(LatLng pickup, LatLng dropoff) {
        mPickup = pickup;
        mDropoff = dropoff;
    }

    public List<LatLng> getDirections() {
        if ((mPickup != null) || (mDropoff != null)) {

            HttpClient httpclient = new DefaultHttpClient();

            StringBuilder urlBuilder = new StringBuilder();

            urlBuilder.append("http://maps.googleapis.com/maps/api/directions/json");

            urlBuilder.append("?origin=");
            urlBuilder.append(Double.toString((double) mPickup.latitude));
            urlBuilder.append(",");
            urlBuilder.append(Double.toString((double) mPickup.longitude));

            urlBuilder.append("&destination=");
            urlBuilder.append(Double.toString((double) mDropoff.latitude));
            urlBuilder.append(",");
            urlBuilder.append(Double.toString((double) mDropoff.longitude));
            urlBuilder.append("&sensor=false&units=metric&mode=driving");

            HttpPost httppost = new HttpPost(urlBuilder.toString());
            HttpResponse response;
            try {
                response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity();
                InputStream is = null;

                is = entity.getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
                StringBuilder sb = new StringBuilder();
                sb.append(reader.readLine() + "\n");
                String line = "0";
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                is.close();
                reader.close();

                String result = sb.toString();

                JSONObject jsonObject = new JSONObject(result);

                JSONArray routeArray = jsonObject.getJSONArray("routes");
                if ((routeArray != null) && (routeArray.length() > 0)) {
                    JSONObject routes = routeArray.getJSONObject(0);
                    JSONObject overviewPolylines = routes.getJSONObject("overview_polyline");
                    String encodedString = overviewPolylines.getString("points");
                    mRoutePoints = decodePoly(encodedString);
                } else {
                    mRoutePoints = null;
                }

            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }

            return mRoutePoints;
        } else {
            throw new NullPointerException("Pickup or Dropoff cannot be null.");
        }
    }

    private List<LatLng> decodePoly(String poly) {

        List<LatLng> points = new LinkedList<LatLng>();

        int len = poly.length();
        int index = 0;
        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;

            points.add(new LatLng((lat / 1E5), (lng / 1E5)));
        }

        return points;
    }

}