在 Android 中与 Google Direction API 保持距离

Question

http://maps.googleapis.com/maps/api/directions/json?origin=-20.291825,57.448668&destination=-20.179724,57.613463&sensor=false&mode=%22DRIVING%22

例如此链接生成以下内容：

"routes" : [
      {
         "bounds" : {
            "northeast" : {
               "lat" : -20.1765204,
               "lng" : 57.6137001
            },
           "southwest" : {
               "lat" : -20.2921672,
               "lng" : 57.4472155
            }
         },
         "copyrights" : "Map data ©2014 Google",
         "legs" : [
            {
               "distance" : {
                  "text" : "24.6 km",
                  "value" : 24628
               },

我只想提取距离并在android中显示

Answer 1

要从 Google 地图获取距离，您可以使用 Google Directions API 和 JSON 解析器来检索距离值。

样本方法

private double getDistanceInfo(double lat1, double lng1, String destinationAddress) {
            StringBuilder stringBuilder = new StringBuilder();
            Double dist = 0.0;
            try {

            destinationAddress = destinationAddress.replaceAll(" ","%20");    
            String url = "http://maps.googleapis.com/maps/api/directions/json?origin=" + latFrom + "," + lngFrom + "&destination=" + latTo + "," + lngTo + "&mode=driving&sensor=false";

            HttpPost httppost = new HttpPost(url);

            HttpClient client = new DefaultHttpClient();
            HttpResponse response;
            stringBuilder = new StringBuilder();


                response = client.execute(httppost);
                HttpEntity entity = response.getEntity();
                InputStream stream = entity.getContent();
                int b;
                while ((b = stream.read()) != -1) {
                    stringBuilder.append((char) b);
                }
            } catch (ClientProtocolException e) {
            } catch (IOException e) {
            }

            JSONObject jsonObject = new JSONObject();
            try {

                jsonObject = new JSONObject(stringBuilder.toString());

                JSONArray array = jsonObject.getJSONArray("routes");

                JSONObject routes = array.getJSONObject(0);

                JSONArray legs = routes.getJSONArray("legs");

                JSONObject steps = legs.getJSONObject(0);

                JSONObject distance = steps.getJSONObject("distance");

                Log.i("Distance", distance.toString());
                dist = Double.parseDouble(distance.getString("text").replaceAll("[^\\.0123456789]","") );

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            return dist;
        }

有关参数的详细信息以及可用的不同选项的更多详细信息，请参阅此。

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

Answer 2

public class ApiDirectionsAsyncTask extends AsyncTask<URL, Integer, StringBuilder> {

    private static final String TAG = makeLogTag(ApiDirectionsAsyncTask.class);

    private static final String DIRECTIONS_API_BASE = "https://maps.googleapis.com/maps/api/directions";
    private static final String OUT_JSON = "/json";

    // API KEY of the project Google Map Api For work
    private static final String API_KEY = "YOUR_API_KEY";

    @Override
    protected StringBuilder doInBackground(URL... params) {
        Log.i(TAG, "doInBackground of ApiDirectionsAsyncTask");

        HttpURLConnection mUrlConnection = null;
        StringBuilder mJsonResults = new StringBuilder();
        try {
            StringBuilder sb = new StringBuilder(DIRECTIONS_API_BASE + OUT_JSON);
            sb.append("?origin=" + URLEncoder.encode("Your origin address", "utf8"));
            sb.append("&destination=" + URLEncoder.encode("Your destination address", "utf8"));
            sb.append("&key=" + API_KEY);

            URL url = new URL(sb.toString());
            mUrlConnection = (HttpURLConnection) url.openConnection();
            InputStreamReader in = new InputStreamReader(mUrlConnection.getInputStream());

            // Load the results into a StringBuilder
            int read;
            char[] buff = new char[1024];
            while ((read = in.read(buff)) != -1){
                mJsonResults.append(buff, 0, read);
            }

        } catch (MalformedURLException e) {
            Log.e(TAG, "Error processing Distance Matrix API URL");
            return null;

        } catch (IOException e) {
            System.out.println("Error connecting to Distance Matrix");
            return null;
        } finally {
            if (mUrlConnection != null) {
                mUrlConnection.disconnect();
            }
        }

        return mJsonResults;
    }
}

希望对你有帮助！

Answer 3

只需检查以下链接。您可能会对此有所了解并自行尝试。

http://about-android.blogspot.in/2010/03/sample-google-map-driving-direction.html

您也可以使用 Google 距离矩阵 API

https://developers.google.com/maps/documentation/distancematrix/

Answer 4

String url = getDirectionsUrl(pickupLatLng, dropLatLng);
new GetDisDur().execute(url);

使用 latlng 创建 URL

private String getDirectionsUrl(LatLng origin, LatLng dest) {

        String str_origin = "origin=" + origin.latitude + "," + origin.longitude;

        String str_dest = "destination=" + dest.latitude + "," + dest.longitude;

        String sensor = "sensor=false";

        String mode = "mode=driving";

        String parameters = str_origin + "&" + str_dest + "&" + sensor + "&" + mode;

        String output = "json";

        return "https://maps.googleapis.com/maps/api/directions/" + output + "?" + parameters;
    }

类 GetDisDur

private class GetDisDur extends AsyncTask<String, String, String> {

        @Override
        protected String doInBackground(String... url) {

            String data = "";

            try {
                data = downloadUrl(url[0]);
            } catch (Exception e) {
                Log.d("Background Task", e.toString());
            }
            return data;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);

            try {
                JSONObject jsonObject = new JSONObject(result);

                JSONArray routes = jsonObject.getJSONArray("routes");

                JSONObject routes1 = routes.getJSONObject(0);

                JSONArray legs = routes1.getJSONArray("legs");

                JSONObject legs1 = legs.getJSONObject(0);

                JSONObject distance = legs1.getJSONObject("distance");

                JSONObject duration = legs1.getJSONObject("duration");

                distanceText = distance.getString("text");

                durationText = duration.getString("text");

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }