如何從 JSON Web 服務獲取緯度和經度？

Question

我正在將字符串格式的Country Name轉換為Longitude 和 Latitude 。

為此，我正在使用以下JSON Web 服務。

https://maps.googleapis.com/maps/api/geocode/json?address=India&sensor=true

我不知道如何從 JSON 中獲取經度和緯度。

請幫助我從上述 Web 服務中獲取經度和緯度。

我試過下面的代碼，但我不確定它是否正確：

try 
{
                    Log.v("MAPS","Lang-Lat::1");
                    String myjsonstring = stringBuffer.toString();
                    Log.v("My JSON STRING",""+myjsonstring);
                    Log.v("MAPS","Lang-Lat::2");    
                    JSONArray jsonArray = new JSONArray(myjsonstring);

                    Log.v("MAPS","Lang-Lat::3");
                    JSONObject jsonObj = null;

                    String status = jsonObj.getString("status");
                    Log.v("MAPS","Lang-Lat::4");
                    if (status.equals("OK")) 
                    {
                        Log.v("Log Receive","Json String:::"+myjsonstring);                 

                        jsonObj = jsonArray.getJSONObject(0);

                        JSONObject JSONObject2=jsonObj.getJSONObject("geometry");

                        JSONObject JSONObject3=JSONObject2.getJSONObject("bounds");

                        JSONObject JSONObject4=JSONObject3.getJSONObject("northeast");

                        for(int i=0; i<JSONObject4.length();i++)
                        {
                            lang = JSONObject4.getDouble("lng");
                            lat=JSONObject4.getDouble("lat");

                            Log.v("Lang:",""+lang);
                            Log.v("Lat",""+lat);

                        }
                    }
                } 
                catch (Exception e) 
                {
                    Log.v("Map_View::","Call JSON Exception in Getting Map--->"+e.toString());
                    e.printStackTrace();
                }

任何幫助將不勝感激。

先感謝您。

Answer 1

public class ParseLatitudeLng {

    public static JSONObject getLocationInfo(String address) {
        StringBuilder stringBuilder = new StringBuilder();
        try {

        address = address.replaceAll(" ","%20");    

        HttpPost httppost = new HttpPost("http://maps.google.com/maps/api/geocode/json?address=" + address + "&sensor=false");
        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());
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return jsonObject;
    }

}

/ * ** * ** * *從地址獲取緯度和經度* ** * ** * ** /

public class GetLatLngAsyncTask extends AsyncTask<ArrayList<String>, Void, String>{

        JSONObject jObject;
        JSONObject places = null;
        String lat;


        protected void onPreExecute() {

        }
        @Override
        protected String doInBackground(ArrayList<String>... params) {
            //ParseLatitudeLng placeJsonParser = new ParseLatitudeLng();
            ArrayList<String> inSync=params[0];

            double lng1 = 0,lat1 = 0;

            try{
                    lng1=lat1=0;


                    places = ParseLatitudeLng.getLocationInfo(YOUR_ADDRESS);
                    lng1 = ((JSONArray)places.get("results")).getJSONObject(0)
                            .getJSONObject("geometry").getJSONObject("location")
                            .getDouble("lng");

                    lat1 = ((JSONArray)places.get("results")).getJSONObject(0)
                            .getJSONObject("geometry").getJSONObject("location")
                            .getDouble("lat");



                }catch(Exception e){
                    Log.d("Exception",e.toString());
                }


            return lat;
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);


        }

    }

調用 Asynctask 獲取緯度和經度