从goole map API解析json数据失败

Question

我想得到纬度和经度，我想使用AsyncTask，但我看不到日志值，它不能正常工作

我想错过哪一步？任何帮助都会感激不尽。

我的全局变量：

double editLatitude, editLongitude;

@Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {


        View view = inflater.inflate(R.layout.traffic_information_fragment, container, false);


        mapFrag = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map);
        mapFrag.getMapAsync(this);
        //it's my json url----------------------------------------------    
        new TrafficInformationTask().execute("http://maps.googleapis.com/maps/api/geocode/json?address=國泰綜合醫院+TW=true_or_false");

        return view;

    }

它是我的AsyncTask：

public class TrafficInformationTask extends AsyncTask<String, Integer, String> {
        @Override
        protected String doInBackground(String... strings) {
            String url = strings[0];
            try {
                String routeJson = getRoute(url);
                return routeJson;
            } catch (IOException ex) {
                Log.d(TAG, ex.toString());
            }
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            showRoute(s);
        }
    }


    private String getRoute(String url) throws IOException {
        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        int responseCode = connection.getResponseCode();
        StringBuilder jsonIn = new StringBuilder();
        if (responseCode == 200) {
            BufferedReader bf = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while ((line = bf.readLine()) != null) {
                jsonIn.append(line);
            }
        } else {
            Log.d(TAG, responseCode + "responseCode");
        }
        connection.disconnect();
        Log.d(TAG, jsonIn + "jsonIn");
        return jsonIn.toString();
    }
    //it's my parse step
    private void showRoute(String route) {
        try {
            JSONObject jsonObject = new JSONObject(route);
            JSONArray resultsArray = jsonObject.getJSONArray("results");
            JSONObject zeroJson = resultsArray.getJSONObject(0);
            JSONObject geometryJson = zeroJson.getJSONObject("geometry");
            editLatitude = geometryJson.getJSONObject("location").getDouble("lat");
            editLongitude = geometryJson.getJSONObject("location").getDouble("lng");
            //there is no value from log
            Log.d("editLatitude",editLatitude+"");
            Log.d("editLongitude",editLongitude+"");

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

Answer 1

您可以使用Geocoder（https://developer.android.com/reference/android/location/Geocoder.html）获取经度

 public void Get_LatLng(){
    if(Geocoder.isPresent()){
        try {
            String location = "your_location_name";
            Geocoder gc = new Geocoder(this);
            List<Address> addresses= gc.getFromLocationName(location, 5); // get the Address Objects

            List<LatLng> ll = new ArrayList<LatLng>(addresses.size()); // A list to save the coordinates if they are available
            for(Address ad : addresses){
                if(ad.hasLatitude() && ad.hasLongitude()){
                    ll.add(new LatLng(ad.getLatitude(), ad.getLongitude()));
                    Log.d("editLatitude",ad.getLatitude());
                    Log.d("editLongitude",ad.getLongitude());
                }  
            }  
        } catch (IOException e) {
             // handle the exception
        }
    }
}

在某些情况下，

Geocoder可能会返回null。这可能是一个问题

您可以将HTTP request与Google地图apis一起使用latitude longitude

使用以下代码：

 private class TrafficInformationTask extends AsyncTask<String, Void, String[]> {
   ProgressDialog dialog = new ProgressDialog(MainActivity.this);
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        dialog.setMessage("Loading..");
        dialog.setCanceledOnTouchOutside(false);
        dialog.show();
    }

    @Override
    protected String[] doInBackground(String... params) {
        String response;
        try {
            response = getLatLongByURL("http://maps.google.com/maps/api/geocode/json?address=dhaka&sensor=false");
            Log.d("response",""+response);
            return new String[]{response};
        } catch (Exception e) {
            return new String[]{"error"};
        }
    }

    @Override
    protected void onPostExecute(String... result) {
        try {
            JSONObject jsonObject = new JSONObject(result[0]);

            double lng = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
                    .getJSONObject("geometry").getJSONObject("location")
                    .getDouble("lng");

            double lat = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
                    .getJSONObject("geometry").getJSONObject("location")
                    .getDouble("lat");

            Log.d("latitude", "" + lat);
            Log.d("longitude", "" + lng);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        if (dialog.isShowing()) {
            dialog.dismiss();
        }
    }
}


public String getLatLongByURL(String requestURL) {
    URL url;
    String response = "";
    try {
        url = new URL(requestURL);

        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(15000);
        conn.setConnectTimeout(15000);
        conn.setRequestMethod("GET");
        conn.setDoInput(true);
        conn.setRequestProperty("Content-Type",
                "application/x-www-form-urlencoded");
        conn.setDoOutput(true);
        int responseCode = conn.getResponseCode();

        if (responseCode == HttpsURLConnection.HTTP_OK) {
            String line;
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            while ((line = br.readLine()) != null) {
                response += line;
            }
        } else {
            response = "";
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
    return response;
}