Попытка создать маршрут между двумя маркерами в Android Studio (с помощью Google Maps) - PullRequest
0 голосов
/ 23 апреля 2020

Я наткнулся на этот код: https://www.wingsquare.com/blog/drawing-driving-route-directions-between-two-locations-using-google-directions-in-google-map-android/?unapproved=76909&moderation-hash=19f6f2a68d83020034955fc1b89848b8#comment -76909

import androidx.fragment.app.FragmentActivity;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;

import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback{

    private GoogleMap mMap;
    private LatLng mOrigin;
    private LatLng mDestination;
    private Polyline mPolyline;
    ArrayList<LatLng> mMarkerPoints;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_maps);

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);

        mapFragment.getMapAsync(this);

        mMarkerPoints = new ArrayList<>();
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
            @Override
            public void onMapClick(LatLng point) {
                // Already two locations
                if(mMarkerPoints.size()>1){
                    mMarkerPoints.clear();
                    mMap.clear();
                }

                // Adding new item to the ArrayList
                mMarkerPoints.add(point);

                // Creating MarkerOptions
                MarkerOptions options = new MarkerOptions();

                // Setting the position of the marker
                options.position(point);

                /**
                 * For the start location, the color of marker is GREEN and
                 * for the end location, the color of marker is RED.
                 */
                if(mMarkerPoints.size()==1){
                    options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
                }else if(mMarkerPoints.size()==2){
                    options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
                }

                // Add new marker to the Google Map Android API V2
                mMap.addMarker(options);

                // Checks, whether start and end locations are captured
                if(mMarkerPoints.size() >= 2){
                    mOrigin = mMarkerPoints.get(0);
                    mDestination = mMarkerPoints.get(1);
                    drawRoute();
                }

            }
        });
    }

    private void drawRoute(){

        // Getting URL to the Google Directions API
        String url = getDirectionsUrl(mOrigin, mDestination);

        DownloadTask downloadTask = new DownloadTask();

        // Start downloading json data from Google Directions API
        downloadTask.execute(url);
    }


    private String getDirectionsUrl(LatLng origin,LatLng dest){

        // Origin of route
        String str_origin = "origin="+origin.latitude+","+origin.longitude;

        // Destination of route
        String str_dest = "destination="+dest.latitude+","+dest.longitude;

        // Key
        String key = "key=" + getString(R.string.google_maps_key);

        // Building the parameters to the web service
        String parameters = str_origin+"&amp;"+str_dest+"&amp;"+key;

        // Output format
        String output = "json";

        // Building the url to the web service
        String url = "https://maps.googleapis.com/maps/api/directions/"+output+"?"+parameters;

        return url;
    }

    /** A method to download json data from url */
    private String downloadUrl(String strUrl) throws IOException {
        String data = "";
        InputStream iStream = null;
        HttpURLConnection urlConnection = null;
        try{
            URL url = new URL(strUrl);

            // Creating an http connection to communicate with url
            urlConnection = (HttpURLConnection) url.openConnection();

            // Connecting to url
            urlConnection.connect();

            // Reading data from url
            iStream = urlConnection.getInputStream();

            BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

            StringBuffer sb  = new StringBuffer();

            String line = "";
            while( ( line = br.readLine())  != null){
                sb.append(line);
            }

            data = sb.toString();

            br.close();

        }catch(Exception e){
            Log.d("Exception on download", e.toString());
        }finally{
            iStream.close();
            urlConnection.disconnect();
        }
        return data;
    }

    /** A class to download data from Google Directions URL */
    private class DownloadTask extends AsyncTask<String, Void, String> {

        // Downloading data in non-ui thread
        @Override
        protected String doInBackground(String... url) {

            // For storing data from web service
            String data = "";

            try{
                // Fetching the data from web service
                data = downloadUrl(url[0]);
                Log.d("DownloadTask","DownloadTask : " + data);
            }catch(Exception e){
                Log.d("Background Task",e.toString());
            }
            return data;
        }

        // Executes in UI thread, after the execution of
        // doInBackground()
        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);

            ParserTask parserTask = new ParserTask();

            // Invokes the thread for parsing the JSON data
            parserTask.execute(result);
        }
    }

    /** A class to parse the Google Directions in JSON format */
    private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String,String>>> >{

        // Parsing the data in non-ui thread
        @Override
        protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {

            JSONObject jObject;
            List<List<HashMap<String, String>>> routes = null;

            try{
                jObject = new JSONObject(jsonData[0]);
                DirectionsJSONParser parser = new DirectionsJSONParser();

                // Starts parsing data
                routes = parser.parse(jObject);
            }catch(Exception e){
                e.printStackTrace();
            }
            return routes;
        }

        // Executes in UI thread, after the parsing process
        @Override
        protected void onPostExecute(List<List<HashMap<String, String>>> result) {
            ArrayList<LatLng> points = null;
            PolylineOptions lineOptions = null;

            // Traversing through all the routes
            for(int i=0;i<result.size();i++){
                points = new ArrayList<LatLng>();
                lineOptions = new PolylineOptions();

                // Fetching i-th route
                List<HashMap<String, String>> path = result.get(i);

                // Fetching all the points in i-th route
                for(int j=0;j<path.size();j++){
                    HashMap<String,String> point = path.get(j);

                    double lat = Double.parseDouble(point.get("lat"));
                    double lng = Double.parseDouble(point.get("lng"));
                    LatLng position = new LatLng(lat, lng);

                    points.add(position);
                }

                // Adding all the points in the route to LineOptions
                lineOptions.addAll(points);
                lineOptions.width(8);
                lineOptions.color(Color.RED);
            }

            // Drawing polyline in the Google Map for the i-th route
            if(lineOptions != null) {
                if(mPolyline != null){
                    mPolyline.remove();
                }
                mPolyline = mMap.addPolyline(lineOptions);

            }else
                Toast.makeText(getApplicationContext(),"No route is found", Toast.LENGTH_LONG).show();
        }
    }

}

Это кажется полезным, но каким-то образом оно дает мне это исключение, возникшее в строке 157 MapsActivity. class:

D/Exception on download: java.io.FileNotFoundException: https://maps.googleapis.com/maps/api/directions/json?origin=11.0,11.0&amp;destination=22.0,22.0&amp;key=(MyKey)

Кажется, что соединение url не работает, так как InputStream остается нулевым. Я подозреваю, что это ошибка 404, но кто-нибудь знает почему? Насколько я знаю, я активировал необходимые API.

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