Google Map Androidスタジオの複数のウェイポイントを持つ2つの場所の間の最善のルート

Question

私は2つのロケーションポイント間で最良のソートパスを見ることができるAndroidスタジオアプリケーションを作っています。私は通常のアンドロイドのスタジオの地図フレームとSupportMapFragmentを使用してGoogleマップを表示します。私は複数のwaypoints.Theseは、私のアンドロイドアプリケーションのファイルです。このプロジェクトファイルのMapsActivity.javaファイルgetmapメソッドの1つの問題のみが機能していません。これを開発する他の方法はありますか？

public class MapsActivity extends FragmentActivity { 

     GoogleMap map; 
     ArrayList<LatLng> markerPoints; 

     @Override 
     protected void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_maps); 

      // Initializing 
      markerPoints = new ArrayList<LatLng>(); 

      // Getting reference to SupportMapFragment of the activity_main 
      SupportMapFragment fm = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map); 

      // Getting reference to Button 
      Button btnDraw = (Button)findViewById(R.id.btn_draw); 

      // Getting Map for the SupportMapFragment 
      map = fm.getMap(); 

      // Enable MyLocation Button in the Map 
      map.setMyLocationEnabled(true); 

      // Setting onclick event listener for the map 
      map.setOnMapClickListener(new GoogleMap.OnMapClickListener() { 

       @Override 
       public void onMapClick(LatLng point) { 

        // Already 10 locations with 8 waypoints and 1 start location and 1 end location. 
        // Upto 8 waypoints are allowed in a query for non-business users 
        if(markerPoints.size()>=10){ 
         return; 
        } 

        // Adding new item to the ArrayList 
        markerPoints.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 and 
        * for the rest of markers, the color is AZURE 
        */ 
        if(markerPoints.size()==1){ 
         options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)); 
        }else if(markerPoints.size()==2){ 
         options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED)); 
        }else{ 
         options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)); 
        } 

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

      // The map will be cleared on long click 
      map.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener() { 

       @Override 
       public void onMapLongClick(LatLng point) { 
        // Removes all the points from Google Map 
        map.clear(); 

        // Removes all the points in the ArrayList 
        markerPoints.clear(); 
       } 
      }); 

      // Click event handler for Button btn_draw 
      btnDraw.setOnClickListener(new View.OnClickListener() { 

       @Override 
       public void onClick(View v) { 
        // Checks, whether start and end locations are captured 
        if(markerPoints.size() >= 2){ 
         LatLng origin = markerPoints.get(0); 
         LatLng dest = markerPoints.get(1); 

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

         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; 

      // Sensor enabled 
      String sensor = "sensor=false"; 

      // Waypoints 
      String waypoints = ""; 
      for(int i=2;i<markerPoints.size();i++){ 
       LatLng point = (LatLng) markerPoints.get(i); 
       if(i==2) 
        waypoints = "waypoints="; 
       waypoints += point.latitude + "," + point.longitude + "|"; 
      } 

      // Building the parameters to the web service 
      String parameters = str_origin+"&"+str_dest+"&"+sensor+"&"+waypoints; 

      // 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 while downloading url", e.toString()); 
      }finally{ 
       iStream.close(); 
       urlConnection.disconnect(); 
      } 
      return data; 
     } 

     // Fetches data from url passed 
     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]); 
       }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 Places 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(2); 
        lineOptions.color(Color.RED); 
       } 

       // Drawing polyline in the Google Map for the i-th route 
       map.addPolyline(lineOptions); 
      } 
     } 
     } 

他のファイルDirectionsJSONParser.java

public class DirectionsJSONParser { 

    /** 
    * Receives a JSONObject and returns a list of lists containing latitude and longitude 
    */ 
    public List<List<HashMap<String, String>>> parse(JSONObject jObject) { 

     List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String, String>>>(); 
     JSONArray jRoutes = null; 
     JSONArray jLegs = null; 
     JSONArray jSteps = null; 

     try { 

      jRoutes = jObject.getJSONArray("routes"); 

      /** Traversing all routes */ 
      for (int i = 0; i < jRoutes.length(); i++) { 
       jLegs = ((JSONObject) jRoutes.get(i)).getJSONArray("legs"); 
       List path = new ArrayList<HashMap<String, String>>(); 

       /** Traversing all legs */ 
       for (int j = 0; j < jLegs.length(); j++) { 
        jSteps = ((JSONObject) jLegs.get(j)).getJSONArray("steps"); 

        /** Traversing all steps */ 
        for (int k = 0; k < jSteps.length(); k++) { 
         String polyline = ""; 
         polyline = (String) ((JSONObject) ((JSONObject) jSteps.get(k)).get("polyline")).get("points"); 
         List<LatLng> list = decodePoly(polyline); 

         /** Traversing all points */ 
         for (int l = 0; l < list.size(); l++) { 
          HashMap<String, String> hm = new HashMap<String, String>(); 
          hm.put("lat", Double.toString(((LatLng) list.get(l)).latitude)); 
          hm.put("lng", Double.toString(((LatLng) list.get(l)).longitude)); 
          path.add(hm); 
         } 
        } 
        routes.add(path); 
       } 
      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } catch (Exception e) { 
     } 
     return routes; 
    } 

    /** 
    * Method to decode polyline points 
    * Courtesy : jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java 
    */ 
    private List<LatLng> decodePoly(String encoded) { 

     List<LatLng> poly = new ArrayList<LatLng>(); 
     int index = 0, len = encoded.length(); 
     int lat = 0, lng = 0; 

     while (index < len) { 
      int b, shift = 0, result = 0; 
      do { 
       b = encoded.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 = encoded.charAt(index++) - 63; 
       result |= (b & 0x1f) << shift; 
       shift += 5; 
      } while (b >= 0x20); 
      int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1)); 
      lng += dlng; 

      LatLng p = new LatLng((((double) lat/1E5)), 
        (((double) lng/1E5))); 
      poly.add(p); 
     } 

     return poly; 
    } 
} 

マップを取得するために

<RelativeLayout 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
> 

<Button 
    android:id="@+id/btn_draw" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:layout_alignParentBottom="true" 
    android:layout_centerHorizontal="true" /> 

<fragment 
    android:id="@+id/map" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_above="@id/btn_draw" /> 

</RelativeLayout> 

Answer 1

activity_maps.xml他のファイル、この使用：あなたの活動はOnMapReadyCallbackを実装する必要があります

// 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); 

をとo Verride onMapReady(GoogleMap googleMap)機能。

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback{ 
    ..... 

@Override 
public void onMapReady(GoogleMap googleMap) { 
    mMap = googleMap; 

    } 

} 

Getting Startedを参照してください。