Android Issue Drawing Long Routes on MapView using XML Parsing_问答_开发者

I have problem occuring in my application.. Using XML file i am getting geopoints to draw the path between two locations..but it only shows me the route if the distance is less than 300 kilometers .. otherwise it doesnt draw full path..

any solution for dividing the xml file in chunks..or any alternatives..because the directions it gives are perfect even for long distance...then what the problem is ?? i cant understand..

please help..

EDITED : I have Found that there is a problem in KML file. If there is a long Distance it is providing two line string tag each having co-ordinates list of full path divided into parts. as follows

<GeometryCollection>

<LineString>

<coordinates>70.799640,22.283370,...</coordinates> </LineString>

<LineString>

<coordinates>73.005940,21.536300,....</coordinates> </LineString>

</GeometryCollection>

thats why it will draw a Route on map only of the second half of the String.. so.. anybody know how to solve this..

EDITED :-

public class DrivingDirectionsGoogleKML extends DrivingDirections
{
    @Override
    protected void startDrivingTo (GeoPoint startPoint, GeoPoint endPoint, Mode mode, IDirectionsListener listener)
    {
        new LoadDirectionsTask(startPoint, endPoint).execute(mode);
    }

    private class LoadDirectionsTask extends AsyncTask<Mode, Void, RouteImpl>
    {
        private static final String BASE_URL = "http://maps.google.com/maps?f=d&hl=en";
        private static final String ELEMENT_PLA开发者_如何学编程CEMARK = "Placemark";
        private static final String ELEMENT_NAME = "name";
        private static final String ELEMENT_DESC = "description";
        private static final String ELEMENT_POINT = "Point";
        private static final String ELEMENT_ROUTE = "Route";
        private static final String ELEMENT_GEOM = "GeometryCollection";

        private GeoPoint startPoint;
        private GeoPoint endPoint;

        public LoadDirectionsTask (GeoPoint startPoint, GeoPoint endPoint)
        {
            this.startPoint = startPoint;
            this.endPoint = endPoint;
        }

        @Override
        protected void onPreExecute() 
        {
            super.onPreExecute();
        }

        @Override
        protected RouteImpl doInBackground(Mode... params)
        {
            // Connect to the Google Maps web service that will return a KML string
            // containing the directions from one point to another.
            //
            StringBuilder urlString = new StringBuilder();
            urlString
                .append(BASE_URL)
                .append("&saddr=")
                .append(startPoint.getLatitudeE6() / 1E6)
                .append(",")
                .append(startPoint.getLongitudeE6() / 1E6)
                .append("&daddr=")
                .append(endPoint.getLatitudeE6() / 1E6)
                .append(",")
                .append(endPoint.getLongitudeE6() / 1E6)
                .append("&ie=UTF8&0&om=0&output=kml");

            if (params[0] == Mode.WALKING) 
            {
                urlString.append("&dirflg=w");
            }

            RouteImpl route = null;
            try 
            {
                URL url = new URL (urlString.toString());

                Log.i("-------- Url",url.toString());

                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                connection.setDoOutput(true);
                connection.setDoInput(true);
                connection.connect();

                route = parseResponse (connection.getInputStream()); 
            }
            catch (Exception e) 
            {
                route = null;
            }

            return route;
        }

        private RouteImpl parseResponse(InputStream inputStream) throws Exception
        {
            // Parse the KML file returned by the Google Maps web service
            // using the default XML DOM parser.
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.parse(inputStream);         
            NodeList placemarkList = document.getElementsByTagName(ELEMENT_PLACEMARK);

            // Get the list of placemarks to plot along the route.
            List<Placemark> placemarks = new ArrayList<Placemark>();
            for (int i = 0; i < placemarkList.getLength(); i++)
            {
                PlacemarkImpl placemark = parsePlacemark (placemarkList.item(i));
                if (placemark != null) {
                    placemarks.add(placemark);
                }
            }

            // Get the route defining the driving directions.
            RouteImpl route = parseRoute (placemarkList);
            route.setPlacemarks(placemarks);
            return route;
        }

        private PlacemarkImpl parsePlacemark(Node item)
        {
            PlacemarkImpl placemark = new PlacemarkImpl ();

            boolean isRouteElement = false;
            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);
                if (node.getNodeName().equals(ELEMENT_NAME)) 
                {
                    String name = node.getFirstChild().getNodeValue();
                    if (name.equals(ELEMENT_ROUTE)) 
                    {
                        isRouteElement = true;
                    }
                    else 
                    {
                        isRouteElement = false;
                        placemark.setInstructions(name);
                    }
                }
                else if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    if (!isRouteElement) 
                    {
                        String distance = node.getFirstChild().getNodeValue();
                        placemark.setDistance(distance.substring(3).replace("&#160;", " "));
                    }
                }
                else if (node.getNodeName().equals(ELEMENT_POINT)) 
                {
                    if (!isRouteElement) 
                    {
                        String coords = node.getFirstChild().getFirstChild().getNodeValue();
                        String[] latlon = coords.split(",");
                        placemark.setLocation(new GeoPoint ((int) (Double.parseDouble(latlon[1]) * 1E6),(int) (Double.parseDouble(latlon[0]) * 1E6)));
                    }
                }
            }
            return isRouteElement ? null : placemark;
        }

        private RouteImpl parseRoute(NodeList placemarkList)
        {
            RouteImpl route = null;

            for (int i = 0; i < placemarkList.getLength(); i++)
            {
                // Iterate through all the <Placemark> KML tags to find the one
                // whose child <name> tag is "Route".
                //
                Node item = placemarkList.item(i);
                NodeList children = item.getChildNodes();
                for (int j = 0; j < children.getLength(); j++)
                {
                    Node node = children.item(j);
                    if (node.getNodeName().equals(ELEMENT_NAME))
                    {
                        String name = node.getFirstChild().getNodeValue();
                        if (name.equals(ELEMENT_ROUTE))
                        {
                            route = parseRoute (item);
                            break;
                        }
                    }
                }
            }
            return route;
        }

        private RouteImpl parseRoute(Node item)
        {
            RouteImpl route = new RouteImpl ();

            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);

                if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    // Get the value of the <description> KML tag.
                    String distance = node.getFirstChild().getNodeValue();
                    route.setTotalDistance(distance.split("<br/>")[0].substring(10).replace("&#160;", " "));
                }
                else if (node.getNodeName().equals(ELEMENT_GEOM)) //Here Reading Co-Ordinates..///
                {

                    String path = node.getFirstChild().getFirstChild().getFirstChild().getNodeValue();
                    String[] pairs = path.split(" ");

                    // For each coordinate, get its {latitude, longitude} values and add the corresponding geographical point to the route.

                    List<GeoPoint> geoPoints = new ArrayList<GeoPoint>();
                    for (int p = 0; p < pairs.length; p++) 
                    {
                        String[] coords = pairs[p].split(",");
                        GeoPoint geoPoint = new GeoPoint ((int) (Double.parseDouble(coords[1]) * 1E6),(int) (Double.parseDouble(coords[0]) * 1E6));
                        geoPoints.add (geoPoint);
                    }
                    route.setGeoPoints(geoPoints);

                }
            }

            return route;
        }

        protected void onPostExecute (RouteImpl route)
        {
            if (route == null) 
            {
                DrivingDirectionsGoogleKML.this.onDirectionsNotAvailable();
            }
            else 
            {
                DrivingDirectionsGoogleKML.this.onDirectionsAvailable(route); 
            }
        }
    }
}

I have Found Solution For it.. Created NodeList of <GeometryCollection>....</GeometryCollection> and it will provide all co-ordinates between two locations..

private RouteImpl parseRoute(Node item)
        {
            RouteImpl route = new RouteImpl ();
            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);

                if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    // Get the value of the <description> KML tag.
                    //
                    String distance = node.getFirstChild().getNodeValue();
                    route.setTotalDistance(distance.split("<br/>")[0].substring(10).replace("&#160;", " "));
                }
                else if (node.getNodeName().equals(ELEMENT_GEOM)) 
                {
                    // Get the space-separated coordinates of the geographical points defining the route.
                    //

                    List<GeoPoint> geoPoints = new ArrayList<GeoPoint>();

                                    // Create a NodeList  here ..
                    NodeList geoMetryChildren = node.getChildNodes();

                    for(int k=0;k<geoMetryChildren.getLength();k++)
                    {
                        Node geoMetryChildrenNode = geoMetryChildren.item(k);
                        String path = geoMetryChildrenNode.getFirstChild().getFirstChild().getNodeValue();

                        String[] pairs = path.split(" ");

                        for (int p = 0; p < pairs.length; p++) 
                        {
                            String[] coords = pairs[p].split(",");
                            GeoPoint geoPoint = new GeoPoint ((int) (Double.parseDouble(coords[1]) * 1E6),(int) (Double.parseDouble(coords[0]) * 1E6));
                            geoPoints.add (geoPoint);
                        }
                    }
                    route.setGeoPoints(geoPoints);
                }
            }

            return route;
        }