在 Android 中使用 Directions API 显示多条路线

Question

我正在使用此类在地图上显示路线。问题是它只显示一条路线。我想要做的是在地图上显示多条备用路线。即使服务器响应有多个路由，它也只解析第一个路由并显示它。我应该做些什么改变来显示谷歌服务器返回的所有路由。这是我的课程。

public class GMapV2Direction {
    public final static String MODE_DRIVING = "driving";
    public final static String MODE = "walking";
    public final static String MODE_WALKING = "walking";

    public GMapV2Direction() { }

    public Document getDocument(LatLng start, LatLng end, String mode) {
        String url = "http://maps.googleapis.com/maps/api/directions/xml?" 
                + "origin=" + start.latitude + "," + start.longitude  
                + "&destination=" + end.latitude + "," + end.longitude 
                + "&sensor=false&units=metric&mode="+MODE+"alternatives=true";

        try {
            HttpClient httpClient = new DefaultHttpClient();
            HttpContext localContext = new BasicHttpContext();
            HttpPost httpPost = new HttpPost(url);
            HttpResponse response = httpClient.execute(httpPost, localContext);
            InputStream in = response.getEntity().getContent();
            DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document doc = builder.parse(in);
            return doc;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public String getDurationText (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("duration");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "text"));
        Log.i("DurationText", node2.getTextContent());
        return node2.getTextContent();
    }

    public int getDurationValue (Document doc) {

        NodeList nl1 = doc.getElementsByTagName("duration");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "value"));
        Log.i("DurationValue", node2.getTextContent());
        return Integer.parseInt(node2.getTextContent());

    }

    public String getDistanceText (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("distance");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "text"));
        Log.i("DistanceText", node2.getTextContent());
        return node2.getTextContent();
    }

    public int getDistanceValue (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("distance");
        Node node1 = nl1.item(0);
        NodeList nl2 = node1.getChildNodes();
        Node node2 = nl2.item(getNodeIndex(nl2, "value"));
        Log.i("DistanceValue", node2.getTextContent());
        return Integer.parseInt(node2.getTextContent());
    }

    public String getStartAddress (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("start_address");
        Node node1 = nl1.item(0);
        Log.i("StartAddress", node1.getTextContent());
        return node1.getTextContent();
    }

    public String getEndAddress (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("end_address");
        Node node1 = nl1.item(0);
        Log.i("EndAddress", node1.getTextContent());
        return node1.getTextContent();
    }

    public String getCopyRights (Document doc) {
        NodeList nl1 = doc.getElementsByTagName("copyrights");
        Node node1 = nl1.item(0);
        Log.i("CopyRights", node1.getTextContent());
        return node1.getTextContent();
    }

    public ArrayList<LatLng> getDirection (Document doc) {
        NodeList nl1, nl2, nl3;
        ArrayList<LatLng> listGeopoints = new ArrayList<LatLng>();
        nl1 = doc.getElementsByTagName("step");
        if (nl1.getLength() > 0) {
            for (int i = 0; i < nl1.getLength(); i++) {
                Node node1 = nl1.item(i);
                nl2 = node1.getChildNodes();

                Node locationNode = nl2.item(getNodeIndex(nl2, "start_location"));
                nl3 = locationNode.getChildNodes();
                Node latNode = nl3.item(getNodeIndex(nl3, "lat"));
                double lat = Double.parseDouble(latNode.getTextContent());
                Node lngNode = nl3.item(getNodeIndex(nl3, "lng"));
                double lng = Double.parseDouble(lngNode.getTextContent());
                listGeopoints.add(new LatLng(lat, lng));

                locationNode = nl2.item(getNodeIndex(nl2, "polyline"));
                nl3 = locationNode.getChildNodes();
                latNode = nl3.item(getNodeIndex(nl3, "points"));
                ArrayList<LatLng> arr = decodePoly(latNode.getTextContent());
                for(int j = 0 ; j < arr.size() ; j++) {
                    listGeopoints.add(new LatLng(arr.get(j).latitude, arr.get(j).longitude));
                }

                locationNode = nl2.item(getNodeIndex(nl2, "end_location"));
                nl3 = locationNode.getChildNodes();
                latNode = nl3.item(getNodeIndex(nl3, "lat"));
                lat = Double.parseDouble(latNode.getTextContent());
                lngNode = nl3.item(getNodeIndex(nl3, "lng"));
                lng = Double.parseDouble(lngNode.getTextContent());
                listGeopoints.add(new LatLng(lat, lng));
            }
        }

        return listGeopoints;
    }

    private int getNodeIndex(NodeList nl, String nodename) {
        for(int i = 0 ; i < nl.getLength() ; i++) {
            if(nl.item(i).getNodeName().equals(nodename))
                return i;
        }
        return -1;
    }

    private ArrayList<LatLng> decodePoly(String encoded) {
        ArrayList<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 position = new LatLng((double) lat / 1E5, (double) lng / 1E5);
            poly.add(position);
        }
        return poly;
    }
}

Answer 1

我认为您不必获取 Google Server 的响应并在 Document 中对其进行解析，否则您可以从 InputStream 进行转换> 到 String 使用：

private String convertStreamToString(final InputStream input) throws Exception {
    try {
        final BufferedReader reader = new BufferedReader(new InputStreamReader(input));
        final StringBuffer sBuf = new StringBuffer();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sBuf.append(line);
        }
        return sBuf.toString();
    } catch (Exception e) {
        throw e;
    } finally {
        try {
            input.close();
        } catch (Exception e) {
            throw e;
        }
    }

那么您必须将响应解析为 JSONObject

JSONObject jSONObject = new JSONObject(string);

然后你会得到名为 routes

的 JSONArray

JSONArray routeJSONArray = jSONObject.getJSONArray("routes");

现在您可以通过从 JSONArray 获取其索引来开始从每个路由中获取数据。

我已经编写了一段 sn-p 代码作为路由的模型

Route.java

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import android.content.Context;

import com.google.android.gms.maps.model.Polyline;

public class Route implements Serializable {

    private static final long serialVersionUID = 1L;
    private Bound bounds;
    private String copyrights;
    private List<Leg> legs;
    private Polyline overviewPolyLine;
    private String summary;

    public Route(Context context) {
        legs = new ArrayList<Leg>();
    }

    public Bound getBounds() {
        return bounds;
    }

    public void setBounds(Bound bounds) {
        this.bounds = bounds;
    }

    public String getCopyrights() {
        return copyrights;
    }

    public void setCopyrights(String copyrights) {
        this.copyrights = copyrights;
    }

    public List<Leg> getLegs() {
        return legs;
    }

    public void setLegs(List<Leg> legs) {
        this.legs = legs;
    }

    public void addLeg(Leg leg) {
        this.legs.add(leg);
    }

    public Polyline getOverviewPolyLine() {
        return overviewPolyLine;
    }

    public void setOverviewPolyLine(Polyline overviewPolyLine) {
        this.overviewPolyLine = overviewPolyLine;
    }

    public String getSummary() {
        return summary;
    }

    public void setSummary(String summary) {
        this.summary = summary;
    }

    public static long getSerialversionuid() {
        return serialVersionUID;
    }

}

Bound.java

import com.google.android.gms.maps.model.LatLng;

public class Bound {
    private LatLng northEast;
    private LatLng southWest;
    public LatLng getNorthEast() {
        return northEast;
    }
    public void setNorthEast(LatLng northEast) {
        this.northEast = northEast;
    }
    public LatLng getSouthWest() {
        return southWest;
    }
    public void setSouthWest(LatLng southWest) {
        this.southWest = southWest;
    }
}

Leg.java

import java.util.ArrayList;
import java.util.List;

import com.google.android.gms.maps.model.LatLng;

public class Leg {
    private Distance distance;
    private Duration duration;
    private String endAddress;
    private LatLng endLocation;
    private String startAddress;
    private LatLng startLocation;
    private List<Step> steps;

    public Leg() {
        steps = new ArrayList<Step>();
    }

    public Distance getDistance() {
        return distance;
    }

    public void setDistance(Distance distance) {
        this.distance = distance;
    }

    public Duration getDuration() {
        return duration;
    }

    public void setDuration(Duration duration) {
        this.duration = duration;
    }

    public String getEndAddress() {
        return endAddress;
    }

    public void setEndAddress(String endAddress) {
        this.endAddress = endAddress;
    }

    public LatLng getEndLocation() {
        return endLocation;
    }

    public void setEndLocation(LatLng endLocation) {
        this.endLocation = endLocation;
    }

    public String getStartAddress() {
        return startAddress;
    }

    public void setStartAddress(String startAddress) {
        this.startAddress = startAddress;
    }

    public LatLng getStartLocation() {
        return startLocation;
    }

    public void setStartLocation(LatLng startLocation) {
        this.startLocation = startLocation;
    }

    public List<Step> getSteps() {
        return steps;
    }

    public void setSteps(List<Step> steps) {
        this.steps = steps;
    }

    public void addStep(Step step) {
        this.steps.add(step);
    }

}

Distance.java

public class Distance {
    private String text;
    private long value;

    public Distance(String text, long value) {
        this.text = text;
        this.value = value;
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }

    public long getValue() {
        return value;
    }

    public void setValue(long value) {
        this.value = value;
    }

}

Duration.java

public class Duration {
    public Duration(String text, long value) {
        this.text = text;
        this.value = value;
    }

    private String text;
    private long value;

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }

    public long getValue() {
        return value;
    }

    public void setValue(long value) {
        this.value = value;
    }

}

Step.java

import java.util.List;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.drawable.Drawable;

import com.google.android.gms.maps.model.LatLng;
import com.nweave.etaxi.driver.R;

public class Step {
    private Distance distance;
    private Duration duration;
    private LatLng endLocation;
    private LatLng startLocation;
    private String htmlInstructions;
    private String travelMode;
    private List<LatLng> points;

    public List<LatLng> getPoints() {
        return points;
    }

    public void setPoints(List<LatLng> points) {
        this.points = points;
    }

    public Distance getDistance() {
        return distance;
    }

    public void setDistance(Distance distance) {
        this.distance = distance;
    }

    public Duration getDuration() {
        return duration;
    }

    public void setDuration(Duration duration) {
        this.duration = duration;
    }

    public LatLng getEndLocation() {
        return endLocation;
    }

    public void setEndLocation(LatLng endLocation) {
        this.endLocation = endLocation;
    }

    public LatLng getStartLocation() {
        return startLocation;
    }

    public void setStartLocation(LatLng startLocation) {
        this.startLocation = startLocation;
    }

    public String getHtmlInstructions() {
        return htmlInstructions;
    }

    public void setHtmlInstructions(String htmlInstructions) {
        this.htmlInstructions = htmlInstructions;
    }

    public String getTravelMode() {
        return travelMode;
    }

    public void setTravelMode(String travelMode) {
        this.travelMode = travelMode;
    }
}

解析函数将是

public List<Route> parse(String routesJSONString) throws Exception {
    try {
        List<Route> routeList = new ArrayList<Route>();
        final JSONObject jSONObject = new JSONObject(routesJSONString);
        JSONArray routeJSONArray = jSONObject.getJSONArray(ROUTES);
        Route route;
        JSONObject routesJSONObject;
        for (int m = 0; m < routeJSONArray.length(); m++) {
            route = new Route(context);
            routesJSONObject = routeJSONArray.getJSONObject(m);
            JSONArray legsJSONArray;
            route.setSummary(routesJSONObject.getString(SUMMARY));
            legsJSONArray = routesJSONObject.getJSONArray(LEGS);
            JSONObject legJSONObject;
            Leg leg;
            JSONArray stepsJSONArray;
            for (int b = 0; b < legsJSONArray.length(); b++) {
                leg = new Leg();
                legJSONObject = legsJSONArray.getJSONObject(b);
                leg.setDistance(new Distance(legJSONObject.optJSONObject(DISTANCE).optString(TEXT), legJSONObject.optJSONObject(DISTANCE).optLong(VALUE)));
                leg.setDuration(new Duration(legJSONObject.optJSONObject(DURATION).optString(TEXT), legJSONObject.optJSONObject(DURATION).optLong(VALUE)));
                stepsJSONArray = legJSONObject.getJSONArray(STEPS);
                JSONObject stepJSONObject, stepDurationJSONObject, legPolyLineJSONObject, stepStartLocationJSONObject, stepEndLocationJSONObject;
                Step step;
                String encodedString;
                LatLng stepStartLocationLatLng, stepEndLocationLatLng;
                for (int i = 0; i < stepsJSONArray.length(); i++) {
                    stepJSONObject = stepsJSONArray.getJSONObject(i);
                    step = new Step();
                    JSONObject stepDistanceJSONObject = stepJSONObject.getJSONObject(DISTANCE);
                    step.setDistance(new Distance(stepDistanceJSONObject.getString(TEXT), stepDistanceJSONObject.getLong(VALUE)));
                    stepDurationJSONObject = stepJSONObject.getJSONObject(DURATION);
                    step.setDuration(new Duration(stepDurationJSONObject.getString(TEXT), stepDurationJSONObject.getLong(VALUE)));
                    stepEndLocationJSONObject = stepJSONObject.getJSONObject(END_LOCATION);
                    stepEndLocationLatLng = new LatLng(stepEndLocationJSONObject.getDouble(LATITUDE), stepEndLocationJSONObject.getDouble(LONGITUDE));
                    step.setEndLocation(stepEndLocationLatLng);
                    step.setHtmlInstructions(stepJSONObject.getString(HTML_INSTRUCTION));
                    legPolyLineJSONObject = stepJSONObject.getJSONObject(POLYLINE);
                    encodedString = legPolyLineJSONObject.getString(POINTS);
                    step.setPoints(decodePolyLines(encodedString));
                    stepStartLocationJSONObject = stepJSONObject.getJSONObject(START_LOCATION);
                    stepStartLocationLatLng = new LatLng(stepStartLocationJSONObject.getDouble(LATITUDE), stepStartLocationJSONObject.getDouble(LONGITUDE));
                    step.setStartLocation(stepStartLocationLatLng);
                    leg.addStep(step);
                }
                route.addLeg(leg);
            }
            routeList.add(route);
        }
        return routeList;
    } catch (Exception e) {
        throw e;
    }

关于 Step Image 有一个 HTML 指令和另一个名为 ma​​neuver 的字段，您将根据该字段选择您的图像

我希望这会有所帮助；）

Answer 2

我认为你可以这样做

LatLng origin = sourcePosition;
     LatLng dest = destPosition;

  DownloadTask1 downloadTask = new DownloadTask1();
  String url = downloadTask.getDirectionsUrl1(origin, dest);                   
  downloadTask.execute(url);

DownloadTask1 类

 private class DownloadTask1 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);

            ParserTask1 parserTask = new ParserTask1();

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


        private String getDirectionsUrl1(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&alternatives=true&units=metric&mode=driving";
            //&alternatives=true&units=metric&mode=driving
            // Building the parameters to the web service
            String parameters = str_origin + "&" + str_dest + "&" + sensor;

            // 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;
        }
    }

downloadUrl() 方法

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

ParserTask1 类

private class ParserTask1 extends AsyncTask<String, Integer, List<List<List<HashMap<String, String>>>>> {

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

            JSONObject jObject;
            List<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<List<HashMap<String, String>>>> result) {
            ArrayList<LatLng> points = null;
            PolylineOptions lineOptions = new PolylineOptions();

            PolylineOptions lineOptions1 = null;
            MarkerOptions markerOptions = new MarkerOptions();
            String distance = "";
            String duration = "";

            Integer size1 = 0;
            Integer size2 = 0;
            Integer size3 = 0;
//            Log.d(SHETTY, "onPostExecute: result set "+result.size());


            List<LatLng> aline1 = new ArrayList<LatLng>();
            List<LatLng> aline2 = new ArrayList<LatLng>();
            List<LatLng> aline3 = new ArrayList<LatLng>();


            if (result != null) {
                int i = 0;
                Log.d(SHETTY, "onPostExecute: result size " + result.size());

                while (i < result.size()) {

                    //  for(int i=0;i<result.size();i++){
                    //result.size()
                    //int g= i-1;
                    points = new ArrayList<LatLng>();
                    // lineOptions = new PolylineOptions();
                    // if(i==1){

                    // }else{
                    List<List<HashMap<String, String>>> path1 = result.get(i);

                    for (int s = 0; s < path1.size(); s++) {
                        Log.d("pathsize1", path1.size() + "");

                        // Fetching i-th route
                        List<HashMap<String, String>> path = path1.get(s);
                        Log.d("pathsize", path.size() + "");
                        // Fetching all the points in i-th route

                        for (int j = 0; j < path.size(); j++) {
                            lineOptions1 = new PolylineOptions();
                            HashMap<String, String> point = path.get(j);
                            //  points = new ArrayList<LatLng>();
                            //                    if(j==0){    // Get distance from the list
                            //                        distance = (String)point.get("distance");
                            //                        continue;
                            //                    }else if(j==1){ // Get duration from the list
                            //                        duration = (String)point.get("duration");
                            //                        continue;
                            //                    }
                            double lat = Double.parseDouble(point.get("lat"));
                            double lng = Double.parseDouble(point.get("lng"));
                            LatLng position = new LatLng(lat, lng);
                            // Log.d("latlng", position.toString());
                            points.add(position);


                        }
                        //                lineOptions.addAll(points);
                        //                lineOptions.width(5);
                        //                lineOptions.color(Color.BLUE);
                        //                map.addPolyline(lineOptions);

                    }
                    // }
                    if (i == 0) {


//                        line1.addAll(points);
//                        mMap.addPolyline(line1);

                        size1 = points.size();

                        aline1.addAll(points);
                    } else if (i == 1) {


//                        line2.addAll(points);
//                        mMap.addPolyline(line2);

                        aline2.addAll(points);
                        size2 = points.size();
                    } else if (i == 2) {


//                        line3.addAll(points);
//                        mMap.addPolyline(line3);

                        aline3.addAll(points);
                        size3 = points.size();
                    }
                    // Adding all the points in the route to LineOptions
                    i++;


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

            if (size3 != 0)
            {

                if ((size1 > size2 && size1 > size3)) {
                    if (size2 > size3) {
                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);

                        mMap.addPolyline(line1);
                        mMap.addPolyline(line2);
                        mMap.addPolyline(line3);


                        Log.d(SHETTY, "onPostExecute: 3110 ");
                    } else {

                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);

                        mMap.addPolyline(line1);
                        mMap.addPolyline(line3);

                        mMap.addPolyline(line2);


                        Log.d(SHETTY, "onPostExecute: 3127 ");
                    }
                } else if ((size2 > size1 && size2 > size3)) {
                    if (size1 > size3) {
                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);

                        mMap.addPolyline(line1);
                        mMap.addPolyline(line2);

                        mMap.addPolyline(line3);


                        Log.d(SHETTY, "onPostExecute: 3147 ");
                    } else {

                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);


                        mMap.addPolyline(line2);
                        mMap.addPolyline(line3);

                        mMap.addPolyline(line1);

                        Log.d(SHETTY, "onPostExecute: 3164 ");
                    }
                } else if ((size3 > size1 && size3 > size2)) {
                    if (size1 > size2) {
                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);


                        mMap.addPolyline(line3);
                        mMap.addPolyline(line1);
                        mMap.addPolyline(line2);

                        Log.d(SHETTY, "onPostExecute: 3182 ");
                    } else {
                        PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                        PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                        PolylineOptions line3 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));

                        line1.addAll(aline1);
                        line2.addAll(aline2);
                        line3.addAll(aline3);

                        mMap.addPolyline(line3);
                        mMap.addPolyline(line2);

                        mMap.addPolyline(line1);

                        Log.d(SHETTY, "onPostExecute: 3196 ");
                    }
                } else {
                    System.out.println("ERROR!");
                }

        }else if(size2!=0)
            {
                if(size1>size2){

                    PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));
                    PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));


                    line1.addAll(aline1);
                    line2.addAll(aline2);

                    mMap.addPolyline(line1);
                    mMap.addPolyline(line2);

                }else
                {
                    PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                    PolylineOptions line2 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.grey));

                    line1.addAll(aline1);
                    line2.addAll(aline2);

                    mMap.addPolyline(line2);
                    mMap.addPolyline(line1);
                }



            }
            else if(size1!=0){
                PolylineOptions line1 = new PolylineOptions().width(8).color(getActivity().getResources().getColor(R.color.lightblue));
                line1.addAll(aline1);
                mMap.addPolyline(line1);
            }

        }




        }

现在为解析 JObject 创建 DirectionsJSONParser 类

public class DirectionsJSONParser {

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

        List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String,String>>>() ;
        List<List<List<HashMap<String,String>>>> routes1 = new ArrayList<List<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>>();
                List path1 = new ArrayList<ArrayList<HashMap<String,String>>>();

                // Log.d("legs",jLegs.toString());
                /** Traversing all legs */
                for(int j=0;j<jLegs.length();j++){
                    HashMap<String, String> hm1 = new HashMap<String, String>();
                    jSteps = ( (JSONObject)jLegs.get(j)).getJSONArray("steps");
                    // Log.d("steps",jSteps.toString());
                    /** 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);
                        //  Log.d("polyline",polyline.toString());
                        /** 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);
                            //  Log.d("lat", Double.toString(((LatLng)list.get(l)).latitude));
                            //  Log.d("lng", Double.toString(((LatLng)list.get(l)).longitude));
                        }

                    }

                    path1.add(path);

                }
                routes1.add(path1);
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }catch (Exception e){
        }

        return routes1;
    }
    /**
     * Method to decode polyline points
     * Courtesy : http://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;
    }

}

最后，您将获得蓝色的主要路线和灰色的替代路线。希望对您有所帮助。

Answer 3

这应该可行。在我的应用程序上测试。

protected void onPostExecute(String s) {
    try {
        JSONObject jsonObject = new JSONObject(s);
        JSONArray jsonArrayRoute = jsonObject.getJSONArray("routes");
        JSONObject jsonObjectRoute;
        int route =  jsonArrayRoute.length();
            for (int m = 0; m < route; m++) {
                jsonObjectRoute = jsonArrayRoute.getJSONObject(m);
                JSONArray jsonArrayLegs;
                jsonArrayLegs = jsonObjectRoute.getJSONArray("legs");
                JSONObject jsonObjectLegs;
                JSONArray jsonArraySteps;
                for (int b = 0; b < jsonArrayLegs.length(); b++) {
                    jsonObjectLegs = jsonArrayLegs.getJSONObject(b);
                    jsonArraySteps = jsonObjectLegs.getJSONArray("steps");
                    JSONObject jsonObjectSteps, jsonObjectLegPolyline;
                    String[] polylineArray = new String[jsonArraySteps.length()];
                    for (int i = 0; i < jsonArraySteps.length(); i++) {
                        jsonObjectSteps = jsonArraySteps.getJSONObject(i);
                        jsonObjectLegPolyline = jsonObjectSteps.getJSONObject("polyline");
                        String polygone = jsonObjectLegPolyline.getString("points");
                        polylineArray[i] = polygone;
                    }
                    int count2 = polylineArray.length;
                    for (int i = 0; i < count2; i++) {
                        mGoogleMap.addPolyline((new PolylineOptions())
                                .color(Color.BLUE)
                                .width(10)
                                .clickable(true)
                                .addAll(PolyUtil.decode(polylineArray[i])));
                    }
                }
        } catch (JSONException e) {
        e.printStackTrace();
    }
}