在Android中使用Directions API显示多条路线

Question

我正在使用这个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个备用路线.即使服务器响应有多条路由,它也只解析第一条路由并显示它.我应该做些什么更改才能显示google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中解析它,否则您可以使用以下方法将InputStream转换为String:

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;
        }
    }

那么你将不得不将响应解析为JSONObject

JSONObject jSONObject = new JSONObject(string);

然后你得到JSONArray命名路由

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

现在,您可以通过从JSONArray获取索引来开始从每个路由获取数据.

我写了一段代码作为路线的模型

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;
    }

关于步骤图像,有一个HTML指令和另一个称为机动的字段,根据该字段,您将选择您的图像

我希望这有帮助 ;)