如何在谷歌地图方向api v2中驾驶替代路线 [英] how to get driving alternative routes in google map direction api v2

问题描述

我只想在我的android应用中显示驾驶模式替代路线。我做了一条最短的路线，但我想要多条驾驶路线。

I just want to show driving mode alternative routes in my android app. I done a single shortest route but I want multiple driving routes.

我的代码在这里

My code is here

my mapsavtivity class

my mapsavtivity class

package com.example.sherazahmed.itis;
import android.content.Intent;
import android.graphics.Color;
import android.location.Location;
import android.os.AsyncTask;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
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.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
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;


public class onNotificationClick extends FragmentActivity implements       OnMapReadyCallback {

private GoogleMap mMap;
static LatLng current=new LatLng(0,0);
       static LatLng destination=new LatLng(0,0);

public void onNotificationClick(LatLng current,LatLng destination){
    this.current=current;
    this.destination=destination;

}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_on_notification_click);
    // 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);
}
@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.addMarker(new MarkerOptions().position(current).title("current location"));
    mMap.addMarker(new MarkerOptions().position(destination).title("destination"));

    DownloadTask downloadTask;
    String url=null;
    String mode = "mode=driving";
    String mode1 = "mode=bicycling";
    String mode2 = "mode=walking";
   url = getDirectionsUrl(current, destination,mode);
    downloadTask=new DownloadTask();
// Start downloading json data from Google Directions API
    downloadTask.execute(url);

    //2
    url = getDirectionsUrl(current, destination,mode2);
    downloadTask=new DownloadTask();
// Start downloading json data from Google Directions API
    downloadTask.execute(url);

    //3
    url = getDirectionsUrl(current, destination,mode1);
    downloadTask=new DownloadTask();
// Start downloading json data from Google Directions API
    downloadTask.execute(url);






}

private String getDirectionsUrl(LatLng origin,LatLng dest, String mode){

    // 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";
        String alter="Alternative=true";
    // Travelling Mode


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

    // 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 =new String();
    InputStream iStream = new InputStream() {
        @Override
        public int read() throws IOException {
            return 0;
        }
    };
    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 in down 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 =new String();
        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 = new ArrayList<LatLng>();
        PolylineOptions lineOptions = new PolylineOptions();


        // 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(4);

            // Changing the color polyline according to the mode

        }

        if(result.size()<1){
            Toast.makeText(getBaseContext(), "No Points", Toast.LENGTH_SHORT).show();
            return;
        }

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

DirectionJSONParser类

DirectionJSONParser class

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 

推荐答案

String alter="Alternatives=true";

是做这件事的方法，我忘记把
s放入在上面的代码替代！
干杯！

is the way to do this thing, i just forgot to place "s" in alternative in above code ! cheers !

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