Android版Google Mapsアプリの「共有」メニューから送られてくるIntentの短縮URLから、緯度経度を調べる

README.md

GoogleMapsの共有用短縮URLから緯度経度を調べる

• google mapsの短縮URL(http://goo.gl/maps/czrYDなど)から緯度経度を調べる
• Android版Mapsアプリの「共有」メニュー(Intent)から得られるURLが対象
  • Webブラウザ版mapから得られる短縮URLにはcidが無いので無理
• RubyとAndroid Java版を実装した

動作

• 短縮URLにHEADリクエストしてlocationヘッダからリダイレクト先を取得
• リダイレクト先のcidパラメータを取得
• cidパラメータを使って http://maps.google.com/maps?cid=#{cid}&hl=ja&output=json にGETリクエスト
• centerプロパティ内のlat(緯度)とlng(経度)を取得

参考

• google api - Android convert CID location to Coordinates - Stack Overflow

MIT License

gmap_getlatlon.rb

#!/usr/bin/env ruby
# google mapsの短縮URLから緯度経度を調べる
# AndroidのIntentで得られるURLが対象
# Web版mapから得られるURLにはcidが無いので無理

require 'net/http'
require 'uri'

def get_latlon(uri)
  if uri.class == URI::HTTPS
    http = Net::HTTP.new uri.host, 443
    http.use_ssl = true
  else
    http = Net::HTTP.new uri.host, uri.port
  end
  res = http.request Net::HTTP::Head.new uri.request_uri
  redirect_to = URI.parse res['location']

  return nil unless redirect_to.path == '/'

  cid = redirect_to.query.split('&').map{|i| i.split '=' }.find{|i| i[0] == 'cid' }[1]

  uri = URI.parse "http://maps.google.com/maps?cid=#{cid}&hl=ja&output=json"
  http = Net::HTTP.new uri.host, 443
  http.use_ssl = true
  res = http.request Net::HTTP::Get.new uri.request_uri
  lat,lon = res.body.scan(/viewport:{center:{lat:(\-?[\d\.]+),lng:(\-?[\d\.]+)}/)[0]
  return {:cid => cid, :lat => lat, :lon => lon}
end

if __FILE__ == $0
  uri = URI.parse ARGV.shift || "http://goo.gl/maps/czrYD"
  puts "get lat/lon of #{uri}"
  res = get_latlon uri
  p res
end

GMapUtil.java

// google mapsの短縮URLから緯度経度を調べる
// AndroidのGoogleMapの「共有」から得られるURLが対象
// Web版mapから得られるURLにはcidが無いので無理
// GMapUtil.getLocation(Intent, Callback); から使う
// MIT License

package org.shokai.gmapstars;

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.HttpURLConnection;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class GMapUtil {

    public static final String TAG = "GMapUtil";

    public static class Location{
        public double latitude;
        public double longitude;
        public String name;
        public URL url;
        public String cid;
        public String toString(){
            return name+" "+url.toString()+" [lat:"+latitude+",lon:"+longitude+",cid:"+cid+"]";
        }
    }

    public interface LocationCallback {
        void onSuccess(Location location);
        void onError(Exception ex);
    }

    public static void getLocation(Intent intent, final LocationCallback callback){
        if(intent == null){
            callback.onError(new Exception("intent is null"));
            return;
        }
        if(!intent.getAction().equals(Intent.ACTION_SEND)){
            callback.onError(new Exception("invalid intent"));
            return;
        }
        final Location location = new Location();

        Bundle extras = intent.getExtras();
        location.name = extras.getString(Intent.EXTRA_SUBJECT); // 地名
        String text = extras.getString(Intent.EXTRA_TEXT);
        getLocationFromIntentText(text, new LocationCallback() {
            @Override
            public void onSuccess(Location _location) {
                location.url = _location.url;
                location.latitude = _location.latitude;
                location.longitude = _location.longitude;
                location.cid = _location.cid;
                callback.onSuccess(location);
            }

            @Override
            public void onError(Exception ex) {
                callback.onError(ex);
            }
        });
    }

    public static void getLocationFromIntentText(String text, final LocationCallback callback){
        final Location location = new Location();
        URL shortUrl;
        try {
            shortUrl = getUrlFromIntentText(text);
        }
        catch (Exception ex){
            callback.onError(ex);
            return;
        }
        location.url = shortUrl;

        new GetCidFromShortUrlTask(new GetCidFromShortUrlTask.Callback() {
            @Override
            public void onSuccess(String cid) {
                location.cid = cid;
                new GetLocationFromCidTask(new GetLocationFromCidTask.Callback() {
                    @Override
                    public void onSuccess(Location _location) {
                        location.longitude = _location.longitude;
                        location.latitude = _location.latitude;
                        callback.onSuccess(location);
                    }

                    @Override
                    public void onError(Exception ex) {
                        callback.onError(ex);
                    }
                }).execute(cid);
            }

            @Override
            public void onError(Exception ex) {
                callback.onError(ex);
            }
        }).execute(shortUrl);
    }

    public static URL getUrlFromIntentText(String text) throws MalformedURLException{
        Matcher m = Pattern.compile("\\s+(https?://[^\\s]+)$").matcher(text);
        if (m.find()) return new URL(m.group(1));
        return null;
    }

    public static class GetCidFromShortUrlTask extends AsyncTask<URL, Void, String>{

        public interface Callback{
            void onSuccess(String cid);
            void onError(Exception ex);
        }

        private Callback callback;

        public GetCidFromShortUrlTask(Callback callback){
            super();
            this.callback = callback;
        }

        protected String doInBackground(URL... args) {
            URL shortUrl = args[0];
            try {
                HttpURLConnection http = (HttpURLConnection) shortUrl.openConnection();
                http.setRequestMethod("HEAD");
                http.setInstanceFollowRedirects(false);
                http.connect();
                String redirectTo = http.getHeaderField("location");
                Matcher m = Pattern.compile("cid=(\\d+)").matcher(redirectTo);
                if(m.find()) return m.group(1);
            }
            catch(Exception ex){
                Log.e(TAG, ex.getMessage());
                if(callback != null) callback.onError(ex);
            }
            return null;
        }

        @Override
        protected void onPostExecute(String cid) {
            if(callback == null) return;
            if(cid == null) {
                callback.onError(new Exception("cannot find cid"));
                return;
            }
            callback.onSuccess(cid);
        }
    }

    public static class GetLocationFromCidTask extends AsyncTask<String, Void, Location>{

        public interface Callback{
            void onSuccess(Location location);
            void onError(Exception ex);
        }

        private Callback callback;

        public GetLocationFromCidTask(Callback callback){
            super();
            this.callback = callback;
        }

        protected Location doInBackground(String... args){
            String cid = args[0];
            final Location location = new Location();
            try{
                URL url = new URL("https://maps.google.com/maps?cid="+cid+"&hl=ja&output=json");
                HttpURLConnection http = (HttpURLConnection) url.openConnection();
                http.setRequestMethod("GET");
                http.connect();

                int code = http.getResponseCode();
                if(code != 200){
                    if(callback != null) callback.onError(new Exception("status code is "+code));
                    return null;
                }
                char[] buf = new char[1024];
                new InputStreamReader(http.getInputStream(), "UTF-8").read(buf);
                String body = new String(buf);

                Matcher m = Pattern.compile("lat:(\\-?[\\d\\.]+),lng:(\\-?[\\d\\.]+)").matcher(body);
                if(m.find()){
                    location.latitude = Double.parseDouble(m.group(1));
                    location.longitude = Double.parseDouble(m.group(2));
                    return location;
                }
            }
            catch (Exception ex){
                Log.e(TAG, ex.getMessage());
                if(callback != null) callback.onError(ex);
            }
            return null;
        }

        @Override
        protected void onPostExecute(Location location){
            if(callback == null) return;
            if(location == null){
                callback.onError(new Exception("cannot get location"));
                return;
            }
            callback.onSuccess(location);
        }
    }
}

こんにちは、はじめまして
GMapUtil.javaをプロジェクトに取り込んでみましたがうまく行きませんでした。
私が投稿しました以下のURLを確認していただけないでしょうか。
https://teratail.com/questions/134912
以上、よろしくお願いいたします。