Android convert CID location to Coordinates

Question

I built an android app which can handle a share intent from Google Maps and show it's coordinates.

The problem is that they send a short url which I decode with Google's url shortner api and in some cases, the result long link is of this type: http://maps.google.com/?cid=3635533832900933072&hl=en&gl=us.

Can anyone help me on how to get the coresponding coordinates to "cid=3635533832900933072"

Answer 1

As far as I know there is no public API to get the location from a cid.

However, a possible workaround would be to parse the Google Maps output to obtain the latitude and longitude (though it may be brittle, if they change the result format).

(Although the url contains output=json, it's not actually json -- that's why I parse it with substring() and such instead of using JSONObject).

Try this code:

public static LatLng getCidCoordinates(String cid)
{
    final String URL_FORMAT = "http://maps.google.com/maps?cid=%s&q=a&output=json"; 
    final String LATLNG_BEFORE = "viewport:{center:{";
    final String LATLNG_AFTER = "}";
    final String LATLNG_SEPARATOR = ",";
    final String LAT_PREFIX = "lat:";
    final String LNG_PREFIX = "lng:";

    try
    {
        HttpClient client = new DefaultHttpClient();
        HttpGet get = new HttpGet(String.format(URL_FORMAT, cid));
        HttpResponse response = client.execute(get);

        String text = EntityUtils.toString(response.getEntity(), "UTF-8");

        int startIndex = text.indexOf(LATLNG_BEFORE);
        if (startIndex == -1)
            return null;

        startIndex += LATLNG_BEFORE.length();
        int endIndex = text.indexOf(LATLNG_AFTER, startIndex);

        // Should be "lat:<number>,lng:<number>"
        String[] parts = text.substring(startIndex, endIndex).split(LATLNG_SEPARATOR);
        if (parts.length != 2)
            return null;

        if (parts[0].startsWith(LAT_PREFIX))
            parts[0] = parts[0].substring(LAT_PREFIX.length());
        else
            return null;

        if (parts[1].startsWith(LNG_PREFIX))
            parts[1] = parts[1].substring(LNG_PREFIX.length());
        else
            return null;

        return new LatLng(Double.parseDouble(parts[0]), Double.parseDouble(parts[1]));
    }
    catch (NumberFormatException e)
    {
        e.printStackTrace();
        return null;
    }
    catch (IOException e)
    {
        e.printStackTrace();
        return null;
    }
}

Answer 2

After reading this post yesterday, I found a new method to do it. I hope Google do not close this new API and hidden parameter. :)

You can use this API hidden parameter to get the coordinater. Usage: https://maps.googleapis.com/maps/api/place/details/json?cid=YOUR_CID&key=YOUR_KEY

It returns a result contains formatted address, place_id, name of the address and GPS coordinater.

Please see my blog to see more detail: https://leonbbs.blogspot.com/2018/03/google-map-cid-to-placeid-or-get.html

Answer 3

In latest Google Maps update, the share intent contains the address name in the body which can be decoded with Geocoder into coordinates.