How can you tell when an Android device has a Geocoder backend service?

问题

According to the Geocoder documentation, the class provides methods into a backend service which may or may not exist on the device. If the geocoder doesn't exist on the device, theoretically a geocode request will return no results. However, how can one differentiate between no results due to there being no backend geocoder service vs. there being no results because the location makes no sense?

My app already requires the Google Maps API, so perhaps this is a moot point; as a secondary question, does the Google Maps API always include a Geocoder?

回答1:

According to the Google Maps docs, "The Google Maps API provides a client geocoder for geocoding addresses". So I would say that since you are requiring the google maps API, you are requiring a geocoder.

回答2:

Strictly speaking there could be another backend installed, just try if a geocoder is present

    final Geocoder geocoder = new Geocoder(this);
    final String locName = "1600 Amphitheatre Parkway, Mountain View, CA";
    try {
        final List<Address> list = geocoder.getFromLocationName(locName, 1);
        if ( ! (list == null || list.isEmpty()) ) {
            final Address address = list.get(0);
            System.out.println("Geocoder backend present, (lat,lon) = (" + address.getLatitude() + ", " + address.getLongitude() + ")");
        }
        else {
            System.out.println("Geocoder backend not present");
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

来源：https://stackoverflow.com/questions/2255020/how-can-you-tell-when-an-android-device-has-a-geocoder-backend-service