Android: automatically choose debug/release Maps api key?

Question

Is it possible to automatically detect, which certificate was used for signing APK? I'd like to have both debug and release Maps certificates in application and pass valid one to MapView constructor.

With such setup I will not make mistake while releasing application - I'm using debug certificate on emulator and my device, then sign with release one before sending app to Market.

I was thinking about detecting my particular device or whether debugger is connected but it is not perfect. Maybe some file marking need for debug certificate? Is there any better way?

Answer 1

I've ended up with the special file on SD card - if present, use debug key; missing - use release one. And it works.

EDIT: see new accepted answer, it works better

Answer 2

You might find the answer provided here suitable as well.

Answer 3

Had the same hassle with the API key. Here's a full solution, based on the above link and example from Bijarni (which somehow didn't work for me), I use now this method:

// Define the debug signature hash (Android default debug cert). Code from sigs[i].hashCode()
protected final static int DEBUG_SIGNATURE_HASH = <your hash value>;

// Checks if this apk was built using the debug certificate
// Used e.g. for Google Maps API key determination (from: http://whereblogger.klaki.net/2009/10/choosing-android-maps-api-key-at-run.html)
public static Boolean isDebugBuild(Context context) {
    if (_isDebugBuild == null) {
        try {
            _isDebugBuild = false;
            Signature [] sigs = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
            for (int i = 0; i < sigs.length; i++) {
                if (sigs[i].hashCode() == DEBUG_SIGNATURE_HASH) {
                    Log.d(TAG, "This is a debug build!");
                    _isDebugBuild = true;
                    break;
                }
            }
        } catch (NameNotFoundException e) {
            e.printStackTrace();
        }      
    }
    return _isDebugBuild;
}

You have to find out your debug signature's hashValue() once, just output sigs[i].hashCode().

Then, I didn't want to dynamically add the MapView, but rather use the xml file. You cannot set the api key attribute in the code and use an xml layout, so I use this simple method (though copying the xml layout isn't so beautiful):

In my MapActivity:

    public void onCreate(Bundle savedInstanceState)
    {       
    super.onCreate(savedInstanceState);

    // Select the proper xml layout file which includes the matching Google API Key
    if (isDebugBuild(this)) {
        setContentView(R.layout.map_activity_debug);
    } else {
        setContentView(R.layout.map_activity_release);
    }