안드로이드 Java 액티비티에서 KeyHash 확인하기

try {
    PackageInfo info = getPackageManager().getPackageInfo(
            getPackageName(), PackageManager.GET_SIGNATURES);
    for (Signature signature : info.signatures) {
        MessageDigest md = MessageDigest.getInstance("SHA");
        md.update(signature.toByteArray());
        String hash = Base64.encodeToString(md.digest(), Base64.DEFAULT);
        Log.d("KeyHash:", hash);
    }
} catch (NameNotFoundException e) {
    Log.e("name not found", e.toString());
} catch (NoSuchAlgorithmException e) {
    Log.e("no such an algorithm", e.toString());
}