Put this code into your onCreate() method
try {
PackageInfo info = getPackageManager().getPackageInfo(
getPackageName(),
PackageManager.GET_SIGNATURES);
for (android.content.pm.Signature signature : info.signatures) {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(signature.toByteArray());
Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
}
}
catch (PackageManager.NameNotFoundException e) {
}
catch (NoSuchAlgorithmException e) {
}
Note: Please run signed application otherwise you might get wrong Key