android, permission, in code

Activity act = ...
if (act.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
    Toast.makeText(getContext(), "Permission is granted", Toast.LENGTH_LONG).show();
}else{
    Toast.makeText(getContext(), "Permission is not granted", Toast.LENGTH_LONG).show();

    ActivityCompat.requestPermissions(act, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}

ref : https://toepic.fail/안드로이드-마쉬멜로우-버전-이상에서-권한처리하기-95527b99aafb