private boolean hasPermissions(){
        int res = 0;
        //string array of permissions,
        String[] permissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};

        for (String perms : permissions){
            res = checkCallingOrSelfPermission(perms);
            if (!(res == PackageManager.PERMISSION_GRANTED)){
                return false;
            }
        }
        return true;
    }