Kotlin version

internal class RetrieveFeedTask : AsyncTask<String, Void, RSSFeed>() {

    override fun doInBackground(vararg urls: String): RSSFeed? {

        try {
             // download
             // prepare RSSFeeds
             return RSSFeeds

         } catch (e: Exception) {

            //handle exception
            return null
        }
    }

    override fun onPostExecute(feed: RSSFeed) {
        // TODO: check this.exception
        // TODO: do something with the feed
    }
}

Call example,

RetrieveFeedTask().execute(url)