Unknown exception caught in Moving Work from the Main Thread to an AsyncTask

protected String[] mBlogPostTitles;
public static final int NUMBER_OF_POSTS = 20;
public static final String TAG = MainListActivity.class.getSimpleName();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_list);

    GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
    getBlogPostsTask.execute();
    //Toast.makeText(this, getString(R.string.no_items), Toast.LENGTH_LONG).show();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main_list, menu);
    return true;
}

private class GetBlogPostsTask extends AsyncTask<Object, Void, String>{

    @Override
    protected String doInBackground(Object... arg0) {
        int responceCode = -1;

        try {
        URL blogFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count=" + NUMBER_OF_POSTS);
        HttpsURLConnection connection = (HttpsURLConnection) blogFeedUrl.openConnection();
        connection.connect();

        responceCode = connection.getResponseCode();
        Log.i(TAG, "Code: " + responceCode);
    }
    catch (MalformedURLException e) {
        Log.e(TAG, "Exception caught: ", e);
    }
    catch (IOException e) {
        Log.e(TAG, "Exception caught: ", e);
    }
    catch (Exception e) {
        Log.e(TAG, "Exception caught: ", e);
    }
        return "code: " + responceCode;

    }

}