App can't connect to the blog after doing "Opening a Webpage in Browser" class.

public class MainListActivity extends ListActivity {

    public static final int NUMBER_OF_POSTS = 20;
    public static final String TAG = MainListActivity.class.getSimpleName();
    protected JSONObject mBlogData;
    protected ProgressBar mProgressBar;

    private final String KEY_TITLE = "title";
    private final String KEY_AUTHOR = "author";

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

        mProgressBar = (ProgressBar) findViewById(R.id.progressBar1);

        if (isNetworkAvailable()) {
            mProgressBar.setVisibility(View.VISIBLE);
            GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
            getBlogPostsTask.execute();
        }
        else {
            Toast.makeText(this, "Network is unavailable!", Toast.LENGTH_LONG).show();
        }

        //String message = getString(R.string.no_items);
        //Toast.makeText(this, message, Toast.LENGTH_LONG).show();


    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        try {
            JSONArray jsonPosts = mBlogData.getJSONArray("posts");
            JSONObject jsonPost = jsonPosts.getJSONObject(position);
            String blogUrl = jsonPost.getString("url");
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setData(Uri.parse(blogUrl));
            startActivity(intent);
        } catch (JSONException e) {
            logException(e);
        }
    }

    private void logException(Exception e) {
        Log.e(TAG, "exception caught!", e);
    }

    private boolean isNetworkAvailable() {
        ConnectivityManager manager = (ConnectivityManager) 
                getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkinfo = manager.getActiveNetworkInfo();

        boolean isAvailable = false;
        if(networkinfo != null && networkinfo.isConnected()) {
            isAvailable = true;
        }
        return isAvailable; 
    }



    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }


    public void handleBlogResponse() {
        mProgressBar.setVisibility(View.INVISIBLE);
        if (mBlogData == null) {
            updateDisplayForError();
        }
        else {
            try {
                JSONArray jsonPosts = mBlogData.getJSONArray("posts");
                ArrayList<HashMap<String, String>> blogPosts = 
                        new ArrayList<HashMap<String, String>>();
                for (int i = 0; i < jsonPosts.length(); i++) {
                    JSONObject post = jsonPosts.getJSONObject(i);
                    String title = post.getString(KEY_TITLE);
                    title = Html.fromHtml(title).toString();
                    String author = post.getString(KEY_AUTHOR);
                    author = Html.fromHtml(author).toString();

                    HashMap<String, String> blogPost = new HashMap<String, String>();
                    blogPost.put(KEY_TITLE, title);
                    blogPost.put(KEY_AUTHOR, author);

                    blogPosts.add(blogPost);

                }

                String[] keys = {KEY_TITLE, KEY_AUTHOR};
                int[] ids = {android.R.id.text1, android.R.id.text2 };
                SimpleAdapter adapter = 
                        new SimpleAdapter(this, blogPosts, android.R.layout.simple_list_item_2, keys, ids);
                setListAdapter(adapter);
            }
            catch (JSONException e) {
                Log.e(TAG, "Exception caught!", e);
            }
        }

    }

    private void updateDisplayForError() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle(getString(R.string.title));
        builder.setMessage(getString(R.string.Error_message));
        builder.setPositiveButton(android.R.string.ok, null);
        AlertDialog dialog = builder.create();
        dialog.show();

        TextView emptyTextView = (TextView) getListView().getEmptyView();
        emptyTextView.setText(getString(R.string.no_items));
        //TODO: Handle error
    }

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

        @Override
        protected JSONObject doInBackground(Object... params) {
            int responseCode = -1;
            JSONObject jsonResponse = null;

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

            responseCode = connection.getResponseCode();
            if(responseCode == HttpURLConnection.HTTP_OK){
                InputStream inputstream = connection.getInputStream();
                Reader reader = new InputStreamReader(inputstream);
                int contentLength = connection.getContentLength();
                char[] charArray = new char[contentLength];
                reader.read(charArray);
                String responseData = new String(charArray);

                jsonResponse = new JSONObject(responseData);
            }
            else {
                Log.i(TAG, "Unsuccessful HTTP Response Code: " + responseCode);
            }


            }
            catch(MalformedURLException e) {
                logException(e);
            } 
            catch (IOException e) {
                logException(e);
            } 
            catch (Exception e) {
                logException(e);
            }

            return jsonResponse;
        }

        @Override
        protected void onPostExecute(JSONObject result) {
            mBlogData = result;
            handleBlogResponse();
        }

    }


}