Blogreader error

protected String [] mBlogPostsTitles;
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);

    if(isNetworkAvailable()){

    GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
    getBlogPostsTask.execute();
    }

    else{
        Toast.makeText(this, "The network is currently Unavailable." , Toast.LENGTH_LONG).show();
    }
}

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 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... params) 
        {
            int responseCode = -1; 
            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();
            Log.i(TAG, "Code: " + responseCode);
            }
        catch(MalformedURLException e)
            {
                Log.e(TAG, "Exception Found: ", e);
            }
        catch(IOException e)
            {
                Log.e(TAG, "Exception Found: " ,e);
            }
        catch(Exception e)
        {
            Log.e(TAG, "Exception Found: ", e);
        }
            return "Code: " +responseCode;
        }

    }

@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);
}