listview and http request SIMPLE in android

MainActivity.java

import android.content.Context;
import android.net.ConnectivityManager;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;


public class MainActivity extends AppCompatActivity {


    ListView listado;

    public static String [] nombres = {
            "Let Us C",
            "c++",
            "JAVA",
            "Jsp",
            "Microsoft .Net",
            "Let Us C",
            "c++",
            "JAVA",
            "Jsp",
            "Microsoft .Net",
            "Microsoft .Net",
            "Microsoft .Net",
    };

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

        // call AsynTask to perform network operation on separate thread
        new HttpAsyncTask().execute("http://hmkcode.appspot.com/rest/controller/get.json");
    }

    public static String GET(String url){
        InputStream inputStream = null;
        String result = "";
        try {

            // create HttpClient
            HttpClient httpclient = new DefaultHttpClient();

            // make GET request to the given URL
            HttpResponse httpResponse = httpclient.execute(new HttpGet(url));

            // receive response as inputStream
            inputStream = httpResponse.getEntity().getContent();

            // convert inputstream to string
            if(inputStream != null)
                result = convertInputStreamToString(inputStream);
            else
                result = "Did not work!";

        } catch (Exception e) {
            Log.d("InputStream", e.getLocalizedMessage());
        }

        return result;
    }

    private static String convertInputStreamToString(InputStream inputStream) throws IOException {
        BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
        String line = "";
        String result = "";
        while((line = bufferedReader.readLine()) != null)
            result += line;

        inputStream.close();
        return result;

    }


    private class HttpAsyncTask extends AsyncTask<String, String, String> {
        @Override
        protected String doInBackground(String... urls) {

            return GET(urls[0]);
        }

        // onPostExecute displays the results of the AsyncTask.
        @Override
        protected void onPostExecute(String result) {
            Toast.makeText(getBaseContext(), "Received!", Toast.LENGTH_LONG).show();
            System.out.println(result);
            try {
                JSONObject json = new JSONObject(result); // convert String to JSONObject
                JSONArray articles = json.getJSONArray("articleList"); // get articles array

                String titulos[];
                titulos = new String[articles.length()];
                for (int i = 0; i < articles.length(); i++) {
                    System.out.println(articles.getJSONObject(i).get("title"));
                    titulos[i] = articles.getJSONObject(i).get("title").toString();
                }
                listado=(ListView) findViewById(R.id.listado);
                ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this,
                        android.R.layout.simple_list_item_1, titulos);
                listado.setAdapter(adapter);

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }
}