goo.gl URL shortener for Android

gistfile1.txt

import android.os.AsyncTask;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

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

/**
 * Created by piero on 2/17/15.
 * Usage
 * new URLShortener().getShortUrl(url, new URLShortener.RequestEndListner() {
 *           @Override
 *           public void onRequestEnd(String shortUrl) {
 *             //use shortUrl for your purpose
 *           }
 *
 *          @Override
 *           public void onRequestException() {
 *              //something went wrong
 *           }
 *       });
 */
public class URLShortener {
    final String address = "https://www.googleapis.com/urlshortener/v1/url";

    public void getShortUrl(String longUrl, RequestEndListner requestEndListner) {
        new UrlShortnerRequest().execute(longUrl, requestEndListner);
    }

    public interface RequestEndListner {
        public void onRequestEnd(String url);

        public void onRequestException();
    }

    private class UrlShortnerRequest extends AsyncTask<Object, Void, JSONObject> {
        RequestEndListner listeRequestEndListner;

        @Override
        protected JSONObject doInBackground(Object... params) {
            try {
                listeRequestEndListner = (RequestEndListner) params[1];
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(address);
                JSONObject json = new JSONObject();
                json.put("longUrl", params[0]);
                httpPost.setEntity(new StringEntity(json.toString()));
                httpPost.setHeader("Content-Type", "application/json");
                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                return jsonStream2Object(httpEntity.getContent());
            } catch (Exception e) {
            }
            return null;
        }

        protected void onPostExecute(JSONObject result) {
            if (result == null) {
                listeRequestEndListner.onRequestException();
            } else {
                try {
                    listeRequestEndListner.onRequestEnd(result.getString("id"));
                } catch (JSONException e) {
                    listeRequestEndListner.onRequestException();
                    e.printStackTrace();
                }
            }
        }

        private String stream2String(InputStream inputStream) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream), 8);
            StringBuilder sb = new StringBuilder();
            String line;
            try {
                while ((line = reader.readLine()) != null) {
                    sb.append(line);
                }
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return sb.toString();
        }

        private JSONObject jsonStream2Object(InputStream inputStream) throws JSONException {
            return new JSONObject(stream2String(inputStream));
        }

    }
}