Get JSON object from HTTP response

Question

I want to get a JSON object from an Http get response:

Here is my current code for Http get:

 protected String doInBackground(String... params) { HttpClient client = new DefaultHttpClient(); HttpGet request = new HttpGet(params[0]); HttpResponse response; String result = null; try { response = client.execute(request); HttpEntity entity = response.getEntity(); if (entity != null) { // A Simple JSON Response Read InputStream instream = entity.getContent(); result = convertStreamToString(instream); // now you have the string representation of the HTML request System.out.println("RESPONSE: " + result); instream.close(); if (response.getStatusLine().getStatusCode() == 200) { netState.setLogginDone(true); } } // Headers org.apache.http.Header[] headers = response.getAllHeaders(); for (int i = 0; i < headers.length; i++) { System.out.println(headers[i]); } } catch (ClientProtocolException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } return result; } 

Here is the convertSteamToString function:

 private static String convertStreamToString(InputStream is) { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); } 

Now I just get the string object. How can I return a JSON object.

Answer 1

The string you get is just a JSON Object.toString () object. This means that you get a JSON object, but in String format.

If you should get a JSON Object, you can simply put:

 JSONObject myObject = new JSONObject(result); 

Answer 2

Do it to get JSON

 String json = EntityUtils.toString(response.getEntity()); 

Read more here: get json from HttpResponse

Answer 3

Despite your exact JSON output, it's hard to give you some sort of working code. This tutorial is very useful, but you can use something according to:

 JSONObject jsonObj = new JSONObject("yourJsonString"); 

Then you can extract json from this object using:

 String value = jsonObj.getString("yourKey"); 

Answer 4

This is not an exact answer to your question, but it may help you.

 public class JsonParser { private static DefaultHttpClient httpClient = ConnectionManager.getClient(); public static List<Club> getNearestClubs(double lat, double lon) { // YOUR URL GOES HERE String getUrl = Constants.BASE_URL + String.format("getClosestClubs?lat=%f&lon=%f", lat, lon); List<Club> ret = new ArrayList<Club>(); HttpResponse response = null; HttpGet getMethod = new HttpGet(getUrl); try { response = httpClient.execute(getMethod); // CONVERT RESPONSE TO STRING String result = EntityUtils.toString(response.getEntity()); // CONVERT RESPONSE STRING TO JSON ARRAY JSONArray ja = new JSONArray(result); // ITERATE THROUGH AND RETRIEVE CLUB FIELDS int n = ja.length(); for (int i = 0; i < n; i++) { // GET INDIVIDUAL JSON OBJECT FROM JSON ARRAY JSONObject jo = ja.getJSONObject(i); // RETRIEVE EACH JSON OBJECT FIELDS long id = jo.getLong("id"); String name = jo.getString("name"); String address = jo.getString("address"); String country = jo.getString("country"); String zip = jo.getString("zip"); double clat = jo.getDouble("lat"); double clon = jo.getDouble("lon"); String url = jo.getString("url"); String number = jo.getString("number"); // CONVERT DATA FIELDS TO CLUB OBJECT Club c = new Club(id, name, address, country, zip, clat, clon, url, number); ret.add(c); } } catch (Exception e) { e.printStackTrace(); } // RETURN LIST OF CLUBS return ret; } } Again, it's relatively straight forward, but the methods I'll make special note of are: JSONArray ja = new JSONArray(result); JSONObject jo = ja.getJSONObject(i); long id = jo.getLong("id"); String name = jo.getString("name"); double clat = jo.getDouble("lat"); 

Answer 5

You need to use JSONObject as shown below:

 String mJsonString = downloadFileFromInternet(urls[0]); JSONObject jObject = null; try { jObject = new JSONObject(mJsonString); } catch (JSONException e) { e.printStackTrace(); return false; } 

...

 private String downloadFileFromInternet(String url) { if(url == null /*|| url.isEmpty() == true*/) new IllegalArgumentException("url is empty/null"); StringBuilder sb = new StringBuilder(); InputStream inStream = null; try { url = urlEncode(url); URL link = new URL(url); inStream = link.openStream(); int i; int total = 0; byte[] buffer = new byte[8 * 1024]; while((i=inStream.read(buffer)) != -1) { if(total >= (1024 * 1024)) { return ""; } total += i; sb.append(new String(buffer,0,i)); } } catch(Exception e ) { e.printStackTrace(); return null; }catch(OutOfMemoryError e) { e.printStackTrace(); return null; } return sb.toString(); } private String urlEncode(String url) { if(url == null /*|| url.isEmpty() == true*/) return null; url = url.replace("[",""); url = url.replace("]",""); url = url.replaceAll(" ","%20"); return url; } 

Hope this helps you.

Answer 6

There is a JSONObject constructor that turns a String into a JSONObject:

http://developer.android.com/reference/org/json/JSONObject.html#JSONObject(java.lang.String)