Retrieving a JSON array from an Android application

Question

I manage to retrieve Json content from the URL: http://twitter.com/statuses/public_timeline.json Which provide just tweets. Now I want to retrieve another JSON array from another URL, which has the follwoing format:

  {
"contacts": [
    {
            "id": "c200",
            "name": "Ravi Tamada",
            "email": "[email protected]",
            "address": "xx-xx-xxxx,x - street, x - country",
            "gender" : "male",
    },
    {
            "id": "c201",
            "name": "Johnny Depp",
            "email": "[email protected]",
            "address": "xx-xx-xxxx,x - street, x - country",
            "gender" : "male",

    },
    .
    .
}

The diference as you can verify is that the one JSON array has a name and the second not. The code that I was used for the tweet retrieving, was the following one:

  private class LoadListTask extends AsyncTask<Void, Tweet, Void> {

    private final ProgressDialog pd = new ProgressDialog(TweetTestActivity.this);

      // can use UI thread here
      @SuppressWarnings("unchecked")
    protected void onPreExecute() {
          ((ArrayAdapter<String>)getListAdapter()).clear();
         this.pd.setMessage("Loading List...");
         this.pd.show();
      }

    protected Void doInBackground(Void... ars) {
         // TODO    4 new activity with custom adapter to show schedules
         try {
            HttpClient client = new DefaultHttpClient();
            HttpGet get = new HttpGet("http://twitter.com/statuses/public_timeline.json");

            ResponseHandler<String> responseHandler = new BasicResponseHandler();

            JSONArray ja = new JSONArray(client.execute(get, responseHandler));

            for (int i = 0; i < ja.length(); i++) {
                 JSONObject jo = (JSONObject) ja.get(i);
                 publishProgress(new Tweet(jo.getString("id_str"),jo.getString("text")));
            }
         } catch (IOException e) {
             e.printStackTrace();
         } catch (JSONException e) {
             e.printStackTrace();
         } catch (Exception e) {
             e.printStackTrace();
        }

         return null;
     }

     @SuppressWarnings("unchecked")
    protected void onProgressUpdate(Tweet... progress) {
         ((ArrayAdapter<Tweet>)getListAdapter()).add(progress[0]);
         }

     protected void onPostExecute(Void result) {
         pd.dismiss();
     }
 }

Question: What changes should i perform to retrieve the contacts array? Because when i just change the id_str to gender(and the URL of course) i take an error which says: org.json.JSONException: No value for gender.

MAC · Accepted Answer · 2012-10-06 15:03:21Z

1

JSONObject jObj = new JSONObject (client.execute(get, responseHandler));

JSONArray ja = new JSONArray(jObj.getJSONArray("contacts"));
enter code here
for (int i = 0; i < ja.length(); i++) {
    JSONObject jo = (JSONObject) ja.get(i);
    publishProgress(new Tweet(jo.getString("id_str"),jo.getString("text")));
}

And there is no String like text and you are reading ---> jo.getString("text"); why ?

answered Oct 6, 2012 at 15:03

MAC

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2 Comments

Nick Robertson Over a year ago

Thank you MAC for your answer. The jo.getString("text"); was used in order to retrieve only the text attribute of the JSON object

Nick Robertson Over a year ago

MAC i did the changes you proposed but in the JSONArray line it hit's me an error. It says:'The constructor JSONArray(JSONArray) is undefined'. The solutuion that is propose by the IDE is to cast argument1 to Collection. I did this change, but it doesn't print the results.

logcat · Accepted Answer · 2012-10-06 17:26:35Z

0

That's awesome to use json api. But consider object mapper's like gson http://code.google.com/p/google-gson/ or jackson http://jackson.codehaus.org/ . They may keep your code concise.

answered Oct 6, 2012 at 17:26

logcat

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