Android: Error parsing data and cannot be converted to JSONObject

Question

I'm trying to send the user_id to PHP through JSON but it shows Error parsing data org.json.JSONException: Value 2 of type java.lang.Integer cannot be converted to JSONObject.

How can i make this work? Thank you in advance.

Class :

public class Home1 extends Activity {

JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapter1 adapterrr;

SharedPreferences pref;
String uid;
String user_i,us;
String ques_i;
ArrayList<HashMap<String, String>> arraylist;

//static String BET_ID = "bet_id";
static String QUESTION = "question";
static String QUES_ID = "ques_id";
static String ANSWER = "answer";

ArrayList<HashMap<String, String>> data;



HashMap<String, String> resultp = new HashMap<String, String>();
Set<String> newset=new HashSet<String>();

@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    pref = PreferenceManager.getDefaultSharedPreferences(this);
    setContentView(R.layout.questionlist1);

uid = pref.getString("user_id",null);
Log.d("uid", ""+uid);

Intent i = getIntent();
ques_i = i.getStringExtra("qsid");
Log.d("qsid", ""+ques_i);


new DownloadJSON().execute();
}


private class DownloadJSON extends AsyncTask<Void, Void, Void> {

    /*protected ArrayList<NameValuePair> parameters;


    public DownloadJSON() {

    parameters = new ArrayList<NameValuePair>();

    NameValuePair us = new BasicNameValuePair("user_id", uid);
    parameters.add(us);
    }*/


    @Override
    protected Void doInBackground(Void... params) {


        arraylist = new ArrayList<HashMap<String, String>>();

        /*jsonobject = JSONfunctions
                .getJSONfromURL("http://192.168.1.23/mutilatedphp/QuizGame/filtercheck.php");*/

        try {

            jsonobject = JSONfunctions
                    .getJSONfromURL("http://192.168.1.23/mutilatedphp/QuizGame/filtercheck.php?user_id="+uid);
            jsonarray = jsonobject.getJSONArray("ques");

            for (int i = 0; i < jsonarray.length(); i++) {
                HashMap<String, String> map = new HashMap<String, String>();
                jsonobject = jsonarray.getJSONObject(i);

                map.put("ques_id", jsonobject.getString("ques_id"));
                map.put("question", jsonobject.getString("question"));  
                map.put("answer", jsonobject.getString("answer"));


                arraylist.add(map);
            }
        } catch (JSONException e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void args) {

        listview = (ListView) findViewById(R.id.listView2);

        adapterrr = new ListViewAdapter1(Home1.this, arraylist);

        listview.setAdapter(adapterrr);


    }

Answer 1

I think the problem is that you haven't check whether the attribute 'ques' exists. When you use getJSONArray() method on an non-exist attribute, JSON library will throw a exception and crash your app.

You can take a look at my little example, it checks the existence of 'ques' before doing anything further:

import org.json.JSONArray;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

public class SimpleTest {
    public static void main(String[] args) {
        String notOk = "{\n" +
                "\t\"success\":0,\n" +
                "\t\"message\":\"No Categories found\"\n" +
                "}";

        String ok = "{\n" +
                "\t\"ques\":\n" +
                "\t\t[\n" +
                "\t\t\t{\n" +
                "\t\t\t\t\"ques_id\":\"3\",\n" +
                "\t\t\t\t\"question\":\"What is the currency of Japan?\",\n" +
                "\t\t\t\t\"answer\":\"Yen\"\n" +
                "\t\t\t}\n" +
                "\t\t],\n" +
                "\t\"success\":1,\n" +
                "\t\"message\":\"Successfully found \"\n" +
                "}";

        JSONObject okJSON = new JSONObject(ok);
        JSONObject notOkJSON = new JSONObject(notOk);

        System.out.println(new SimpleTest().parseJson(okJSON));
        System.out.println(new SimpleTest().parseJson(notOkJSON));
    }

    public Map<String, String> parseJson(JSONObject jsonObject) {
        if (jsonObject.has("ques")) {
            JSONArray jsonArray = jsonObject.getJSONArray("ques");
            Map<String, String> map = new HashMap<String, String>();
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject tempObject = jsonArray.getJSONObject(i);

                map.put("ques_id", tempObject.getString("ques_id"));
                map.put("question", tempObject.getString("question"));
                map.put("answer", tempObject.getString("answer"));
            }

            return map;
        } else {
            return new HashMap<String, String>();
        }
    }
}

Or, it is totally ok to use the 'success' attribute to check the result and tell you whether 'ques' attribute exists. Hope my answer can give you a little help.

Answer 2

The problem is caused by this line

jsonobject = jsonarray.getJSONObject(i);

You are trying to convert an object of type Integer into a JSONObject. The problem is on the server side. Please post your response, if you found the problem, so I can verify if I'm right here.