Android JSON Parsing - End of input at character 0 of error

Question

This is my first time making an android application that parses JSON data. However, I'm encountering an error regarding JSON parsing. I've tried Googling the problem but most of the solutions didn't work for me.

Here are my codes:

MainActivity.java

package com.example.jsonparser;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;

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

import java.util.ArrayList;
import java.util.HashMap;

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();

    private ProgressDialog pDialog;
    private ListView lv;

    // URL to get contacts JSON
    private static String url = "http://pastebin.com/raw/79D93HR4";

    ArrayList<HashMap<String, String>> itemList;

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

        itemList = new ArrayList<>();

        lv = (ListView) findViewById(R.id.list);

        new GetItems().execute();
    }

    /**
     * Async task class to get json by making HTTP call
     */
    private class GetItems extends AsyncTask<Void, Void, Void> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // Showing progress dialog
            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Please wait...");
            pDialog.setCancelable(false);
            pDialog.show();

        }

        @Override
        protected Void doInBackground(Void... arg0) {
            HttpHandler sh = new HttpHandler();

            // Making a request to url and getting response
            String jsonStr = sh.makeServiceCall(url);

            Log.e(TAG, "Response from url: " + jsonStr);

            if (jsonStr != null) {
                try {
                    //JSONObject jsonObj = new JSONObject(jsonStr);

                    // Getting JSON Array node
                    JSONArray items = new JSONArray("");

                    // looping through All Contacts
                    for (int i = 0; i < items.length(); i++) {
                        JSONObject c = items.getJSONObject(i);

                        String ItemCode = c.getString("ItemCode");
                        String ItemName = c.getString("ItemName");

                        // tmp hash map for single item
                        HashMap<String, String> item = new HashMap<>();

                        // adding each child node to HashMap key => value
                        item.put("ItemCode", ItemCode);
                        item.put("ItemName", ItemName);

                        // adding item to item list
                        itemList.add(item);
                    }

                } catch (final JSONException e) {
                    Log.e(TAG, "Json parsing error: " + e.getMessage());
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            Toast.makeText(getApplicationContext(),
                                    "Json parsing error: " + e.getMessage(),
                                    Toast.LENGTH_LONG)
                                    .show();
                        }
                    });

                }
            } else {
                Log.e(TAG, "Couldn't get json from server.");
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(getApplicationContext(),
                                "Couldn't get json from server. Check LogCat for possible errors!",
                                Toast.LENGTH_LONG)
                                .show();
                    }
                });

            }

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            // Dismiss the progress dialog
            if (pDialog.isShowing())
                pDialog.dismiss();
            /**
             * Updating parsed JSON data into ListView
             * */
            ListAdapter adapter = new SimpleAdapter(
                    MainActivity.this, itemList,
                    R.layout.list_item, new String[]{"ItemCode", "ItemName"}, new int[]{R.id.ItemCode,
                    R.id.ItemName});

            lv.setAdapter(adapter);
        }

    }
}

HttpHandler.java

package com.example.jsonparser;

/**
 * Created by Me on 1/3/2017.
 */
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;

public class HttpHandler {

    private static final String TAG = HttpHandler.class.getSimpleName();

    public HttpHandler() {
    }

    public String makeServiceCall(String reqUrl) {
        String response = null;
        try {
            URL url = new URL(reqUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            // read the response
            InputStream in = new BufferedInputStream(conn.getInputStream());
            response = convertStreamToString(in);
        } catch (MalformedURLException e) {
            Log.e(TAG, "MalformedURLException: " + e.getMessage());
        } catch (ProtocolException e) {
            Log.e(TAG, "ProtocolException: " + e.getMessage());
        } catch (IOException e) {
            Log.e(TAG, "IOException: " + e.getMessage());
        } catch (Exception e) {
            Log.e(TAG, "Exception: " + e.getMessage());
        }
        return response;
    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line).append('\n');
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}

And here is the error code:

01-04 00:13:05.366 10069-10112/com.example.jsonparser E/MainActivity: Response from url: [{"ItemCode":"C0100001  ","ItemName":"UBNT CRM-P-CRM Point","LocationCode":null,"ViewBy":null,"SearchDate":null,"CutOffDate":"\/Date(-62135596800000)\/","CurrentDate":"\/Date(-62135596800000)\/"},{"ItemCode":"C0100002  ","ItemName":"UBNT ETH-SP-Ethernet Surge Protector","LocationCode":null,"ViewBy":null,"SearchDate":null,"CutOffDate":"\/Date(-62135596800000)\/","CurrentDate":"\/Date(-62135596800000)\/"}]
01-04 00:13:05.367 10069-10112/com.example.jsonparser E/MainActivity: Json parsing error: End of input at character 0 of 

What am I doing wrong?

Answer 1

JSONArray need a json string. Pass your json in JSONArray initialize

JSONArray items = new JSONArray(jsonStr );

Answer 2

                JSONArray items = new JSONArray("");

You're passing in an empty string to convert from json. Since there's no data in the string, its failing at character 0 with invalid input (the input isn't valid JSON).