Android Error Parsing string to json

Question

Need help on android =( been stuck on this for ages! My codes are as shown.

public class AllUsersActivity extends ListActivity {

// Progress Dialog
private ProgressDialog pDialog;

// Creating JSON Parser object
JSONParser jParser = new JSONParser();

ArrayList<HashMap<String, String>> usersList;

// url to get all users list
private static String url_all_users = "http://10.0.2.2/android_connect/get_all_users.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_USERS = "users";
private static final String TAG_UID = "UserID";
private static final String TAG_FIRSTNAME = "FirstName";

// users JSONArray
JSONArray users = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.all_users);

    // Hashmap for ListView
    usersList = new ArrayList<HashMap<String, String>>();

    // Loading users in Background Thread
    new LoadAllusers().execute();

    // Get listview
    ListView lv = getListView();

    // on seleting single product
    // launching Edit Product Screen
    lv.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // getting values from selected ListItem
            String uid = ((TextView) view.findViewById(R.id.uid)).getText()
                    .toString();

            // Starting new intent
            Intent in = new Intent(getApplicationContext(),
                    UserDetailsActivity.class);
            // sending uid to next activity
            in.putExtra(TAG_UID, uid);

            // starting new activity and expecting some response back
            startActivityForResult(in, 100);
        }
    });

}

// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // if result code 100
    if (resultCode == 100) {
        // if result code 100 is received
        // means user edited/deleted product
        // reload this screen again
        Intent intent = getIntent();
        finish();
        startActivity(intent);
    }

}

/**
 * Background Async Task to Load all product by making HTTP Request
 * */
class LoadAllusers extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AllUsersActivity.this);
        pDialog.setMessage("Loading users. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All users from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_all_users, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("All users: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // users found
                // Getting Array of users
                users = json.getJSONArray(TAG_USERS);

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

                    // Storing each json item in variable
                    String id = c.getString(TAG_UID);
                    String name = c.getString(TAG_FIRSTNAME);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_UID, id);
                    map.put(TAG_FIRSTNAME, name);

                    // adding HashList to ArrayList
                    usersList.add(map);
                }
            } 
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after getting all users
        pDialog.dismiss();
        // updating UI from Background Thread
        runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */
                ListAdapter adapter = new SimpleAdapter(
                        AllUsersActivity.this, usersList,
                        R.layout.list_item, new String[] { TAG_UID,
                                TAG_FIRSTNAME},
                        new int[] { R.id.uid, R.id.name });
                // updating listview
                setListAdapter(adapter);
            }
        });

    }

}

Can anyone please help me! The error i've been getting is Error Parsing Data Org.json.JSONException: Value cannot be converted to JSONObject

Heres the JSON string

Array{"Users":[{"UserID":"1","FirstName":"lalawee","Email":"12345","Password":null},{"UserID":"2","FirstName":"shadowblade721","Email":"12345","Password":null},{"UserID":"3","FirstName":"dingdang","Email":"12345","Password":null},{"UserID":"4","FirstName":"solidsnake0328","Email":"12345","Password":null}],"success":1}

Is the error lying in the JSON parser class?

EDIT: here the code for the php script that outputs the array above. can anyone tell me what's wrong with the php script that outputs the word array before the json string? Sorry for the trouble. I'm new to coding. Been following online tutorials but stuck on this for a few days now.

<?php
/*
* Following code will list all the Users
*/
// array for JSON response
$response = array();
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// get all Users from Users table
$result = mysql_query("SELECT * FROM Users") or die(mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// looping through all results
// Users node
$response["Users"] = array();

while ($row = mysql_fetch_array($result)) {
    // temp user array
    $user[] = array();
    $user["UserID"] = $row["UserID"];
    $user["FirstName"] = $row["FirstName"];
    $user["Email"] = $row["Email"];
    $user["Password"] = $row["Password"];

    // push single User into final response array
    array_push($response["Users"], $user);
}
// success
$response["success"] = 1;
echo $response;

// echoing JSON response
echo json_encode($response);
}
else {
// no Users found
$response["success"] = 0;
$response["message"] = "No Users found";

// echo no users JSON
echo json_encode($response);
}
?>

Answer 1

Use GSON library instead, it is official Google and works like a charm. No HashMaps etc, immediate objects.

Take a look at it here.

Answer 2

As the error suggests, your JSON string does not represent a valid JSON object.

Try like this(without Array in the beginning):

{"Users":[{"UserID":"1","FirstName":"lalawee","Email":"12345","Password":null},{"UserID":"2","FirstName":"shadowblade721","Email":"12345","Password":null},{"UserID":"3","FirstName":"dingdang","Email":"12345","Password":null},{"UserID":"4","FirstName":"solidsnake0328","Email":"12345","Password":null}],"success":1}Array{"Users":[{"UserID":"1","FirstName":"lalawee","Email":"12345","Password":null},{"UserID":"2","FirstName":"shadowblade721","Email":"12345","Password":null},{"UserID":"3","FirstName":"dingdang","Email":"12345","Password":null},{"UserID":"4","FirstName":"solidsnake0328","Email":"12345","Password":null}],"success":1}

You can check the validity of your JSON String here: http://jsonlint.com/