Java — не удается получить JSON для счетчика

Привет, вы, ребята, можете помочь мне, потому что я застрял здесь как всегда, и каждый раз, когда я получаю свой JSON от моего веб-хоста, он всегда нулевой на моем веб-хосте, и когда я проверяю строку, Log.d эта ошибка показывает NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.toString()' on a null object

Вот мои коды.

<?PHP
include_once("connection.php");

session_start();

$where = '';
if (isset($_GET['driverOwner']) && isset($_GET['roles']) && isset ($_GET['driverStatus'])){
$where = " WHERE driverOwner = '".addslashes($_GET['driverOwner'])."' AND roles = '".addslashes($_GET['roles'])."'  AND driverStatus = '".addslashes($_GET['driverSTatus'])."'";
}

$query = "SELECT * FROM tbl_user ".$where."";

$result = mysqli_query($conn, $query);

if($result)

{
while ($row = mysqli_fetch_assoc($result)) {

$data[] = $row;

}

echo json_encode($data);
}

mysqli_close($conn);

?>

public class Drivers1 {
int id;
String name;

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

}

public class Connector {

public static HttpURLConnection connect(String urlAddress){

try{
URL url = new URL(urlAddress);
HttpURLConnection con = (HttpURLConnection) url.openConnection();

//SET PROPERTIES
con.setRequestMethod("GET");
con.setConnectTimeout(20000);
con.setReadTimeout(20000);
con.setDoInput(true);
return con;

} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}

public class DataParser extends AsyncTask<Void,Void,Integer> {

Context c;
Spinner spDriver;
String  jsonData;ProgressDialog pd;
ArrayList<String> driver = new ArrayList<>();public DataParser(Context c, Spinner sp, String jsonData) {
this.c = c;
this.spDriver = sp;
this.jsonData = jsonData;
}@Override
protected void onPreExecute() {
super.onPreExecute();

pd = new ProgressDialog(c);
pd.setTitle("Fetch");
pd.setMessage("Please wait... Getting drivers");
pd.show();
}

@Override
protected Integer doInBackground(Void... voids) {
return this.parseData();
}

@Override
protected void onPostExecute(Integer result) {
super.onPostExecute(result);

pd.dismiss();

if(result == 0 ){
Toast.makeText(c, "Failed", Toast.LENGTH_SHORT).show();
}else {//BIND
ArrayAdapter adapter = new ArrayAdapter(c,android.R.layout.simple_list_item_1, driver);
spDriver.setAdapter(adapter);

spDriver.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
Toast.makeText(c, driver.get(i), Toast.LENGTH_SHORT).show();
}

@Override
public void onNothingSelected(AdapterView<?> adapterView) {

}
});
}
}

private int parseData(){

try {
JSONArray ja = new JSONArray(jsonData);
JSONObject jo = null;

driver.clear();
Drivers1 s=null;

for (int i=0;i<ja.length();i++){
jo=ja.getJSONObject(i);

int id=jo.getInt("userID");
String name=jo.getString("firstname");

s = new Drivers1();
s.setId(id);
s.setName(name);

driver.add(name);

}
return 1;
} catch (JSONException e) {
e.printStackTrace();
}
return 0;
}
}

public class Downloader extends AsyncTask<Void,Void,String> {

Context c;
String urlAddress;
Spinner spDriver;

ProgressDialog pd;

public Downloader(Context c, String urlAddress, Spinner spDriver) {
this.c = c;
this.urlAddress = urlAddress;
this.spDriver = spDriver;
}

@Override
protected void onPreExecute() {
super.onPreExecute();

pd = new ProgressDialog(c);
pd.setTitle("Fetch(Downloader)");
pd.setMessage("Please wait... Getting Drivers");
pd.show();
}

@Override
protected String doInBackground(Void... voids) {
return this.downloadData();
}@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
Log.d("Downloader",""+ s);

pd.dismiss();

if (s == null) {
Toast.makeText(c, "Unable to retrieve", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(c, "Success!", Toast.LENGTH_SHORT).show();

//CALL PARSER CLASS TO PARSE
DataParser parser = new DataParser(c,spDriver,s);
parser.execute();
}
}

private String downloadData(){

HttpURLConnection con = Connector.connect(urlAddress);
if(con == null){
return null;
}

InputStream is=null;
try {
is = new BufferedInputStream(con.getInputStream());
BufferedReader br = new BufferedReader(new InputStreamReader(is));

String line = "";
StringBuffer response = new StringBuffer();

if (br != null) {
while ((line = br.readLine()) != null){
response.append(line+"\n");
}
}else {
return null;
}} catch (IOException e) {
e.printStackTrace();
}finally {
if(is != null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

return null;
}
}

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_insert);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

Spinner spDriver = (Spinner) findViewById(R.id.spDriver);

String url = "http://carkila.esy.es/carkila/getDriver.php?driverOwner="+ pref.getString("username","")+"&roles=driver&driverStatus=active";

new Downloader(InsertActivity.this,url ,spDriver).execute();
}

Извините за длинный пост, но, пожалуйста, помогите мне. : c thaaaaanks 🙂

Ошибка при Log.d("Downlaoder",s.toString()); проверено на Downloader.java.

Process: com.example.kun.carkila, PID: 31098
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.toString()' on a null object reference
at com.example.kun.carkila.mMySQL.Downloader.onPostExecute(Downloader.java:56)
at com.example.kun.carkila.mMySQL.Downloader.onPostExecute(Downloader.java:24)
at android.os.AsyncTask.finish(AsyncTask.java:632)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5289)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)