java.lang.string无法转换为JSONArray Android Mysql

Question

我正在尝试推送Book On Not的通知今天为我的库移动应用程序，但在我登录后，我的应用程序中弹出此错误。

4：运行java.lang.string无法转换为JSONArray。

我的php工作正常，但我该如何解决这个错误？

W/System.err: org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONArray
W/System.err:     at org.json.JSON.typeMismatch(JSON.java:111)
W/System.err:     at org.json.JSONArray.<init>(JSONArray.java:96)
W/System.err:     at org.json.JSONArray.<init>(JSONArray.java:108)
W/System.err:     at com.example.ivan.librarymobileapp.backWorkerNotif.doInBackground(backWorkerNotif.java:67)
W/System.err:     at com.example.ivan.librarymobileapp.backWorkerNotif.doInBackground(backWorkerNotif.java:23)
W/System.err:     at android.os.AsyncTask$2.call(AsyncTask.java:288)
W/System.err:     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
W/System.err:     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
W/System.err:     at java.lang.Thread.run(Thread.java:818)

这是我的代码：

backWorkerNotif类

public class backWorkerNotif extends AsyncTask<String, String, String> {
   String result = null;
   String[] BookTittle;
   Context context;
   public  backWorkerNotif(Context context){this.context = context;}

   @Override
   protected String doInBackground(String... params) {
      String selectNotif_url = "http://192.168.254.120/LibrayAPI/SelectNotif.php";
      String type = params[0];

      if (type.equals("Notif")) {
        String DateNow = params[1];
        String BorrowerID = params[2];
        try {

          String data = URLEncoder.encode("date_now", "UTF-8") + "=" +
                        URLEncoder.encode(DateNow, "UTF-8");
                data += "$" + URLEncoder.encode("borrower_id", "UTF-8") + "=" +
                        URLEncoder.encode(BorrowerID, "UTF-8");

               URL url = new URL(selectNotif_url);
               URLConnection urlConnection = url.openConnection();
               urlConnection.setDoOutput(true);

               OutputStreamWriter outputStreamWriter = new OutputStreamWriter(urlConnection.getOutputStream());

               outputStreamWriter.write(data);
               outputStreamWriter.flush();

               BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
               StringBuilder sb = new StringBuilder();
               String line;
               while ((line = bufferedReader.readLine()) != null) {

                 sb.append(line + "
");
               }
               result = sb.toString();
            } catch (Exception ex) {


            }
            //Json
            try {
                JSONArray jsonArray = new JSONArray(result);
                JSONObject jsonObject;
                BookTittle = new String[jsonArray.length()];
                for (int i = 0;i< jsonArray.length();i++){
                    jsonObject = jsonArray.getJSONObject(i);
                    BookTittle[i] = jsonObject.getString("BookTittle");

                    NotificationCompat.Builder  mbuilder = new NotificationCompat.Builder(context)
                            .setSmallIcon(R.drawable.ic_book_black_24dp)
                            .setContentTitle("Library notification")
                            .setContentText("Today is the Due Day of"+ BookTittle[i] +"You Borrowed");
                    NotificationManager notificationManager =(NotificationManager)context.getSystemService(context.NOTIFICATION_SERVICE);
                    notificationManager.notify(0,mbuilder.build())
                }   
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
        return null;
    }

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

    @Override
    protected void onPostExecute(String jsonArray) {
        super.onPostExecute(jsonArray);
    }
}

登录类

public class Login extends AppCompatActivity {

    EditText username,password;

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

        username = findViewById(R.id.edtUsername);
        password = findViewById(R.id.edtPassword);
    }

    public void onLogin(View view) {

        String Username = username.getText().toString();
        String Password = password.getText().toString();
        backWorkerNotif backWorkerNotif = new backWorkerNotif(this);
        Date date = Calendar.getInstance().getTime();
        SimpleDateFormat SF = new SimpleDateFormat("yyyy-MM-dd");
        String DateNow = SF.format(date);
        backWorkerNotif.execute("Notif", DateNow, Username);

        String Type = "login";
        GlobalVariable.BorrowerID = Username;
        backgroundWorker _backgroundWorker = new backgroundWorker(this);
        _backgroundWorker.execute(Type, Username, Password);
    }
}

我的PHP代码

<?php
require "Connection.php";
$DateNow = $_POST["date_now"];
$BorrowerID = $_POST["borrower_id"];

$query = "SELECT A.`BookId`,B.`BookTittle`,A.`BorrowerId` FROM `tblborrow` AS A INNER JOIN `tblbooks` AS B ON A.`BookId` = B.`BookId` WHERE `DueDate` = '$DateNow' AND `BorrowerId` = '$BorrowerID'";
$result = mysqli_query($conn,$query);

while($e = mysqli_fetch_assoc($result)){
    $output[] = $e;
}
echo json_encode($output);
print (json_encode($output));
?>

我的PHP的结果

[
  {"BookId":"101","BookTittle":"Counting dolars","BorrowerId":"11"},
  {"BookId":"9876","BookTittle":"ihi","BorrowerId":"11"},
  {"BookId":"542","BookTittle":"hiragana","BorrowerId":"11"},
  {"BookId":"5421","BookTittle":"wow","BorrowerId":"11"}
][
  {"BookId":"101","BookTittle":"Counting dolars","BorrowerId":"11"},
  {"BookId":"9876","BookTittle":"ihi","BorrowerId":"11"},  
  {"BookId":"542","BookTittle":"hiragana","BorrowerId":"11"},  
  {"BookId":"5421","BookTittle":"wow","BorrowerId":"11"}
]

我做错了什么？