Apps JSON Parsing Error Value on showing string(ArrayList) to a ListView

[Criinx]

I'm getting this error on parsing my JSON data into a list view.

Error Parsing Value:

my code

@Override
        protected Void doInBackground(Void... params) {
            HttpHandler sh = new HttpHandler();
            String url = "my link";
            String jsonStr = sh.makeServiceCall(url);

        Log.e(TAG, "Response from URL:" + jsonStr);
        if (jsonStr != null){
            try {
                JSONObject jsonObject = new JSONObject(jsonStr);

I have my Arraylist which is going to a list_item view.

I don't know why it's not showing up.

JSONArray mandant = jsonObject.getJSONArray("get_schedule_data_employee");

                for (int i = 0; i < mandant.length(); i++){
                    JSONObject m = mandant.getJSONObject(i);

                    String name = m.getString("firstname");
                    String schift = m.getString("schift");

                    JSONObject phone = m.getJSONObject("schift");
                    String remark = phone.getString("remark");
                    String home = phone.getString("mandator");
                    String office = phone.getString("mandator");

                    HashMap <String, String> mandants = new HashMap<>();

                    mandants.put("schift", schift);
                    mandants.put("firstname", name);
                    mandants.put("remark", remark);
                    mandants.put("mandator", home);
                    mandants.put("mandtaor", office);

                    mandantList.add(mandants);
                }
            }

I'm coming to this line after that it's nothing showing anymore

catch (final JSONException e){
                Log.e(TAG, "Json 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, "JSON Verbindung mit Server nicht möglich");
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getApplicationContext(),"JSON Verbindung mit Server konnte nicht hergestellt werden, versuchen Sie es über LOGCAT", Toast.LENGTH_LONG).show();
                }
            });
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        ListAdapter adapter = new SimpleAdapter(MainActivity.this, mandantList, R.layout.list_item, new String[]{"firstname","schift"}, new int[]{R.id.name, R.id.schift});
        lv.setAdapter(adapter);
    }
}}

Error Log:

03-17 14:52:45.707 28585-28663/com.example.cicajos.testlist E/MainActivity: Response from URL:

03-17 14:52:45.733 28585-28663/com.example.cicajos.testlist E/MainActivity: Json ERRORValue [{"mandator_id":"1","mandator":"WG ","department_id":"22","department":"WG ","employee_id":"1111","firstname":"Firstname","surname":"Surname","shortname":"","