JavaFX bekerja dengan elemen TextField dan TableView.

Tolong bantu saya mencari tahu. Ada beberapa kelas. Kelas Karyawan adalah objek yang dapat berisi data bertipe SimpleStringProperty. Ada file fxml yang berisi tata letak jendela untuk menambah/mengubah daftar objek Karyawan. Kelas AddEmployee adalah pengendali kejadian untuk file fxml. Saat menambahkan teks ke TextField dari objek yang dipilih, Karyawan mulai mengumpat. Jika dilihat secara terpisah, data “diekstraksi” dari objek, tetapi tidak dapat dimasukkan ke dalam TextField. Kode pengendali: @FXML private TextField tf_employee; @FXML private TextField tf_surname; @FXML private TextField tf_name; @FXML private TextField tf_patronymic; @FXML private TextField tf_post; Employees employees; public void setEmployees(Employees employees) { if (employees == null){ return; } this.employees = employees; tf_employee.setText(employees.getId_eml()); tf_employee.setText(employees.getId_eml().toString()); tf_surname.setText(employees.getSurname_empl()); tf_name.setText(employees.getName_empl().toString()); tf_patronymic.setText(employees.getPathronymic_empl()); tf_post.setText(employees.getPost_empl()); } Kode objek: private SimpleStringProperty id_eml = new SimpleStringProperty(""); private SimpleStringProperty surname_empl = new SimpleStringProperty(""); private SimpleStringProperty name_empl = new SimpleStringProperty(""); private SimpleStringProperty pathronymic_empl = new SimpleStringProperty(""); private SimpleStringProperty post_empl = new SimpleStringProperty(""); public Employees(){} public Employees(String id_empl, String surname_empl, String name_empl, String pathronymic_empl, String post_empl) { this.id_eml = new SimpleStringProperty(id_empl); this.surname_empl = new SimpleStringProperty(surname_empl); this.name_empl = new SimpleStringProperty(name_empl); this.pathronymic_empl = new SimpleStringProperty(pathronymic_empl); this.post_empl = new SimpleStringProperty(post_empl); } public String getId_eml() { return id_eml.get(); } Kesalahan: Caused by: java.lang.NullPointerException at controllers.AddEmployee.setEmployees(AddEmployee.java:39) at controllers.EmployeesController.onButtonPressedAction(EmployeesController.java:89)menunjuk ke tf_employee.setText(employees.getId_eml()); jendela itu sendiri: