Как запомнить данные введенные форме JavaFX?

В форме ввода на javafx ввожу логин , как мне его запомнить в коде, чтобы использовать в других окнах . При использовании в другом окне Login.getText(); значение строки получаю null public class Login {

@FXML
private ResourceBundle resources;

@FXML
private URL location;

@FXML
private AnchorPane pale1;

@FXML
private PasswordField passPale;

@FXML
public TextField LoginPale;



public void setLoginPale(TextField loginPale) {
    LoginPale = loginPale;
}

public TextField getLoginPale() {
    return LoginPale;
}

@FXML
private Text label1;

@FXML
private Button bSingIn;

@FXML
private ImageView img2;

@FXML
private ImageView img3;

@FXML
private ImageView imgmain;

@FXML
private Text label2;

@FXML
private Button bSingUp;

@FXML
private Text label3;

@FXML
private ImageView imgkomp;






@FXML

public void g(){

  bSingIn.getScene().getWindow();
  FXMLLoader loader0= new FXMLLoader();
  loader0.setLocation(getClass().getResource("/sample/materials.fxml"));
  try {
      loader0.load();
  } catch (IOException e) {
      e.printStackTrace();
  }
  Parent root0 = loader0.getRoot();
  Stage stage0 = new Stage();
  stage0.setScene(new Scene(root0));
  stage0.showAndWait();

}

@FXML
void initialize() {

    bSingIn.setOnAction(

            actionEvent -> {
                try {
                    ResultSet result = Main.statement.executeQuery(
                            "SELECT id FROM usersStudents WHERE login=\'"+LoginPale.getText()+"\'AND passworduser=\'"+
                                    passPale.getText()+"\'");
                    if (result.next()){
                        g();
                    } else{
                        Alert alert = new Alert(Alert.AlertType.INFORMATION);
                        alert.setTitle("Error");
                        alert.setHeaderText(null);
                        alert.setContentText("Неправильный логин или пароль !");
                        alert.showAndWait();
                    }
                } catch (SQLException throwables) {
                    throwables.printStackTrace();
                }


            }

    );

    bSingUp.setOnAction(
            actionEvent -> {
                bSingIn.getScene().getWindow().hide();
                FXMLLoader loader11= new FXMLLoader();
                loader11.setLocation(getClass().getResource("/sample/second.fxml"));
                try {
                    loader11.load();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                Parent root = loader11.getRoot();
                Stage stage = new Stage();
                stage.setScene(new Scene(root));
                stage.show();
            }
    );
    assert pale1 != null : "fx:id=\"pale1\" was not injected: check your FXML file 'sample.fxml'.";
    assert passPale != null : "fx:id=\"passPale\" was not injected: check your FXML file 'sample.fxml'.";
    assert LoginPale != null : "fx:id=\"LoginPale\" was not injected: check your FXML file 'sample.fxml'.";
    assert label1 != null : "fx:id=\"label1\" was not injected: check your FXML file 'sample.fxml'.";
    assert bSingIn != null : "fx:id=\"bSingIn\" was not injected: check your FXML file 'sample.fxml'.";
    assert img2 != null : "fx:id=\"img2\" was not injected: check your FXML file 'sample.fxml'.";
    assert img3 != null : "fx:id=\"img3\" was not injected: check your FXML file 'sample.fxml'.";
    assert imgmain != null : "fx:id=\"imgmain\" was not injected: check your FXML file 'sample.fxml'.";
    assert label2 != null : "fx:id=\"label2\" was not injected: check your FXML file 'sample.fxml'.";
    assert bSingUp != null : "fx:id=\"bSingUp\" was not injected: check your FXML file 'sample.fxml'.";
    assert label3 != null : "fx:id=\"label3\" was not injected: check your FXML file 'sample.fxml'.";
    assert imgkomp != null : "fx:id=\"imgkomp\" was not injected: check your FXML file 'sample.fxml'.";

}

}