@Override
    public void start(Stage stage) {
        final DatePicker datePicker = new DatePicker(LocalDate.now());

        DateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");
        dateFormat.setLenient(false);        
        DateStringConverter converter = new DateStringConverter(dateFormat);                
        
        TextFormatter<Date> formatter = new TextFormatter<>(converter, null, c -> {
                        
            if (c.isContentChange()) {
                // auto parse
                if (c.getControlNewText().length() == 10) {
                    try {
                        dateFormat.parse(c.getControlNewText());
                    } catch (ParseException ex) {
                        c.getControl().setStyle("-fx-background-color: red;");
                    }
                }
                else{
                    c.getControl().setStyle(null);
                }
            }
            if (c.isAdded()) {
                // length restriction
                if (c.getControlNewText().length() > 10)
                {                    
                    return null;
                }
                
                // auto mask
                int caretPosition = c.getCaretPosition();
                if (caretPosition == 2 || caretPosition == 5) {
                    c.setText(c.getText() + ".");
                    c.setCaretPosition(c.getControlNewText().length());
                    c.setAnchor(c.getControlNewText().length());
                }
            }
            return c;
        });
        datePicker.getEditor().setTextFormatter(formatter);
            
        datePicker.setOnAction(event -> {
            LocalDate date = datePicker.getValue();
            System.out.println("Selected date: " + date);
        });

        stage.setScene(
                new Scene(datePicker)
        );
        stage.show();
    }