javafx 或 fxml 中有什么方法可以验证 TextField 字符的长度吗?

Is there any way in javafx or fxml to validate TextField character's length?

不接受除数字 [0-9] 以外的任何字符及其长度的文本字段,在我的例子中它是 11,但在正则表达式中添加 {11} 后文本字段不接受任何东西。请帮忙!

代码在这里:

public class NumberField extends JFXTextField {

        @Override
        public void replaceText(int i, int i1, String string){

            if (string.matches("[0-9]{11}") || string.isEmpty()) //{11} is length of number
                super.replaceText(i , i1 , string);

        }
public class ContactField extends JFXTextField {

    /*
     *
     * i is current length / value
     * i1 is previous length / value
     * string is value / char i-e currently keytyped
     *
     * Here:
     *
     * string.matches[0-9], it matches single current key typed value to the regex expression(one at a time)
     * string.empty() is used for backspace key
     */
    @Override
    public void replaceText(int i, int i1, String string) {
         if ((string.matches("[0-9]") || string.isEmpty()) && i <= 10) //for validating numbers length start from 0;
             super.replaceText(i, i1, string);
         }

    /*
     * It maintains prev and current values when selected char( by arrows keys like from middle) is deleted;
     *
     */
    @Override
    public void replaceSelection(String replacement) {
        super.replaceSelection(replacement);
    }
}