Comment faire de la liaison bidirectionnelle

import java.text.Format;

import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.util.converter.IntegerStringConverter;

public class BiderectionalBinding {

    public static void main(String[] args) {
        SimpleIntegerProperty intProp = new SimpleIntegerProperty();
        SimpleStringProperty textProp = new SimpleStringProperty();

        Bindings.bindBidirectional(textProp, intProp, new IntegerStringConverter());

        intProp.set(2);
        System.out.println(textProp);

        textProp.set("8");
        System.out.println(intProp);    
    }
}
nabil