a custom JavaFX numeric textbox

NumberTextField.java

public class NumberTextField extends TextField {

    @Override
    public void replaceText(int start, int end, String text)
    {
        if (validate(text))
        {
            super.replaceText(start, end, text);
        }
    }

    @Override
    public void replaceSelection(String text)
    {
        if (validate(text))
        {
            super.replaceSelection(text);
        }
    }

    private boolean validate(String text)
    {
        if (text.matches("[0-9]") || text == "")
        {
            return true;
        }
        return false;
    }
}