Restrict TextArea using Unicode with Java

Question

I have a TextArea that I am trying to restrict user inputs to allow only IP addresses format in that Area. So I thought of only allowing digits and decimal points. For multiple IPs, One IP per line, so the TextArea needs to accept new lines. For the most part what I have below is working except for delete. I can't delete any entry even if I am using the associate Unicode. I am running MAC OS 10, not sure if it makes any difference or not but the info is out there just in case.

public class RestrictIpInputTextArea extends TextArea {

    @Override
   public void replaceText(int i, int il, String string){
       if(string.matches("[0-9_\\u000A_\\u232B_\\u0008_\\u2421_._\\u007F]") || string.isEmpty()){
          super.replaceText(il, il, string);
       }
   }

    @Override
    public void replaceSelection(String string) {
        super.replaceSelection(string); 
    }

Answer 1

I was able to find out the solution for it. Visit the link below for more reference. http://docs.oracle.com/javafx/2/ui_controls/custom.htm However, I still want to explore TextFormatter function deployed in JavaFX 8U40

public class numericValue extends TextArea {
@Override
public void replaceText(int start, int end, String text) {
    String old = getText();
    if (text.matches("[0-9_._\\u000A]*")) {
        super.replaceText(start, end, text);
    }
}
@Override
public void replaceSelection(String text) {
    String old = getText();
    if (text.matches("[0-9_._\\u000A]*")) {
        super.replaceSelection(text);
    }
}
}