Add JList Data on Selecting a Radio Button

Here is some code displays a different JList content depending on which radio button is selected.

First here are the forms

---

here is the code. It uses validate() and repaint() methods on the JFrame to refresh the form

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JRadioButton;


public class mainForm extends JFrame implements ItemListener{
 private JPanel panel;
 private JPanel listPanel;
 private JPanel borderPanel;
 private JRadioButton one;
 private JRadioButton two;
 private JList list;
 private String[] arrayOne= new String[]{"Monday", "Tuesday", "Wednesday"};
 private String[] arrayTwo=new String[]{"Thursday", "Friday", "Saturday"};
 
 public mainForm(){
  CreatePanel();
  this.add(borderPanel);
  this.setBounds(100, 100, 200, 200);
  this.setVisible(true);
 }
 
 private void CreatePanel(){
  panel=new JPanel();
  borderPanel=new JPanel(new BorderLayout());
  
  one=new JRadioButton("one");
  one.addItemListener(this);
  two=new JRadioButton("two");
  two.addItemListener(this);
  list=new JList();
  
  ButtonGroup group = new ButtonGroup();
  group.add(one);
  group.add(two);
  
  panel.add(one);
  panel.add(two);
  listPanel=new JPanel();
  listPanel.add(list);
  
  borderPanel.add(panel, BorderLayout.CENTER);
  borderPanel.add(listPanel, BorderLayout.SOUTH);
  
 }

 @Override
 public void itemStateChanged(ItemEvent arg0) {

  
  Object source = arg0.getSource();
  if(source.equals(one)){
   
   list.removeAll();
   list.setListData(arrayOne);
   
   
  }
  else{
   list.removeAll();
   list.setListData(arrayTwo);
  }
  
  //borderPanel.add(listPanel, BorderLayout.SOUTH);
  //this.add(borderPanel);
  this.validate();
  this.repaint(); 
 }
 
 
}