Simple Java Swing Program Of Plug-able Look & Feel Components In Java Swing

//Changing the look and feel of components
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.plaf.*;
class LookFeel extends JFrame implements ItemListener
{
 //vars
 JButton b;
 JCheckBox cb;
 JTextField t;
 JRadioButton r1, r2, r3;
 ButtonGroup bg;
 Container c;

 LookFeel()
 {
  //create content pane
  c = this.getContentPane();

  //set flow layout to c
  c.setLayout(null);

  //create components
  b = new JButton("Button");
  cb = new JCheckBox("CheckBox");
  t = new JTextField("TextField", 15);
  r1 = new JRadioButton("Metal");
  r2 = new JRadioButton("Motif");
  r3 = new JRadioButton("Windows");

  //create ButtonGroup object and add radio buttons to specify
  //that they belong to same group
  bg = new ButtonGroup();
  bg.add(r1);
  bg.add(r2);
  bg.add(r3);

  //set the location of components in content pane
  b.setBounds(100,50,75,40);
  cb.setBounds(100,100,100,40);
  t.setBounds(100,150,100,40);
  r1.setBounds(50,250,100,30);
  r2.setBounds(150,250,100,30);
  r3.setBounds(250,250,100,30);

  //add the components to content pane
  c.add(b);
  c.add(cb);
  c.add(t);
  c.add(r1);
  c.add(r2);
  c.add(r3);
  //add item listeners to radio buttons
  r1.addItemListener(this);
  r2.addItemListener(this);
  r3.addItemListener(this);

  //close the frame
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }

 public void itemStateChanged(ItemEvent ie)
 {
  
  try{
   //know which radio button is selected and accordingly change
   //the look and feel

  if(r1.getModel().isSelected())
  UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
  if(r2.getModel().isSelected())
  UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
  if(r3.getModel().isSelected())
  UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
 
  //change the look and feel in the content pane 
  SwingUtilities.updateComponentTreeUI(c);
  }catch(Exception e){}
  }

 public static void main(String args[])
 {
  //create the frame
  LookFeel lf = new LookFeel();
  lf.setSize(400,400);
  lf.setTitle("Look and Feel");
  lf.setVisible(true);
 }
}