Java Swing Application

import java.lang*

public class Test1
{
   public static void main(String args[])
   {
     System.out.println("Hello World...");
   }

}

Use Look and Feel in Java Swing Application

With the help of Look & Feel you can change GUI of your Swing Application.

First we know that what is the meaning of Look and Feel in this context,

Look refers to the appearance of GUI widgets of Swing like JLabel,JButton,JPanel,JFrame etc.

and 

Feels refers to the behavior of Widgets like OnSelected,Pressed,MouseOver etc.

Available Look and Feels, 

     Oracle JRE provides follwing look and feels

1.  CrossPlatformLookAndFeel - this is also called Metal look and feel, it is a default L &  F. If you   don't  set any look and feel then this look and feel will show.
2.  SystemLookAndFeel
3. Synth—the basis for creating your own look and feel with an XML file.
4.  Multiplexing— a way to have the UI methods delegate to a number of different look and feel implementations at the same time.