Example Program with a Button

Here is an example program that adds a button to a frame.

import java.awt.*; 
import javax.swing.*;

class ButtonFrame extends JFrame
{
  JButton bChange ; // reference to the button object

  // constructor for ButtonFrame
  ButtonFrame(String title) 
  {
    super( title );                     // invoke the JFrame constructor
    setLayout( new FlowLayout() );      // set the layout manager

    bChange = new JButton("Click Me!"); // construct a JButton
    add( bChange );                     // add the button to the JFrame
    setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );   
  }
}

public class ButtonDemo
{
  public static void main ( String[] args )
  {
    ButtonFrame frm = new ButtonFrame("Button Demo");

    frm.setSize( 150, 75 );     
    frm.setVisible( true );   
  }
}

new JButton("Click Me!") constructs a button object and puts the words "Click Me!" on it. The add() method of the frame puts the JButton into the frame.