Program to use GridBagLayout in Java

// Program to use GridBagLayout.
import java.awt.*;
import java.awt.event.*;
public class GridBagLayoutDemo1 extends Frame
{
GridBagLayout gb;
GridBagConstraints gbc;
Button b1, b2, b3, b4, b5, b6, b7;
public GridBagLayoutDemo1( String s )
{
 super( s );
   
 gb = new GridBagLayout();
 gbc = new GridBagConstraints();
 setLayout( gb );
 b1 = new Button( "B1" );
 b2 = new Button( "B2" );
 b3 = new Button( "B3" );
 b4 = new Button( "B4" );
 b5 = new Button( "B5" );
 b6 = new Button( "B6" );
 b7 = new Button( "B7" );
 gbc.gridx = 0;
 gbc.gridy = 0;
 gbc.gridwidth = 1;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b1, gbc );  
 gbc.gridx = 1;
 gbc.gridy = 0;
 gbc.gridwidth = 2;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b2, gbc );
 gbc.gridx = 0;
 gbc.gridy = 1;
 gbc.gridwidth = 1;
 gbc.gridheight = 2;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b3, gbc );
 gbc.gridx = 1;
 gbc.gridy = 1;
 gbc.gridwidth = 2;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b4, gbc );
 gbc.gridx = 1;
 gbc.gridy = 2;
 gbc.gridwidth = 1;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b5, gbc );
 gbc.gridx = 2;
 gbc.gridy = 2;
 gbc.gridwidth = 1;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b6, gbc );
 gbc.gridx = 0;
 gbc.gridy = 3;
 gbc.gridwidth = 3;
 gbc.gridheight = 1;
 gbc.weightx = 1; 
 gbc.weighty = 1;
 gbc.fill = GridBagConstraints.BOTH;
 gb.setConstraints( b7, gbc );
 add( b1 );
 add( b2 );
 add( b3 );
 add( b4 );
 add( b5 );
 add( b6 );
 add( b7 );
 setVisible( true );
 setSize( 300, 200 );
}
public static void main( String args[ ] )
{
 GridBagLayoutDemo1 g = new GridBagLayoutDemo1( "GridBag Layout" );
 g.addWindowListener( new WindowAdapter()
 {
        public void windowClosing( WindowEvent we )
  {
   System.exit( 0 );
  }
 } );
}
}