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

public class GridLayoutDemo extends JFrame implements ActionListener{
	private JButton buttons[];
	private Container container;
	private GridLayout grid1;
	//GUI 구성
	public GridLayoutDemo()
	{
		super("Random numbers ver.1");
		//레이아웃을 구성한다.
		grid1 = new GridLayout(5,5);

		//컨텐트 패인을 얻고 레이아웃을 설정한다.
		container = getContentPane();
		container.setLayout(grid1);
		//메뉴
		JMenu fileMenu = new JMenu("File");
		fileMenu.setMnemonic('F');
		//Exit 메뉴 
		JMenuItem exitItem = new JMenuItem("Exit");
		exitItem.setMnemonic('x');
		fileMenu.add(exitItem);
		exitItem.addActionListener(
				new ActionListener() {
					//클릭하면 종료
					public void actionPerformed(ActionEvent event)
					{
						System.exit(0);
					}
				}
				);
		//메뉴바 부착
		JMenuBar bar = new JMenuBar();
		setJMenuBar(bar);
		bar.add(fileMenu);
		
		
		//버튼을 생성하여 추가한다.
		buttons = new JButton[25];
		
		for(int count = 0; count < 25; count++) {
			buttons[count] = new JButton(Integer.toString(count));
			buttons[count].addActionListener(this);
			container.add(buttons[count]);
		}
		setSize(500,500);
		setVisible(true);
	}
	
	public void actionPerformed(ActionEvent event)
	{
		container.validate();
	}
	public static void main(String[] args) {
		GridLayoutDemo application = new GridLayoutDemo();
		application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

	}

}