import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JFrame;

public class MainWindow extends JFrame {
    JButton button1 = new JButton("gomb1");
    JButton button2 = new JButton("gomb2");
    JButton button3 = new JButton("gomb3");
    JButton button4 = new JButton("gomb4");
    JButton button5 = new JButton("gomb5");

    GridBagLayout layout = new GridBagLayout();
    GridBagConstraints c = new GridBagConstraints();

    public MainWindow() {
        this.setLayout(new GridBagLayout());

        this.c.fill = GridBagConstraints.HORIZONTAL;
        this.c.gridx = 0;
        this.c.gridy = 0;        
        this.add(button1, c);

        this.c.gridx = 1;
        this.c.gridy = 0;        
        this.add(button2, c);

        this.c.gridx = 2;
        this.c.gridy = 0;
        this.add(button3, c);

        this.c.gridx = 0;
        this.c.gridy = 1;        
        this.c.gridwidth = 3;
        this.add(button4, c);

        this.c.gridx = 0;
        this.c.gridy = 2;
        this.c.gridwidth = 3;
        this.c.ipady = 40;   
        this.add(button5, c);

        this.setTitle("GridBagLayout");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }
}