import java.awt.FlowLayout;

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");

    public MainWindow() {
        this.setLayout(new FlowLayout());
        this.add(button1);
        this.add(button2);
        this.add(button3);
        this.setTitle("FlowLayout");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }    
}