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

public class SwingGui extends JFrame {

    JFrame f = new JFrame();
    JButton pageStart = new JButton("PAGE_START");
    JButton pageEnd = new JButton("PAGE_END");
    JButton center = new JButton("CENTER");
    JButton lineStart = new JButton("LINE_START");
    JButton lineEnd = new JButton("LINE_END");

    public SwingGui() {
        FlowLayout fl = new FlowLayout();
        fl.addLayoutComponent("LS", lineStart);
        fl.addLayoutComponent("LE", lineEnd);
        fl.setAlignment(FlowLayout.CENTER);

        Panel panel = new Panel(fl);

        f.setTitle("JFrame");
        f.getContentPane().setLayout(new BorderLayout());
        f.getContentPane().add(pageStart, BorderLayout.NORTH);
        f.getContentPane().add(center,    BorderLayout.CENTER);
        f.getContentPane().add(pageEnd,   BorderLayout.EAST);
        f.getContentPane().add(lineStart, BorderLayout.WEST);
        //f.getContentPane().add(lineEnd,   BorderLayout.SOUTH);
        f.getContentPane().add(panel, BorderLayout.SOUTH);
        f.setSize(300,200);
        f.setVisible(true);
        f.pack();
    }

    public static void main(String[] args) {
        new SwingGui();
    }
}