java how to make a gui

1import java.awt.BorderLayout;
2import java.awt.event.ActionEvent;
3import java.awt.event.ActionListener;
4
5import javax.swing.JButton;
6import javax.swing.JFrame;
7import javax.swing.JTextArea;
8
9public class Foo{
10
11  public static void main(String[] args) {
12
13    JFrame f = new JFrame("A JFrame");
14    f.setSize(250, 250);
15    f.setLocation(300,200);
16    final JTextArea textArea = new JTextArea(10, 40);
17    f.getContentPane().add(BorderLayout.CENTER, textArea);
18    final JButton button = new JButton("Click Me");
19    f.getContentPane().add(BorderLayout.SOUTH, button);
20    button.addActionListener(new ActionListener() {
21
22        @Override
23        public void actionPerformed(ActionEvent e) {
24            textArea.append("Button was clicked\n");
25
26        }
27    });
28
29    f.setVisible(true);
30
31  }
32
33}