Comment faire un menu deroulant en java?

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * Created on 19-avr.-07
 * 
 * @author: HackTrack
 */

public class DemoCombo extends JFrame {
	private Container c;
	private JLabel infoLabel;

	public DemoCombo() {
		super("Demo combo");
		initialize();
	}

	private void initialize() {
		c = getContentPane();
		c.setLayout(new BorderLayout());
		Person[] persons = new Person[3];
		persons[0] = new Person("hack", "track", 1);
		persons[1] = new Person("java","duke", 2);
		persons[2] = new Person("John", "Bowling", 3);
		DefaultComboBoxModel model = new DefaultComboBoxModel(persons);
		JComboBox combo = new JComboBox(model);
		combo.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent ae){
				Object o = ((JComboBox)ae.getSource()).getSelectedItem();
				Person p = (Person)o;
				infoLabel.setText("Sélection: [" + p.getId()+"] "+p.toString());
			}
			
		});
		c.add(combo, BorderLayout.NORTH);
		JPanel panel = new JPanel();
		panel.setPreferredSize(new Dimension(320, 200));
		infoLabel = new JLabel("Sélectionnez un item");
		panel.add(infoLabel);
		c.add(panel, BorderLayout.CENTER);
	}

	class Person {
		private String firstname;

		private String lastname;

		private int id;

		public Person(String firstname, String lastname, int id) {
			super();
			this.firstname = firstname;
			this.lastname = lastname;
			this.id = id;
		}

		public String toString() {
			StringBuffer buffer = new StringBuffer();
			buffer.append(lastname.toUpperCase()).append(" ");
			buffer.append(firstname.substring(0, 1).toUpperCase()).append(firstname.substring(1));
			return buffer.toString();
		}

		public int getId() {
			return id;
		}
	}

	public static void main(String[] args) {
		DemoCombo combo = new DemoCombo();
		combo.pack();
		combo.setVisible(true);
	}

}