Setting the displayed text in a JList

Question

I have created a JList by passing it a class that implements the interface ListModel (thank you, Gita Weiner). When the JList is displayed, it shows a cryptical representation of the entries in the class. For example: leeftijd.Persoon@6190b689. (Each entry in the list is an object of type Persoon). How can I show (some of) the attributes of each Persoon object? Class Persoon has attributes First Name and Last Name. I would like to displat that information in the form 'Last Name, First Name'.
The code looks like this:
public class LeeftijdList extends JFrame {
     LeeftijdList(Personenlijst eenPersonenLijst) {
          super("Leeftijd");
          setSize(300, 300);
          JPanel pane = new JPanel();
          FlowLayout lm = new FlowLayout();
          pane.setLayout(lm);
          JList dataList = new JList(eenPersonenLijst);
          JScrollPane scrollPane = new JScrollPane(dataList);
          scrollPane.getViewport().setView(dataList);
          pane.add(scrollPane);
          setContentPane(pane);
     public static void main(String[] arguments) {
          Personenlijst lijst = new Personenlijst();
          lijst.init();
          JFrame frame = new LeeftijdList(lijst);
          ExitWindow exit = new ExitWindow();
          frame.addWindowListener(exit);
          frame.show();
}Note: I don't really understand the line scrollPane.getViewport().setView(dataList). I took it from a code snippet in the API specification.

Answer 1

The default renderer of JList simply uses the toString() method of the Object in the list. What you see is the the default toString() implementation of the Object class which I believe is the memory address of the Object.
Solution. Implement the toString() method in your Object or provide a custom renderer for the JList.
This posting shows both of the above concepts for a JComboBox althought the concept is exactly the same:
http://forum.java.sun.com/thread.jspa?forumID=57&threadID=613731