JOptiopane multi select

I wil select multiple values from an JOptionpane in Java. What is the solution to get these multiple values out of this pane. When I tried always got only one value back while i selected two or more selections.

String bigList[] = new String[bankReferentie.aantalKlanten()];

for (int i = 0; i < bigList.length; i++) {
    bigList[i] = bankReferentie.getKlanten(i).toString();
}

JOptionPane.showMessageDialog(null, new JList(bigList), "Rekening", JOptionPane.PLAIN_MESSAGE);

The trick here is to create a JList before showing the option pane, then query it after the option pane is shown.

import java.awt.BorderLayout;
import java.util.List;
import javax.swing.*;

class MultiSelectListInOptionPane {

    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                JPanel gui = new JPanel(new BorderLayout());

                String[] fruit = {"Apple", "Banana", "Grapefruit", "Orange"};
                JList<String> list = new JList<String>(fruit);
                gui.add(new JScrollPane(list));

                JOptionPane.showMessageDialog(
                        null, 
                        gui,
                        "Rekening",
                        JOptionPane.QUESTION_MESSAGE);
                List items = (List)list.getSelectedValuesList();
                for (Object item : items) {
                    System.out.println("Selected: " + item);
                }
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency
        SwingUtilities.invokeLater(r);
    }
}

E.G. Output

run:
Selected: Banana
Selected: Orange
BUILD SUCCESSFUL (total time: 7 seconds)