is there a way to make selections permanent on a JList

问题

I am trying to device a way to make a list selected items not change, that is, the selections are final. Only newly added or non clicked items can be changed but not the ones which have already been clicked and are already in the list. Following is an example by mKorbel (see answer 8). Is there a way to make the selections permanent on this example? THNX!

import java.awt.Component;
import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import javax.swing.*;

public class Ctrl_Down_JList {

    private static void createAndShowUI() {
        String[] items = {"Sun", "Mon", "Tues", "Wed", "Thurs", "Fri", "Sat"};
        JList myJList = new JList(items) {

            private static final long serialVersionUID = 1L;

            @Override
            protected void processMouseEvent(MouseEvent e) {
                int modifiers = e.getModifiers() | InputEvent.CTRL_MASK;
                // change the modifiers to believe that control key is down
                int modifiersEx = e.getModifiersEx() | InputEvent.CTRL_MASK;
                // can I use this anywhere?  I don't see how to change the modifiersEx of the MouseEvent
                MouseEvent myME = new MouseEvent((Component) e.getSource(), e.getID(), e.getWhen(), modifiers, e.getX(),
                        e.getY(), e.getXOnScreen(), e.getYOnScreen(), e.getClickCount(), e.isPopupTrigger(), e.getButton());
                super.processMouseEvent(myME);
            }
        };
        JFrame frame = new JFrame("Ctrl_Down_JList");
        frame.getContentPane().add(new JScrollPane(myJList));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowUI();
            }
        });
    }

来源：https://stackoverflow.com/questions/19206496/is-there-a-way-to-make-selections-permanent-on-a-jlist