IndexOutOfBoundsException Deleting Last Item from JList

[Rw Adams]

Ok, I am working a Java Swing JPanel where I am doing a database DELETE from a table. I have a JList control that is populated with the names of profiles from the database. I query the database for a list of Profiles that I then keep in an ArrayList. I copy the Profile Name from each ArrayList entries and add it to the DefaultListModel for the JList. My Panel has a "Delete" button that issues a DefaultListModel.remove() call and then issues the DELETE SQL statement to the Database. Everything works ok until I get to the last Profile that I want to delete. I get a message that the database delete went fine, but then I get the following IndexOutOfBoundsException:

2012-06-25 21:11:54,267 DEBUG [AWT-EventQueue-0] gui.EMMenuAction  (ProfilePanel.java:884)     - Selected Profile Ix: 0
2012-06-25 21:11:54,269 ERROR [AWT-EventQueue-0] Exception.AppHandleException (AppHandleException.java:29)     - java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
        at java.util.ArrayList.RangeCheck(ArrayList.java:547)
        at java.util.ArrayList.get(ArrayList.java:322)
        at app.db.AbstractDAO.getTableRow(AbstractDAO.java:169)
        at em.controller.EMProfControl.getProfile(EMProfControl.java:125)
        at em.gui.ProfilePanel$listSelectListener.valueChanged(ProfilePanel.java:886)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:167)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:147)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:194)
        at javax.swing.DefaultListSelectionModel.removeIndexInterval(DefaultListSelectionModel.java:660)
        at javax.swing.plaf.basic.BasicListUI$Handler.intervalRemoved(BasicListUI.java:2589)
        at javax.swing.AbstractListModel.fireIntervalRemoved(AbstractListModel.java:161)
        at javax.swing.DefaultListModel.remove(DefaultListModel.java:478)
        at em.gui.ProfilePanel.btnActnActionPerformed(ProfilePanel.java:626)
        at em.gui.ProfilePanel.access$400(ProfilePanel.java:24)
        at em.gui.ProfilePanel$2.actionPerformed(ProfilePanel.java:551)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6263)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2478)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

My Panel Class:

public class ProfilePanel extends javax.swing.JPanel {
    private ProfilePanel() {
        initComponents();
        listModel = new DefaultListModel();
        lstProfName.setModel(listModel);
        javax.swing.ListSelectionModel lstSelModel = lstProfName.getSelectionModel();
        lstSelModel.setSelectionMode(lstSelModel.SINGLE_SELECTION);
        lstSelModel.addListSelectionListener(new listSelectListener());
    
    }
    private void btnActnActionPerformed(java.awt.event.ActionEvent evt) {                                        

        String cmd = evt.getActionCommand();
        if (cmd.equals("ProfNewSave")) {
             profControl = em.controller.EMProfControl.getInstance();
             profControl.addProfile(listModel.getElementAt(0).toString(),
                 catMon.getText(), catTue.getText(), catWed.getText(),
                 catThu.getText(), catFri.getText(), catSat.getText(),
                 catSun.getText(), prepMon.getText(), prepTue.getText(),
                 prepWed.getText(), prepThu.getText(), prepFri.getText(),
                 prepSat.getText(), prepSun.getText());

            resetPanelFields();
            activateDocumentFilter(true);
            reinitPanel(EMFrame.PROF_NEW);
        } else if (cmd.equals("ProfDelete")) {
            profControl = em.controller.EMProfControl.getInstance();
            int indx = lstProfName.getSelectedIndex();
            if (indx != -1) {
                profControl.deleteProfile(indx);
//                if (indx >= listModel.size()) {
                listModel.remove(indx);
//                } else {
//                    listModel.removeListDataListener(null);
//                    listModel.removeAllElements();
//                }
                loggr.debug("ListModel size: "  + listModel.size());
                        }
        }

    }    
   private class listSelectListener implements javax.swing.event.ListSelectionListener {

        @Override
        public void valueChanged(javax.swing.event.ListSelectionEvent evt) {

            if (listModel.size() >= 0) {
            loggr.debug("Selected Profile Ix: " + evt.getFirstIndex());
            profControl = em.controller.EMProfControl.getInstance();
            profControl.getProfile(evt.getFirstIndex());
            }
        }
    }

From looking at the Stack Trace it looks like my DefaultListModel.remove() call (ProfilePanel.btnActnActionPerformed(ProfilePanel.java:626) is causing the valueChanged() method in listSelectListener to be fired (listSelectListener.valueChanged(ProfilePanel.java:886)). This causes my listener to try and locate an entry in what is an empty list, thus the IndexOutOfBoundsException. But I don't get why the listener is being executed because I deleted an Item from the list? I suppose I could remove the listSelectListener before I remove the list Entry but I am not sure this is a good idea. If I have "if listModel.size() > 0" in valueChanged method, then the Delete works Ok, but I can't add a New Profile because the same ListModel is being used for adding profiles. I am pretty sure I am doing something wrong, but I am not sure where I am going wrong.

Thanks for the help!

[Maneesh Godbole]

Put in a check for ListSelectionEvent#getValueIsAdjusting to avoid getting false positives on selection change.

[Michael Dunn]

unsure if this will work, but worth a try

private class listSelectListener implements javax.swing.event.ListSelectionListener {
    @Override
    public void valueChanged(javax.swing.event.ListSelectionEvent evt) {
       if(evt.getValueIsAdjusting() == false)//<----------------added
       {
         if (listModel.size() >= 0) {
           loggr.debug("Selected Profile Ix: " + evt.getFirstIndex());
           profControl = em.controller.EMProfControl.getInstance();
           profControl.getProfile(evt.getFirstIndex());
         }
       }//<---added
    }
}

[Maneesh Godbole]

Michael Dunn wrote:

if(evt.getValueIsAdjusting() == false)

I would rather

if(!evt.getValueIsAdjusting())

[Michael Dunn]

when reading code I often overlook the !
so prefer to have it stand out as == false

[Rw Adams]

Michael & Maneesh Thanks for the suggestions but I still get the error....

2012-06-26 17:59:01,155 ERROR [AWT-EventQueue-0] Exception.AppHandleException (AppHandleException.java:29)     - java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
        at java.util.ArrayList.RangeCheck(ArrayList.java:547)
        at java.util.ArrayList.get(ArrayList.java:322)
        at app.db.AbstractDAO.getTableRow(AbstractDAO.java:169)
        at em.controller.EMProfControl.getProfile(EMProfControl.java:125)
        at em.gui.ProfilePanel$listSelectListener.valueChanged(ProfilePanel.java:891)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:167)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:147)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:194)
        at javax.swing.DefaultListSelectionModel.removeIndexInterval(DefaultListSelectionModel.java:660)
        at javax.swing.plaf.basic.BasicListUI$Handler.intervalRemoved(BasicListUI.java:2589)
        at javax.swing.AbstractListModel.fireIntervalRemoved(AbstractListModel.java:161)
        at javax.swing.DefaultListModel.remove(DefaultListModel.java:478)
        at em.gui.ProfilePanel.btnActnActionPerformed(ProfilePanel.java:626)
        at em.gui.ProfilePanel.access$400(ProfilePanel.java:24)
        ........

Any other ideas appreciated, I am still stumped....

[Michael Dunn]

leave the getValueIsAdjusting() in the code and try your original fix "if listModel.size() > 0",
and see if there's still any side effects from add()