Remove last item from JList

From:
CBO <christopher_board@yahoo.co.uk>
Newsgroups:
comp.lang.java.help
Date:
Mon, 14 Jul 2008 02:11:53 -0700 (PDT)
Message-ID:
<a037d43a-c861-42a2-87a0-0c8c56e547cd@l64g2000hse.googlegroups.com>
Hi all,

I am currently developing a java application that reads in a file and
populates the information inside the data file into a JList. I want
the user to be able to select an item from the JList and then they are
able to delete the item which rewrites the new data to the the file
and repopulates the JList.

This method works fine until there is only one item remaining inside
the JList. The problem is when the user presses delete the item is
removed from JList but an error is produced and the new data is not
written to the file i.e. to make it empty.

Below is the error message that is displayed:

Exception occurred during event dispatching:
java.util.NoSuchElementException
    at java.util.StringTokenizer.nextToken(Unknown Source)
    at
remoteshutdown.ExceptionsList.btnDelete_actionPerformed(ExceptionsList.java:
228)
    at
remoteshutdown.ExceptionsList_btnDelete_actionAdapter.actionPerformed(ExceptionsList.java:
273)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown
Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown
Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.Dialog$1.run(Unknown Source)
    at java.awt.Dialog$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.Dialog.show(Unknown Source)
    at java.awt.Component.show(Unknown Source)
    at java.awt.Component.setVisible(Unknown Source)
    at java.awt.Window.setVisible(Unknown Source)
    at java.awt.Dialog.setVisible(Unknown Source)
    at
remoteshutdown.mainScreen.jMenuOptionsExceptions_actionPerformed(mainScreen.java:
979)
    at remoteshutdown.mainScreen
$mainScreen_jMenuOptionsExceptions_ActionAdapter.actionPerformed(mainScreen.java:
1145)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.AbstractButton.doClick(Unknown Source)
    at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
    at javax.swing.plaf.basic.BasicMenuItemUI
$Handler.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown
Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown
Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

Below is the code that I am using:

    public void btnDelete_actionPerformed(ActionEvent e) {
        this.lstComputerExceptions.getModel();
        if (lstComputerExceptions.getSelectedIndices().length > 0) {
            int[] tmp = this.lstComputerExceptions.getSelectedIndices();
            int[] selectedIndicies =
lstComputerExceptions.getSelectedIndices();
            for (int i = tmp.length - 1; i >= 0; i--) {
                selectedIndicies = lstComputerExceptions.getSelectedIndices();
                model.removeElementAt(selectedIndicies[i]);
            }
            String computerName = model.toString();
            StringTokenizer st = new StringTokenizer(computerName, "[]");

// if (computerName != null) {

// } else {
                String tokenizedString = st.nextToken();
                String newComputers = tokenizedString.replace(",", "\n");
                System.out.println(newComputers);
                try {
                    BufferedWriter out = new BufferedWriter(
                            new FileWriter(
                                    "C:\\Documents and Settings\\All Users\\Application Data\
\Remote Shutdown\\ExceptionsList.csv",
                                    false));
                    out.write(newComputers);
                    out.write("\n");
                    out.close();
                } catch (IOException ex) {
                    statusBar.setForeground(Color.red);
                    statusBar
                            .setText("Failed to modify file. Please ensure the file is not
open");
                    System.err.println("Unable to delete: " + ex.toString());
                }
            }
    }

I know what the problem is but I am just not sure how I can fix this
issue from happing:

Any help in this matter would be highly appreciated.

Thank you

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