JTabbedPane - ArrayIndexOutOfBoundsException

问题

Im adding and removing tabs in JTabbedPane dynamically. Code:

     //Method which adds new tab  
     private void addTab(String title, MainPanel panel) {
        tabbed.addTab(title, panel);
        int index = tabbed.indexOfComponent(panel);
        JPanel tabPanel = new JPanel();
        tabPanel.setOpaque(false);
        tabPanel.add(panel.getLabel());
        JButton closeButton = new JButton(new CloseTabAc(index));
        tabPanel.add(closeButton);
        panel.getLabel().setText(title);
        tabbed.setTabComponentAt(index, tabPanel);
        tabbed.setSelectedIndex(index);
        currentPanel = panel;
    }

//Action to close tab
private class CloseTabAc extends AbstractAction {

    private int tabNum;

    CloseTabAc(int tabNum) {
        putValue(Action.NAME, "x");
        this.tabNum = tabNum;
    }

    @Override
    public void actionPerformed(ActionEvent ev) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                MainPanel panel = (MainPanel) tabbed.getComponentAt(tabNum);
                tabbed.remove(tabNum);
            }
        });
    }
}

So this is the code. When switching, removing tabs I get this error:

Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
    at java.util.ArrayList.rangeCheck(ArrayList.java:604)
    at java.util.ArrayList.get(ArrayList.java:382)
    at javax.swing.JTabbedPane.getComponentAt(JTabbedPane.java:1224)
    at jnotepad.MainFrame$CloseTabAc$1.run(MainFrame.java:247)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:727)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    ...

Im trying to solve it few days but I dont see whats wrong. The only I saw this error occurs in situation when I open few tabs and close them randomly. So eg. I open 3 tabs: 1, 2 and 3. If I close them in order: 3, 2, 1 I get exception but everything close. But when I try to close them in order: 3, 1, 2 then 3 will close but on 1 exception will be thrown and it wont close now or then. So please help me solve my problem.

EDIT: I modified my code according to Jean's solution and now I get following exception:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
    at java.util.ArrayList.elementData(ArrayList.java:371)
    at java.util.ArrayList.get(ArrayList.java:384)
    at javax.swing.JTabbedPane.getComponentAt(JTabbedPane.java:1224)
    at jnotepad.MainFrame$ChangeHandler.stateChanged(MainFrame.java:228)
    at javax.swing.JTabbedPane.fireStateChanged(JTabbedPane.java:416)
    at javax.swing.JTabbedPane$ModelListener.stateChanged(JTabbedPane.java:270)
    ...

Looks exception is in line 228. It's my stateChanged listener:

   private class ChangeHandler implements ChangeListener {
        @Override
        public void stateChanged(ChangeEvent ev) {
            currentPanel = (MainPanel) tabbed.getComponentAt(tabbed.getSelectedIndex());
        }
    }

Every tab has MainPanel instance in it. When another tab is selected I get this panel and set is as currentPanel in MainFrame. This exception doesnt break my GUI as previous one but Id like to get rid of it.

回答1:

If you have three tabs

| tab 0 | tab 1 | tab 2 |

if you remove tab 1, tab 2 index will be 1. That's why you get a IndexOutOfBoundsException.

Pass a reference to the tab item, not its index on the tabbed pane, to the listener.

来源：https://stackoverflow.com/questions/15312252/jtabbedpane-arrayindexoutofboundsexception

标签

java

jtabbedpane