Can't perform JMenuItem action in JPopupMenu without getting thrown a java.lang.ClassCastException

I am attempting to have a JFrame window hide itself and create a tray icon whenever it is closed instead of exiting. The tray icon should then have two menu items able to make the JFrame window visible again and to exit it entirely respectively. The former works properly, but when attempting to perform an action from a JMenuItem from the tray icon's JPopupMenu, I am thrown the following exception:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: class javax.swing.JMenuItem cannot be cast to class javax.swing.JFrame (javax.swing.JMenuItem and javax.swing.JFrame are in module java.desktop of loader 'bootstrap')
at Hierophant$5.actionPerformed(Hierophant.java:94)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.AbstractButton.doClick(AbstractButton.java:369)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1020)
at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1064)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6636)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6401)
at java.desktop/java.awt.Container.processEvent(Container.java:2263)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5012)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4919)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4548)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4489)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2764)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4844)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Here is the relevant section of code controlling minimization behavior and the JPopupMenu. It's being run in a method with no parameter formatters inside a public class extending JFrame.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
setDefaultCloseOperation(WindowConstants.HIDE_ON_CLOSE);
SystemTray tray = SystemTray.getSystemTray();
JPopupMenu menu = new JPopupMenu();
JMenuItem show = new JMenuItem("Show");
JMenuItem exit = new JMenuItem("Exit");
icon = Toolkit.getDefaultToolkit().getImage("icon.png");
trayIcon = new TrayIcon(icon, "Hierophant");
show.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
((JFrame)e.getSource()).setExtendedState(JFrame.NORMAL);
((JFrame)e.getSource()).setExtendedState(((JFrame)e.getSource()).getExtendedState() & (~JFrame.ICONIFIED));
pack();
}
});
exit.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
((JFrame)e.getSource()).dispose();
}
});
menu.add(show);
menu.addSeparator();
menu.add(exit);
trayIcon = new TrayIcon(icon, "Hierophant");
trayIcon.setImageAutoSize(true);
trayIcon.addMouseListener(new MouseAdapter() {
public void showPopup(MouseEvent e) {
if (e.isPopupTrigger()) {
menu.setLocation(e.getX(), e.getY());
menu.setInvoker(menu);
menu.setVisible(true);
}
}
@Override
public void mouseReleased(MouseEvent e) {
showPopup(e);
}
public void mousePressed(MouseEvent e) {
showPopup(e);
}
});
try {
tray.add(trayIcon);
} catch (AWTException e) {
e.printStackTrace();
}
addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
((JFrame)e.getSource()).setExtendedState(JFrame.ICONIFIED);
((JFrame)e.getSource()).setExtendedState(((JFrame)e.getSource()).getExtendedState() | JFrame.ICONIFIED);
}
});

The code probably isn't the prettiest, but I'm still at a loss as to what is causing Java to throw this exception. Is there some place in particular where I've messed up?

As commenters have pointed out, JFrame definitely isn't the source of your event.

If you want this exact code to not throw the exception, you could simply catch the exception whenever you call the cast to JFrame:

try
{
    (JFrame) e.getSource(); 
}
catch(ClassCastException e)
{
    // nothing
}

What you probably want to do is getting the Component which is the event source and then get the Parent Container of that Component.

It could look something like this:

if(e.getSource() instanceof Component)
{
    Component component = (Component) e.getSource();

    if(component.getParent() instanceof JFrame)
    {
        JFrame frame = (JFrame) component;

        frame.setExtendedState(JFrame.NORMAL);
    }
}

> The former works properly, but when attempting to perform an action from a JMenuItem from the tray icon's JPopupMenu, I am thrown the following exception:...

The former works because you add the WindowListener to the JFrame.

The latter doesn't work because you add the ActionListener to the JMenuItem.

> ... Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: class javax.swing.JMenuItem cannot be cast to class javax.swing.JFrame

What do you find confusing about that Exception? If you click on a JMenuItem why do you think you can treat the source of ActionEvent as a JFrame?

Your question in the forum should be: How can I access the frame given a JMenuItem?

In response to that your can try:

JMenuItem menuItem = (JMenuItem)e.getSource();
Window window = SwingUtilitiels.windowForComponent( menuItem );
window.dispose();