e811. creating a popup menu with nested menus.txt

这里面包含了一百多个JAVA源文件

final JPopupMenu popupMenu = new JPopupMenu();
    
    // Create a submenu with items
    JMenu submenu = new JMenu("SubMenu1");
    submenu.add(action1);
    submenu.add(action2);
    
    // Add submenu to popup menu
    popupMenu.add(submenu);