JMenuItem

JMenuItem is a component in the Swing GUI toolkit that represents a selectable item within menus. It is used inside menus such as JMenu and JPopupMenu and serves as a leaf item that triggers an action when chosen. JMenuItem extends AbstractButton, implements Accessible, and relies on a UI delegate to render its appearance.

A JMenuItem can display text and an icon, and it supports keyboard shortcuts through a mnemonic or an accelerator. The mnemonic provides a mnemonic key for quick access when the menu is open, while the accelerator assigns a global keyboard shortcut. The item can be enabled or disabled, have a tooltip, and be associated with an Action, allowing the item to inherit properties like name, icon, and enabled state from the Action.

Events are delivered to registered listeners when the item is selected by the user. The common pattern is to attach an ActionListener or bind the item to an Action, so performing the menu action triggers application logic. JMenuItem changes can also be synchronized with an Action, so updates to the Action propagate to the menu item.

JMenuItem has specialized subclasses for different menu behaviors, including JCheckBoxMenuItem for toggleable states and JRadioButtonMenuItem for mutually exclusive selections. It is typically used within a JMenu that groups related items, while other components like JMenu and JPopupMenu organize the overall menu structure. Accessibility support is provided through the standard Swing Accessible framework.