For menus.
For all components.
None if large icon and small icon are not equal.
Can be used for status bars, for example.
Default: java.awt.event.KeyEvent.VK_UNDEFINED, i.e., no mnemonic key.
Default: java.awt.event.KeyEvent.VK_UNDEFINED, i.e., no mnemonic key. For all buttons and thus menu items.
Title is not optional.
For all components.
An abstract action to be performed in reaction to user input.
Not every action component will honor every property of its action. An action itself can generally be configured so that certain properties should be ignored and instead taken from the component directly. In the end, it is up to a component which property it uses in which way.
javax.swing.Action