Handling events is an important part of any user interface so here's a few links to
- Find out about handling key events by Using the KeyListener interface.
- Listen for focus events by Implementing the FocusListener interface.
- Handle mouse events in this step-by-step guide How to Handle Mouse Events which looks at the MouseListener, MouseMotionListener and MouseWheelListener interfaces.
- Handle Item Events using the ItemListener interface with a JComboBox.