The GoF Design Patterns published in 1998 qualifies as a classic still being taught in universities and recommended as best practice in the industry. In his deep dive session from Devoxx, Venkat Subra ...

A given row in that component can be assigned a color. Initially, this was done through control-clicking in the row, which brought up the color chooser, and returned the new color.

The Observable design pattern is used in many important Java APIs. One well-known example is a JButton that uses the ActionListener API to execute an action.