Raw types were common before generics were introduced in Java 5. Today, developers typically use raw types for compatibility with legacy code or interoperability with non-generic APIs.

Java generic classes are compiled into bytecodes, assuming java.lang.Object for all type parameters (or, alternatively, a more specific class constraint). This is known as "type erasure".

Event-driven design has been around for quite some time. Within Java, both AWT (Abstract Window Toolkit) and Swing are based on an event model. Java provides the classes EventQueue, AWTEvent ...