Lesson: Generics

by Gilad Bracha

Introduced in J2SE 5.0, this long-awaited enhancement to the type system allows a type or method to operate on objects of various types while providing compile-time type safety. It adds compile-time type safety to the Collections Framework and eliminates the drudgery of casting.

Introduction

Defining Simple Generics

Generics and Subtyping

Wildcards

Generic Methods

Interoperating with Legacy Code

The Fine Print

Class Literals as Runtime-Type Tokens

More Fun with Wildcards

Converting Legacy Code to Use Generics

Acknowledgements