Introducing Generic Types : Generics Basics « Generics « Java Tutorial

  1. A generic type can accept parameters.
  2. A generic type is often called a parameterized type.
  3. You pass reference types in angle brackets to generic types.
List<E> myList;

E is called a type variable, namely a variable that will be replaced by a type.

  1. A generic type that uses a type variable E allows you to pass E when declaring or instantiating the generic type.
  2. If E is a class, you may also pass a subclass of E
  3. If E is an interface, you may also pass a class that implements E.
  4. By convention, you use a single uppercase letter for type variable names.

12.1.Generics Basics
12.1.1.Life without Generics
12.1.2.What Are Generics? A Simple Generics Example
12.1.3.Generics Work Only with Objects
12.1.4.A Generic Class with Two Type Parameters
12.1.5.Introducing Generic Types
12.1.6.Working with generic List
12.1.7.Nested generic type
12.1.8.A generic type can accept more than one type variables.
12.1.9.Raw Types and Legacy Code