Chapter 17. Generic Programming
CHAPTER GOALS
To understand the objective of generic programming
To be able to implement generic classes and methods
To understand the execution of generic methods in the virtual machine
To know the limitations of generic programming in Java
Generic programming involves the design and implementation of data structures and algorithms that work for multiple types. You are already familiar with the generic ArrayList class that can be used to collect elements of arbitrary types. In this chapter, you will learn how to implement your own generic classes.
Generic Classes and Type Parameters
Generic programming is the creation of programming constructs that can be used with many different types. For example, the Java library programmers who implemented the ArrayList class used the technique of generic programming. As a result, you can form array lists that collect elements of different types, such as Array-List<String>, ArrayList<BankAccount>, and so on.
The LinkedList class that we implemented in Section 15.2 is also an example of generic programming—you can store objects of any class inside a LinkedList. That LinkedList class achieves genericity by using inheritance. It uses references of type Object and is therefore capable of storing objects of any class. In contrast, the Array-List class is a generic class: a class with a type parameter that is used to specify the type of the objects that you want to store. (Note that only our LinkedList implementation of
Get Big Java, 4th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
