Book Image

Hands-On Design Patterns with Java

By : Dr. Edward Lavieri
2 (1)
Book Image

Hands-On Design Patterns with Java

2 (1)
By: Dr. Edward Lavieri

Overview of this book

Java design patterns are reusable and proven solutions to software design problems. This book covers over 60 battle-tested design patterns used by developers to create functional, reusable, and flexible software. Hands-On Design Patterns with Java starts with an introduction to the Unified Modeling Language (UML), and delves into class and object diagrams with the help of detailed examples. You'll study concepts and approaches to object-oriented programming (OOP) and OOP design patterns to build robust applications. As you advance, you'll explore the categories of GOF design patterns, such as behavioral, creational, and structural, that help you improve code readability and enable large-scale reuse of software. You’ll also discover how to work effectively with microservices and serverless architectures by using cloud design patterns, each of which is thoroughly explained and accompanied by real-world programming solutions. By the end of the book, you’ll be able to speed up your software development process using the right design patterns, and you’ll be comfortable working on scalable and maintainable projects of any size.
Table of Contents (15 chapters)
Free Chapter
1
Section 1: Introducing Design Patterns
4
Section 2: Original Design Patterns
8
Section 3: New Design Patterns

Understanding the visitor pattern

The visitor design pattern allows us to perform operations on an object without altering its structure. Essentially, we can add functionalities to an object with it changing the original object structure. An example is when a person goes to a hair salon and asks for a haircut. Once in the chair, the parameters of what is desired are changed. This does not change the structure of the operation; it just adds new functionality such as having hair colored as well as cut and styled.

Using object-oriented programming, we can extend the visitor design pattern so it affects the way inheritance works. We can extend a class and then add functionality to it in a child class.