Book Image

Practical Design Patterns for Java Developers

By : Miroslav Wengner
Book Image

Practical Design Patterns for Java Developers

By: Miroslav Wengner

Overview of this book

Design patterns are proven solutions to standard problems in software design and development, allowing you to create reusable, flexible, and maintainable code. This book enables you to upskill by understanding popular patterns to evolve into a proficient software developer. You’ll start by exploring the Java platform to understand and implement design patterns. Then, using various examples, you’ll create different types of vehicles or their parts to enable clarity in design pattern thinking, along with developing new vehicle instances using dedicated design patterns to make the process consistent. As you progress, you’ll find out how to extend vehicle functionalities and keep the code base structure and behavior clean and shiny. Concurrency plays an important role in application design, and you'll learn how to employ a such design patterns with the visualization of thread interaction. The concluding chapters will help you identify and understand anti-pattern utilization in the early stages of development to address refactoring smoothly. The book covers the use of Java 17+ features such as pattern matching, switch cases, and instances of enhancements to enable productivity. By the end of this book, you’ll have gained practical knowledge of design patterns in Java and be able to apply them to address common design problems.
Table of Contents (14 chapters)
1
Part 1: Design Patterns and Java Platform Functionalities
4
Part 2: Implementing Standard Design Patterns Using Java Programming
8
Part 3: Other Essential Patterns and Anti-Patterns

Discovering multiple inheritance in Java with the twin pattern

This pattern allows you to combine functions of objects that tend to be used together, which is a common paradigm used by languages without multiple inheritance support.

Motivation

The twin pattern presents the possibility to implement multiple inheritance in Java. Multiple inheritance is not a supported concept as it may lead to compiler inconsistency, known as the diamond problem. The diamond problem defines a state through class abstraction where the compiler may turn out to be inconsistent. This state is due to the lack of information due to multiple abstract classes. The compiler does not have enough information about which methods should execute.

Sample code

This pattern is not supported by the platform and is rarely required for development. For these reasons, the pattern most likely does not exist inside the released JDK, as described. However, let us examine a possible example to better understand the...