Book Image

Design Patterns and Best Practices in Java

By : Kamalmeet Singh, Adrian Ianculescu, Lucian-Paul Torje
Book Image

Design Patterns and Best Practices in Java

By: Kamalmeet Singh, Adrian Ianculescu, Lucian-Paul Torje

Overview of this book

Having a knowledge of design patterns enables you, as a developer, to improve your code base, promote code reuse, and make the architecture more robust. As languages evolve, new features take time to fully understand before they are adopted en masse. The mission of this book is to ease the adoption of the latest trends and provide good practices for programmers. We focus on showing you the practical aspects of smarter coding in Java. We'll start off by going over object-oriented (OOP) and functional programming (FP) paradigms, moving on to describe the most frequently used design patterns in their classical format and explain how Java’s functional programming features are changing them. You will learn to enhance implementations by mixing OOP and FP, and finally get to know about the reactive programming model, where FP and OOP are used in conjunction with a view to writing better code. Gradually, the book will show you the latest trends in architecture, moving from MVC to microservices and serverless architecture. We will finish off by highlighting the new Java features and best practices. By the end of the book, you will be able to efficiently address common problems faced while developing applications and be comfortable working on scalable and maintainable projects of any size.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

The chain-of-responsibility pattern


Computer software is for processing information, and there are different ways of structuring and processing that information. We already know that when we talk about object-oriented programming, we should assign a single responsibility to each class in order to make our design easy to extend and maintain.

Consider a scenario where multiple types of operations can be performed on a set of data that comes with a client request. Instead of adding information about all the operations in a single class, we can maintain different classes responsible for the different types of operations. This helps us keep our code loosely coupled and clean.

These classes are called handlers. The first handler will receive the request and take a call if it needs to perform an action, or pass it on to the second handler. Similarly, the second handler checks and can pass on the request to the next handler in the chain.

Intent

The chain-of-responsibility pattern chains the handlers...