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 template method pattern


The template method pattern, as the name suggests, provides a template for code, which can be filled in by developers implementing different functionalities. The easiest way to understand this is to think in terms of HTML templates. Most of the websites you visit follow some kind of template. For example, there is usually a header, a footer, and a sidebar, and in between, we have the core content. That means the template is defined with a header, footer, and sidebars, and every content writer can use this template to add their content.

Intent

The idea of using the template method pattern is to avoid writing duplicate code so that developers can focus on core logic.

Implementation

The template method pattern is best implemented using an abstract class. The areas for which we know about the implementation will be provided; the default implementation and the areas that are to be kept open for implementation are marked abstract.

For example, think of a database fetch query...