Book Image

Learn Java with Projects

By : Dr. Seán Kennedy, Maaike van Putten
5 (3)
Book Image

Learn Java with Projects

5 (3)
By: Dr. Seán Kennedy, Maaike van Putten

Overview of this book

Learn Java with Projects stands out in the world of Java guides; while some books skim the surface and others get lost in too much detail, this one finds a nice middle ground. You’ll begin by exploring the fundamentals of Java, from its primitive data types through to loops and arrays. Next, you’ll move on to object-oriented programming (OOP), where you’ll get to grips with key topics such as classes, objects, encapsulation, inheritance, polymorphism, interfaces, and more. The chapters are designed in a way that focuses on topics that really matter in real-life work situations. No extra fluff here, so that you get more time to spend on the basics and form a solid foundation. As you make progress, you’ll learn advanced topics including generics, collections, lambda expressions, streams and concurrency. This book doesn't just talk about theory—it shows you how things work with little projects, which eventually add up to one big project that brings it all together. By the end of this Java book, you’ll have sound practical knowledge of Java and a helpful guide to walk you through the important parts of Java.
Table of Contents (22 chapters)
1
Part 1: Java Fundamentals
9
Part 2: Object-Oriented Programming
15
Part 3: Advanced Topics

Appreciating records

Records are a special type of class, and are considered “data carriers”. They help us avoid typing in copious amounts of boilerplate code. Records are specified using a record declaration where you list the components of the record. Implicitly generated in the background are a canonical constructor; toString, equals, and hashCode methods and public accessor methods for each of the components specified. The accessor methods take on the same names as the components themselves (as opposed to the more traditional get methods). Records are best explained by contrasting them to regular classes. Figure 8.29 presents a normal class with a lot of boilerplate code:

Figure 8.29 - A class with a lot of boilerplate code

Figure 8.29 - A class with a lot of boilerplate code

The Person class in the preceding figure is customized somewhat to map to a record more easily. For example, the class itself is final (line 5) and the instance variables, namely name and age (lines 6-7), are also...