Book Image

Learning Java by Building Android Games - Second Edition

By : John Horton
Book Image

Learning Java by Building Android Games - Second Edition

By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems presently. It uses the most popular programming language, Java, as the primary language for building apps of all types. However, this book is unlike other Android books in that it doesn’t assume that you already have Java proficiency. This new and expanded second edition of Learning Java by Building Android Games shows you how to start building Android games from scratch. The difficulty level will grow steadily as you explore key Java topics, such as variables, loops, methods, object oriented programming, and design patterns, including code and examples that are written for Java 9 and Android P. At each stage, you will put what you’ve learned into practice by developing a game. You will build games such as Minesweeper, Retro Pong, Bullet Hell, and Classic Snake and Scrolling Shooter games. In the later chapters, you will create a time-trial, open-world platform game. By the end of the book, you will not only have grasped Java and Android but will also have developed six cool games for the Android platform.
Table of Contents (30 chapters)
Learning Java by Building Android Games Second Edition
Contributors
Preface
Index

Inheritance mini-app


We have looked at the way we can create hierarchies of classes to model the system which fits our game. So, let's try out some simple code that uses inheritance. The completed code is in the chapter 8 folder of the code download. It is called InheritanceExample.

Create a new project called Inheritance. Create three new classes in the usual way. Name one AlienShip, another Fighter, and the last one Bomber.

Next is the code for the AlienShip class. It is very similar to our previous class demo AlienShip. The differences are that the constructor now takes an int parameter which it uses to set the shield strength.

The constructor also outputs a message to the logcat window, so we can see when it is being used. The AlienShip class also has a new method, fireWeapon that is declared abstract. This guarantees that any class that subclasses AlienShip must implement their own version of fireWeapon. Notice the class has the abstract keyword as part of its declaration. We must do...