Book Image

Java 9 with JShell

By : Gaston C. Hillar
Book Image

Java 9 with JShell

By: Gaston C. Hillar

Overview of this book

The release of Java 9 has brought many subtle and not-so-subtle changes to the way in which Java programmers approach their code. The most important ones are definitely the availability of a REPL, known as JShell, which will make experiments and prototyping much more straightforward than the old IDE-based project-led approach. Another, more subtle change can be seen in the module system, which will lead to more modularized, maintainable code. The techniques to take full advantage of object-oriented code, functional programming and the new modularity features in Java 9 form the main subjects of this book. Each chapter will add to the full picture of Java 9 programming starting out with classes and instances and ending with generics and modularity in Java.
Table of Contents (23 chapters)
Java 9 with JShell
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Declaring subclasses that inherit the implementation of interfaces


We have the SocialAnimal abstract class that implements both the Sociable and Comparable<Sociable> interfaces. We cannot create instances of this abstract class. Now, we will create a concrete subclass of SocialAnimal named SocialLion. The class declares a constructor that ends up calling the constructor defined in the superclass. The class implements the four abstract methods declared in its superclass to return the appropriate values for a lion that will participate in a party. The code file for the sample is included in the java_9_oop_chapter_10_01 folder, in the example10_01.java file.

public class SocialLion extends SocialAnimal {
    public SocialLion(String name, int age) {
        super(name, age);
    }

    @Override
    public String getDanceRepresentation() {
        return "*-* ^\\/^ (-)";
    }

    @Override
    public String getFirstSoundInWords() {
        return "Roar";
    }

    @Override
    public...