Book Image

Introduction to JVM Languages

Book Image

Introduction to JVM Languages

Overview of this book

Anyone who knows software development knows about the Java Virtual Machine. The Java Virtual Machine is responsible for interpreting Java byte code and translating it into actions. In the beginning, Java was the only programming language used for the JVM. But increasing complexity of the language and the remarkable performance of the JVM created an opening for a new generation of programming languages. If you want to build a strong foundation with the Java Virtual Machine and get started with popular modern programming languages, then this book is for you. The book will begin with a general introduction of the JVM and its features, which are common to the JVM languages, helping you get abreast with its concepts. It will then dive into explaining languages such as Java, Scala, Clojure, Kotlin, and Groovy and will show how to work with each language, their features, use cases, and pros and cons. By writing example projects in those languages and focusing on each language’s strong points, it will help you find the programming language that is most appropriate for your particular needs. By the end of the book, you will have written multiple programs that run on the Java Virtual Machine and know about the differences between the various languages.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Chapter 4. Java Programming

With a lot of theory behind us, let's write a real Java program. We will write a simple standalone web service that will count the frequency of each character that was used in the passed input string and return this in a JSON dictionary. We will use the Gradle build tool to automatically fetch dependencies from the internet and then build and run the project. At the coding stage of the backend class, we will use a test-driven approach and write unit tests along the way. In every step, from the coding stage to running the final web service, we will use Eclipse IDE. In the end, we'll discuss various shortcuts to ensure you are as productive as possible. We'll cover the following topics:

  • Configuring Eclipse IDE
  • Creating a new Gradle-based project in Eclipse IDE
  • Modifying the Gradle build script
  • Building the project
  • Coding the backend class
  • Creating unit tests to test the backend class
  • Writing a web service
  • Running a web service