Book Image

Kotlin for Enterprise Applications using Java EE

By : Raghavendra Rao K
Book Image

Kotlin for Enterprise Applications using Java EE

By: Raghavendra Rao K

Overview of this book

Kotlin was developed with a view to solving programmers’ difficulties and operational challenges. This book guides you in making Kotlin and Java EE work in unison to build enterprise-grade applications. Together, they can be used to create services of any size with just a few lines of code and let you focus on the business logic. Kotlin for Enterprise Applications using Java EE begins with a brief tour of Kotlin and helps you understand what makes it a popular and reasonable choice of programming language for application development, followed by its incorporation in the Java EE platform. We will then learn how to build applications using the Java Persistence API (JPA) and Enterprise JavaBeans (EJB), as well as develop RESTful web services and MicroServices. As we work our way through the chapters, we’ll use various performance improvement and monitoring tools for your application and see how they optimize real-world applications. At each step along the way, we will see how easy it is to develop enterprise applications in Kotlin. By the end of this book, we will have learned design patterns and how to implement them using Kotlin.
Table of Contents (13 chapters)

Using Kotlin with Java

We will now discuss how to work with Kotlin and Java in the project that we created.

In this section, we will learn how to use Kotlin in an existing Java project, and Java in an existing Kotlin project.

One of Kotlin's important features is its interoperability with Java. If we have an existing Java project, we can add new code in Kotlin or we can convert the existing Java code to Kotlin.

Kotlin in an existing Java project

Let's look at an example of how to add Kotlin code to an existing Java project created using Maven. We have created a simple Maven project that has some code written in Java. This is shown here:

We can add Kotlin code to it as follows.

  1. Right-click on src/main/java and...