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)

Transactions

As you may know, transactions are sets of indivisible operations that either succeed or roll back. Transactions in a messaging system are used to group the messages logically. When we send a group of messages in a transaction to a queue or topic, we either commit them or we roll them back. This means that the messages are either all delivered in one go or they are rolled back. On the consumer or receiver side, the messages are all either consumed and acknowledged or rolled back.

Let's take a closer look. When messages are sent in a transaction, the messages are not sent to the messaging provider, in our case the GlassFish server queue/topic, until we invoke the commit() function on the jmsContext as shown in the following diagram:

On the consuming side, when transactions are enabled, the messages will be removed from the queue or topic only when they are committed...