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)

Implementing the chain of responsibility pattern

The chain-of-responsibility pattern is a behavioral pattern that decouples a request from a handling object in a chain of handlers until the handler is recognized as processing the request. This pattern avoids tight coupling between the sender and the receiver, and gives more than one chance to handle the request.

With this pattern, requests are sent to a sequential chain of potential handlers. One of the handlers is expected to take the request and return the response. If the request is not accepted by any of the handlers, it will not be handled by the application. This is depicted by the following diagram:

Each of the handlers handles a single responsibility, which makes the design cleaner, loosely coupled, and easy to extend.

This pattern is useful when we want to perform different operations based on a request as well as keeping...