Book Image

Developing Middleware in Java EE 8

Book Image

Developing Middleware in Java EE 8

Overview of this book

Middleware is the infrastructure in software based applications that enables businesses to solve problems, operate more efficiently, and make money. As the use of middleware extends beyond a single application, the importance of having it written by experts increases substantially. This book will help you become an expert in developing middleware for a variety of applications. The book starts off by exploring the latest Java EE 8 APIs with newer features and managing dependencies with CDI 2.0. You will learn to implement object-to-relational mapping using JPA 2.1 and validate data using bean validation. You will also work with different types of EJB to develop business logic, and with design RESTful APIs by utilizing different HTTP methods and activating JAX-RS features in enterprise applications. You will learn to secure your middleware with Java Security 1.0 and implement various authentication techniques, such as OAuth authentication. In the concluding chapters, you will use various test technologies, such as JUnit and Mockito, to test applications, and Docker to deploy your enterprise applications. By the end of the book, you will be proficient in developing robust, effective, and distributed middleware for your business.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Writing your first REST service


In the following sections, we are going to create our first REST service. Creating a REST service in JAX-RS requires the following two steps:

  1. Writing a resource class: A class where we will write our web services methods
  2. Configuring Jersey for our project: Telling the application server to load Jersey, and referencing the resource class we will be creating

Writing a resource class

A resource class is the primary building block of RESTful services in JAX-RS. It's a POJO that includes one or more resource methods. Each resource method represents a RESTful service that can be called using one of the main core HTTP methods (GET, POST, PUT, or DELETE).

In order to create a resource class, you will add the @Path annotation to your POJO. The annotation is passed a relative URI that represents the URL of your RESTful service. You will introduce one or more method, annotated with one of the method designator annotations (@GET,@POST,@PUT, or@DELETE).

Let's see an example...