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

Custom responses


As discussed earlier, any response from a RESTful service may include:

  • Status code
  • Response entity
  • Content type

By default, any RESTful service that runs and returns normally without any problems will contain the status code 200 (OK). The response entity will be these value you return from the RESTful method. The content type will be these one specified by the @Produces annotation, as mentioned earlier.

Sometimes, you may need to customize the details of the response yourself at runtime, in one of the following scenarios:

  •  The response entity data type/MIME content type is not known until runtime
  •  A custom status code should be returned to the client according to some business logic inside the RESTful service code

In JAX-RS, you can customize the response at runtime by following two steps:

  1.  Declaring the return type of the method to be of type Response
  2.  Building a custom response object from inside your RESTful service code and returning it to the client

Building a response object...