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

Using interceptors


Interceptors, as the name suggests, are methods that intercept other methods. With interceptors, you can write one method that will always run before one or other methods of your choice. Interceptors are useful when you are required to implement some cross-cutting concern, which should take kind of a global effect on some other scenarios. For example, suppose you want to log each method call in a payment processor bean, so you can later check what really happened during runtime in production. The direct mechanism to implement this is to write a logging function, then call it in each method in the payment processing bean. Although this seems simple, it's really redundant with the existence of interceptors. With interceptors, you can write your logging function once, and attach it with all other methods that you need to associate logging with. Interceptors also allow you to access the original method invocation context; this means that you can access parameters passed to...