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

Receiving parameters


Like any programming function, web services may, and most will be passed various parameters. In JAX-RS, there are different types of parameters that can be passed, including:

  • Query parameters
  • Path parameters
  • Form parameters
  • Matrix parameters
  • Header parameters

Query parameters

Query parameters are those parameters encoded as a part of the URL by tailing the URL with the question mark symbol ?, followed by key-value pairs of parameters separated by ampersands, &, for example, http://example.com/add?num1=5&num2=6.

This URL contains two query parameters, called num1 and num2. The values of these parameters are 5 and 6 respectively. The question mark symbol denotes that the rest of the URL is a set of query parameters, separated by ampersands as mentioned earlier. Each parameter has a name, followed by the equals symbol =, followed by the value. If the name or the value has special characters (for example, a question mark, ampersand, equals sign, spaces, or any other URL...