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

Basic login example


In this section, we're going to write a simple example to show how things work in the new security API. Our example will be about a web page (servlet) that should be secured. A user should log in by providing a valid username and a password to be able to access the mentioned page.

In the new security API, this will be done as follows:

  1. Creating a web page to protect
  2. Mentioning who are allowed to access the web page
  3. Defining users and associated roles in a database
  4. Mapping security configuration to the user database

Creating a web page to protect

Let's start by creating a simple servlet that just welcomes the user to their home:

@WebServlet("/home") 
public class HomeServlet extends HttpServlet { 
 
    @Override 
    protected void doGet(HttpServletRequest req, HttpServletResponse 
    resp) 
            throws ServletException, IOException { 
        resp.getOutputStream().println("Welcome to your home!"); 
    } 
} 

Now, just try to access the resource by browsing /sec/home....