Book Image

Java EE 8 Application Development

Book Image

Java EE 8 Application Development

Overview of this book

Java EE is an Enterprise Java standard. Applications written to comply with the Java EE specification do not tie developers to a specific vendor; instead they can be deployed to any Java EE compliant application server. With this book, you’ll get all the tools and techniques you need to build robust and scalable applications in Java EE 8. This book covers all the major Java EE 8 APIs including JSF 2.3, Enterprise JavaBeans (EJB) 3.2, Contexts and Dependency Injection (CDI) 2.0, the Java API for WebSockets, JAX-RS 2.1, Servlet 4.0, and more. The book begins by introducing you to Java EE 8 application development and goes on to cover all the major Java EE 8 APIs. It goes beyond the basics to develop Java EE applications that can be deployed to any Java EE 8 compliant application server. It also introduces advanced topics such as JSON-P and JSON-B, the Java APIs for JSON processing, and the Java API for JSON binding. These topics dive deep, explaining how the two APIs (the Model API and the Streaming API) are used to process JSON data. Moving on, we cover additional Java EE APIs, such as the Java API for Websocket and the Java Message Service (JMS), which allows loosely coupled, asynchronous communication. Further on, you’ll discover ways to secure Java EE applications by taking advantage of the new Java EE Security API. Finally, you’ll learn more about the RESTful web service development using the latest JAX-RS 2.1 specification. You’ll also get to know techniques to develop cloud-ready microservices in Java EE.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Chapter 4. Enterprise JavaBeans

Enterprise JavaBeans are server-side components that encapsulate the business logic of an application. Enterprise JavaBeans (EJB) simplify application development by automatically taking care of transaction management and security. There are two types of Enterprise JavaBean: session beans, which perform business logic, and message-driven beans, which act as a message listener.

Readers familiar with previous versions of J2EE will notice that entity beans were not mentioned in the preceding paragraph. In Java EE 5, entity beans were deprecated in favor of the Java Persistence API (JPA). Entity beans are still supported for backwards compatibility; however, the preferred way of doing Object Relational Mapping (ORM) is through the JPA.

The following topics will be covered in this chapter:

  • Session beans
  • A simple session bean
  • A more realistic example
  • Using a session bean to implement the DAO design pattern
    • Singleton session beans
  • Message-driven beans
  • Transactions in enterprise...