9781430246923 (1430246928), Apress, 2013
When we set out to write this book, our goal was to present Enterprise JavaBeans (EJB) to developers, with a keen
eye toward how this technology can be used in everyday, real-world applications. JSR-345: Enterprise JavaBeansTM,
Version 3.2 EJB Core Contracts and Requirements is a deep spec that addresses the needs of beginning developers and
hardcore power users alike. That’s a large audience to satisfy and, as a reference guide, the EJB spec document covers
it well. In writing a book about how to use EJB, we had to narrow our audience; nonetheless, we believe that we’ve
written a book that will serve the needs of a majority of Java EE developers.
This book is targeted at developers who are experienced with Java, have built single- or multi-tier applications
using earlier versions of EJB or other technologies, and are ready to take on the challenges (and rewards) of building
enterprise applications using standards-based technology. Recognizing that a combined 1,100 pages of reference
material [covering the EJB and Java Persistence API (JPA) specs] can be daunting, we have provided an on-ramp for
developers, unfolding EJB one section at a time, and giving you the information and code examples you need to roll
up your sleeves and get to work.
As each chapter unfolds, you will not only learn about a new area of the spec, but you will also learn through
specific examples about how to apply it to your own applications. Many of these examples come directly from the
comprehensive, end-to-end, Java EE Enterprise Wines Online application constructed in Chapter 7 and Chapter 12,
so that you can see how they fit into a bigger picture. You are encouraged to take these examples and run with them.
Try them out in your favorite IDE or development environment, and change them around and try new things. EJB and
the related APIs covered in this book—JPA, Web Services, and Contexts and Dependency Injection (CDI)—offer you
a lot with which to work. Once you’re comfortable with the basics of building, deploying, and testing, you’ll find that
EJB components are not only powerful, but also easy to build and use.
Together, the authors of this book have built a number of applications using EJB in concert with other
technologies in the Java EE stack, and we have attempted to capture within it advice about the practical patterns we
have learned, the strategies we have found successful, and some pitfalls you can avoid. Most chapters in this book
are dedicated to exploring specific areas of EJB, but we have also included chapters on Java Persistence API (JPA),
Contexts and Dependency Injection (CDI), Web Services, gauging the performance of your EJB applications, and
deploying to the Java EE application server of your choice. An introductory “Getting Started” section at the end of this
chapter will get you set up to run the many useful sample applications found at the end of each chapter in the book.
We hope this book will serve not only as a reference guide for information on EJB but also as a how-to guide and
repository of practical examples to which you can refer back as you build your own applications. Enjoy!