How This Book Is Organized

This book assumes that you will download the JDO distribution from the Java Community Process Web site (http://www.jcp.org/jsr/detail/12.jsp). In that distribution, you will find the JDO reference implementation, the JDO Javadoc, and the JDO specification. The JDO specification targets primarily those who write JDO implementations. In contrast, this book aims to provide application developers with the information that they need to use JDO.

This book is divided into two parts. The first part, and the bulk of the book, is intended to supplement the Javadoc by discussing the concepts and nuances of JDO from the application programmer's point of view. This part of the book is conceptual rather than hands-on. It will guide your understanding of JDO.

The second part of the book is primarily hands-on and examines the open source programs called the JDO Learning Tools. The JDO Learning Tools are programs that use JDO. There are two groups of programs in the JDO Learning Tools. The first group are atypical programs that explore the behavior of JDO. By using them, you can gain a deeper understanding of how JDO implementations behave.

The second group of programs in the JDO Learning Tools are simple but typical applications. They are intended to be exemplars for application architectures. Three architectures are considered in detail.

• Swing client/server applications

• Web applications that use JavaServer Pages and Java servlets

• Enterprise applications that use a JDO inside of Enterprise JavaBeans

The second part of the book discusses the application design issues and code patterns for each architecture. The discussion draws upon the concepts covered in the first part of the book.

The source code for the JDO Learning Tools is available from the publisher's Web site (http://www.apress.com) as well as from SourceForge.net (http://sourceforge.net/projects/jdo-tools). This book uses the 1.0 version of the JDO Learning Tools.

To run the tools and examples, you will need to download either the reference implementation of JDO or a trial version of a commercial implementation of JDO. Chapters 8 through 11 provide instructions for setting up your testing environment. The JDO Learning Tools provide build files for Kodo, Lido, IntelliBO, and the reference implementation. The JDO Learning Tools will evolve over time. You are encouraged to contribute improvements to make future releases of the JDO Learning Tools better for all of us.