Using and Understanding Java Data Objects is the programmer's guide to JDO. Adopted by the Java Community Process, Java Data Objects (JDO) specifies a universal and transparent persistence service for Java objects. JDO reduces the amount of code that application developers write to store and retrieve persistent state. JDO frees application designers and programmers from the details of persistence. As a result, designs can be more object-oriented, programmers can be more productive, and applications can be more robust and flexible. This book provides you with the insight to evaluate and use JDO. It begins by explaining the concepts and terminology of JDO. It describes in detail the JDO interfaces and classes that you will use to build an application. Throughout, the book probes in depth. It identifies the specification's blemishes so you can avoid relying on behavior that is not defined. It offers coding strategies to solve common problems. It proposes working designs for common application architectures, such as client/server Swing applications, web applications, and five flavors of Enterprise JavaBeans. The last four chapters provide a tutorial on the JDO Learning Tools, a suite of open source programs that explore JDO and exemplify its use. Using the JDO Learning Tools, you can take a JDO implementation for a test drive and examine the architecture and code of several sample applications.