Organization

This book has 17 chapters and 5 appendixes. The first three chapters provide a good overview, showing a complete example, a high-level overview of the JDO interfaces, and a discussion of the architectures in which JDO can be used. Chapter 3 through Chapter 6 deal with object modeling, schema design, and aspects of the JDO software-development process. Chapter 7 covers aspects of establishing a JDO runtime environment, which includes connecting to a datastore and issuing transactions. The remaining chapters cover aspects of using JDO to store, access, and query instances in the datastore. We start by presenting the basic concepts and gradually move to more advanced topics, including features that are optional in JDO implementations. We complete the book by discussing how you can integrate your applications into application-server and J2EE environments.

The following list provides a brief description of each chapter and appendix:

Chapter 1

Provides an introductory overview of JDO by walking through a small application that illustrates many of JDO's capabilities.

Chapter 2

Provides a high-level introduction to all of JDO's interfaces. Details of these interfaces are covered in the rest of the book. We also discuss class enhancement and the optional features in JDO.

Chapter 3

Provides a description of the architectural components within a single JDO application and also describes the various system architectures in which JDO implementations have been deployed.

Chapter 4

JDO maps your object models into a database. This chapter covers the Java object-modeling capabilities supported by JDO.

Chapter 5

Explains approaches used for mapping your Java object models to the modeling components of the underlying datastore.

Chapter 6

Covers the process and effects of enhancing your classes.

Chapter 7

Explains how to establish a connection with a datastore and establish a transaction context in which to access objects in the database.

Chapter 8

Covers all aspects of the CRUD operations of using a database: Create, Read, Update, and Delete. We show how to make objects persistent, accessing them from the database via extents and navigation, and how to modify and delete them.

Chapter 9

JDO includes its own query language, which is based largely on Java, using its operators and syntax to access objects using the data model defined by your classes.

Chapter 10

Identifies the various approaches for uniquely identifying an object in the database.

Chapter 11

Covers the lifecycle states used by a JDO implementation to manage objects in memory, describing the state transitions that occur as your application and the JDO implemenation perform operations on the objects.

Chapter 12

Describes transactional fields, null values in fields, special facilities that control the access of fields, and mechanisms for you to manage fields during certain lifecycle events. The chapter concludes with a discussion of first- and second-class objects.

Chapter 13

Covers advanced topics related to managing instances in the cache, including making persistent instances transient, making transient instances transactional, cloning instances, and refreshing and evicting instances in the cache.

Chapter 14

Covers techniques for accessing instances outside of a transaction.

Chapter 15

Covers all aspects of optimistic transactions in JDO.

Chapter 16

Explains how to use JDO in an application-server environment.

Chapter 17

Explains the use of JDO in an Enterprise Java Beans environment, using JDO as the persistence service for session and entity beans, using either bean-managed persistence (BMP) or container-managed persistence (CMP).

Appendix A

Provides a table containing all the lifecycle states and all transitions that occur for any operation that changes the state of an instance.

Appendix B

Provides the XML Document Type Descriptor (DTD) for JDO metadata.

Appendix C

Provides the signature for all the methods in each JDO interface.

Appendix D

Provides the Backus-Naur Form (BNF) for the JDO Query Language.

Appendix E

Provides complete source code for the major classes used in the examples throughout the book.