What This Book Is About

This book is about:

• Everything JDO, in that the book provides an in-depth explanation about the technology

• Applying JDO in applications ranging from standalone programs to J2EE components

• The best practices in designing and developing applications that use JDO

Part One ”Introduction

Chapter 1: JDO Overview

Java Data Objects is a new standard for persistence in Java applications. JDO is well placed to change the fundamental way in which architects and developers approach the design and development of persistence in Java applications. This chapter gives you an insight into the concepts around which JDO is centered.

Chapter 2: Object Persistence Fundamentals

Chapter 2 looks at what's technically behind object persistence. It explains and compares different ways to implement persistence frameworks. It takes a broad view of the JDBC-based object-relational mapping solutions and outlines the effort of implementing such a framework from scratch.

Part Two ”The Details

Chapter 3: Getting Started with JDO

This chapter explains the basics of how JDO works and how to use JDO to create, read, update, and delete persistent objects. It introduces some of the advanced concepts behind JDO and aims to provide sufficient understanding to allow a Java programmer to develop an application using JDO.

Chapter 4: Lifecycles

This chapter discusses the lifecycle of objects and the reasons why state changes can be meaningful to the application developer. A closer look is taken at mandatory and optional states of instances, the methods to gather information about states, and methods that lead to state transitions.

Chapter 5: Developing with JDO

This chapter looks at fundamental JDO concepts and all the classes and APIs defined by the JDO specification. It explains each of the methods for interfaces like the PersistenceManager, the JDOHelper, and I18NHelper classes, overviews JDO exception classes, and the classes and interfaces in the service provider interface package.

Chapter 6: Finding Your Data

This chapter discusses the query facility provided by JDO specification. The techniques surrounding the retrieval and querying of the underlying datatstore using the API and the JDOQL (JDO Query Language) are discussed with detailed examples.

Chapter 7: Architecture Scenarios

This chapter outlines the different types of application architectures that can be used with JDO. It covers when to use JDO versus JDBC, different types of datastores that can be used with JDO, using JDO with multi- tier applications, and using multi-threaded programming with JDO.

Part Three ”J2EE

Chapter 8: JDO and the J2EE Connector Architecture

This chapter explains how JDO can be used in conjunction with J2EE via the J2EE Connector Architecture (JCA). After a brief introduction to JCA, this chapter looks at how JCA fits together with JDO and how they can be used together to build J2EE applications.

Chapter 9: JDO and Enterprise JavaBeans ( EJB )

This chapter looks at the Enterprise JavaBeans (EJB) component model and its relationship to JDO. It addresses various implementation topics and provides extensive source code examples. The goal of this chapter is not to simply show 'how' to code EJB and JDO together, but also to help you decide if the combination of these two APIs makes sense for you.

Chapter 10: Security

This chapter defines the different levels of security, their requirements, and their objectives. It looks at the Reference Enhancer, and examines the rules and measures defined by JDO to secure an application. Finally, the chapter looks at application-level security and how J2EE and JDO work together regarding security.

Chapter 11: Transactions

This chapter looks at some fundamental concepts around transactions in Java, the transaction capabilities included in JDO, and how they can be used in standalone applications and in conjunction with Java Transaction APIs (JTA) in managed environments. It also outlines design considerations and practices when using JDO in a transactional manner.

Part Four ”The Conclusion

Chapter 12 ” JDO and Java Database Connectivity ( JDBC )

This chapter reviews the JDBC API, gives a brief overview of relational databases, looks at the history of JDBC, and provides an introduction to the new JDBC 3.0 API. The second part of the chapter compares JDBC with JDO, discusses features and differences of each, and highlights common misconceptions.

Chapter 13: Best Practices

This chapter provides some suggestions, usage guidelines, and best practices for using JDO successfully in typical real-world enterprise business applications.

Chapter 14: Current Status and the Road Ahead

This chapter provides the reader with a possible roadmap and the direction that JDO is likely to take. Features covered in this chapter are in no way guaranteed to make it into JDO 2.0, nor do they represent the limit of new features that may be considered . Rather, this chapter aims to give some insight into what may appear in future revisions of the JDO specification.

Chapter 15: Case Study

This chapter discusses a complete working example of the "Core JDO Library" to put come context around material covered in this book and to give the reader an insight into how applications can be developed with JDO. The "Core JDO Library" application is an implementation of a couple of use cases to explain basic and advanced JDO features. It is also meant to explain concepts mentioned in the previous chapters such as two-tier and n-tier applications. The chapter is divided into smaller sections that can be used as cook-book style recipes.

Appendix A : JDO States

Appendix B : JDO Metadata XML DTD

Appendix C : JDOQL BNF

Appendix D : PersistenceManagerFactory Quick Reference

Appendix E : JDO Vendors