Java Data Objects

The javax.jdo Package

The javax.jdo package contains all the interfaces you should use:

• PersistenceManager

• PersistenceManagerFactory

• Transaction

• Extent

• Query

• InstanceCallbacks

It also contains the JDOHelper class and a set of exception classes.

This is the complete set of JDO application interfaces! JDO has a relatively small API, allowing you to learn it quickly and become productive applying it. JDO uses your Java classes as the data model for representing and managing data, which is major contributing factor in its simplicity and ease of use.

Every method in each of these interfaces is described somewhere in this book. We introduce basic JDO concepts first and gradually progress to more advanced topics. Semantically related methods are often covered in the same section, but coverage of the methods for a particular interface is usually dispersed throughout the text. Appendix C provides the signature for every method in each interface. The index provides a reference to each place in the book where a method is covered. Here’s a brief description of each interface in the package:

PersistenceManager

PersistenceManager is your primary interface when using JDO. It provides methods to create query and transaction objects, and it manages the lifecycle of persistent instances. Each chapter introduces a few PersistenceManager methods. The interface is used for the basic and advanced features in JDO.

PersistenceManagerFactory

The PersistenceManagerFactory is responsible for configuring and creating ...