Chapter 2. An Overview of JDO Interfaces

JDO's interfaces are defined in two packages: javax.jdo and javax.jdo.spi . You use the interfaces defined in the javax.jdo package to write your applications. This chapter introduces and describes each of these interfaces at a high level. Each method defined in these interfaces is covered thoroughly in this book. You can use the index to find information on a particular method.

The javax.jdo.spi package contains interfaces that JDO implementations use ( spi stands for service provider interface ). It is a common practice to have such a package that defines interfaces for use by the implementation of a Java API, distinct from the package that contains the interfaces for use of the API. You should not directly use any of the interfaces defined in javax.jdo.spi . We provide brief coverage of a few of the javax.jdo.spi interfaces that are directly involved in the management of persistent class instances. If you are interested in a thorough understanding of the interfaces in javax.jdo.spi , we encourage you to read the JDO specification.

We conclude this chapter by enumerating the optional features in JDO.