Summary

This chapter examines three miscellaneous aspects of JDO. The JDOHelper class provides utility methods that perform housekeeping chores, offer convenience methods, and aid in debugging. The InstanceCallbacks interface provides callback methods that notify the application when JDO acts on a persistent object. The various JDO exceptions allow robust applications to provide recovery, reporting, and integration within the existing error handling framework.

This chapter concludes the examination of the JDO persistence service for Java objects. The next four chapters examine the example code found in the JDO Learning Tools, an open source set of tools and examples that use JDO. The next chapter describes the learning programs that you can use to both test drive a JDO implementation and learn more about the behavior of JDO.