Core Java™ Data Objects

10.2. Implementing PersistenceCapable

To make transparent persistence possible, the JDO specification defines the contract between PersistenceCapable, the interface that all persistent classes have to implement, and PersistenceManager, the central interface of a JDO implementation. But don't worry, how a JDO implementation works inside is not explained in this chapter. Because JDO gets direct access privileges for fields and classes, the contract is examined under security aspects. On the one hand, the PersistenceManager must be able to read and write fields and gather information about persistence-capable classes, like field types. This is deliberately not implemented using Java Reflection API, but by a more direct interfacing to get highest ...