Java™ Data Objects

1.1. What is object persistence?

In Java (and other object oriented programming languages) an object is an instance of a class. As such it has state (its attribute values) and behavior (its methods). The collection of all class definitions that comprise an application is known as the application’s object model. These classes perform a variety of functions: some render user interfaces; some manage system resources; some represent application events. However, within each object model there is usually a distinct set of objects that are direct abstractions of business concepts – typically with names to which non-technical business people would ascribe meaning. In an order processing application these may be “Customer,” “Order,” and “Product.” For ...