Introduction

Entity objects are the basic building blocks in the chain of business components. They represent a single row of data and they encapsulate the business model, data, rules, and persistence behavior. Usually, they map to database objects, most commonly to database tables, and views. Entity object definitions are stored in XML metadata files. These files are maintained automatically by JDeveloper and the ADF framework, and they should not be edited by hand. The default entity object implementation is provided by the ADF framework class oracle.jbo.server.EnityImpl . For large-scale projects you should create your own custom entity framework class, as demonstrated in the Setting up BC base classes recipe in Chapter 1, Pre-requisites to Success: ADF Project Setup and Foundations.

Likewise, it is not uncommon in large-scale projects to provide custom implementations for the entity object methods doDML() , create(), and remove(). The recipes in this chapter demonstrate, among other things, some of the custom functionality that can be implemented in these methods. Furthermore, other topics such as generic programming using custom properties and property sets, custom validators, entity associations, populating sequence attributes, and more, are covered throughout the chapter.