Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and Iterative Development, Third Edition

Chapter 37. Designing a Persistence Framework with Patterns

	The most likely way for the world to be destroyed, most experts agree, is by accident. That's where we come in; we're computer professionals. We cause accidents.
	--Nathaniel Borenstein

Objectives

• Design part of a framework with the Template Method, State, and Command patterns.

• Introduce issues in object-relational (O-R) mapping.

• Implement lazy materialization with Virtual Proxies.

Introduction

The point of this chapter is not actually the design of a persistence framework, but, more generally, to introduce key OO framework design principles and patterns, using persistence as an interesting case study.

The NextGen application—like most—requires storing and retrieving information in a persistent ...