J2EE Design Patterns

Chapter 2. The Unified Modeling Language

Before we dive into the design patterns themselves, it’s worth stepping back and thinking about the framework they fit into. Design patterns are just one part of the much broader discipline of software engineering. Building any application involves requirements gathering, design, implementation, testing, and deployment. While design patterns provide developers with a library of proven techniques and allow teammates to apply labels to concepts, the patterns don’t begin to address every aspect of enterprise development. Most importantly, perhaps, design patterns can’t tell you where to apply a design pattern. That’s why we have design.

Design patterns describe the implementation strategies for particular areas of the application, and even the overall design. Enterprise applications in particular need effective engineering practices, given their complexity and business importance. As object-oriented languages take hold in business environments, a need has emerged for a common language to discuss and describe object-oriented software, as well as the problems and business processes the software serves.

Software and process-modeling languages were created to meet this need for common vocabulary to describe software structure. The various leading modeling languages have blended together over the last few years into the Unified Modeling Language, generally abbreviated as the UML.^[1]

UML supports all aspects of the software development life cycle, ...