第三章 模型驱动开发概述.ppt

* * Rational uses the concept of Model-Driven Development to describe its entire tool-supported, model-centric approach to software development. MDD describes an array of ways to apply models to software development, including Model-Driven Architecture. The Model-Driven Architecture (MDA) is an approach to software development in which models drive every stage of the design and development of an application. Model transformation, using a tool to transform one model into another based on a standard scheme (a transformation definition), makes Model-Driven Architecture possible. An abstract, platform-independent model that describes a solution that can be reused in many contexts, can be transformed into potentially multiple platform-dependent models. Transformation definitions can be standardized to help automate implementation and make the executable code more consistent across the application. MDA is not to be confused with Model-Driven Development (MDD), also known as Model-Driven Software Development (MDSD). MDD is an approach to software development where extensive models are created before source code is written or generated. MDA is the OMG implementation of MDD. The MDA concept is implemented by a set of tools and standards that can be used within an MDD approach to software development. * * * * * * * * * * * To complete the class diagram, there should be a Uses relationship from Application to OpenCommand to account for the fact that the former creates the latter, and there should be another Uses relationship from Menu to Command as the AddItem operation takes one argument of type Command. * * * The following transformations are possible: Across models of the same type: When adding levels of refinement, you may transform from a PSM to another PSM. More details are added, but the type of model remains the same. Across levels of abstraction: Move from a PIM model to a PSM model as you add in details about the platform and get closer to the implementation. Fr