针对应用系统ER模型的MDA模型转换方法

MDA是由OMG提出的一种以模型为主要开发产品的软件开发方法。开发人员首先建立与具体技术平台的实现细节无关的高抽象程度的平台无关模型（Platform Independent Model，PIM）。然后，开发人员可以通过模型转换，将高层次的模型逐渐转换成为包含了实现细节的平台相关模型（Platform Specific Model，PSM），直到最终的代码。模型转换的有效性决定了MDA开发方法的效率。模型转换的难点不在于模型的语法映射，而是保证转换过程中模型语义的一致。本文采用E1）C）C作为平台无关模型的描述方法。EDOC是OMG制定的、和具体应用平台无关的、适用于企业分布式系统建模的标准。本文针对EDOC中的实体关系模型建立了从这些模型到J2EE平台模型以及目标代码的模型转换规则。我们还在转换规则中引入了多个设计模式。软件开发人员可以根据对软件的非功能性需求，应用这些规则来选择不同的设计模式，将平台无关的ER模型转换成为J2EE平台上的模型。

MDA Model Transformation Methods for EDOC ER Models

The Model Driven Architecture(MDA)proposed by OMG uses software models as the primary artifacts of software development.In MDA,application system models are first constructed independently of specific platforms and implementation technologies.These high abstract models can be automatically mapped into low-level models or declarative codes by model transformation technologies.The efficacy of Model Driven Architecture is mainly determined by the efficacy of model transformation tools.The main difficult problem of model transformation is to maintain semantic consistency between models of different abstract levels during transformation.We use the EDOC profile,a platform-independent standard adopted by OMG,to describe PIMs.This standard is designed for modeling distributed enterprise applications.In this paper,we focus on the problem of how to define transformation rules from EDOC entity and relationship models to concrete implementations on J2EE platform.Several design patterns are introduced into model transformation rules in order to improve transformation efficacy.Using these transformation rules,platform-independent models(PIMs)can be transformed to J2EE platform dependent models(PSMs)automatically.