动态分类的UML表示方法

The Ways of Expressing Dynamic Classification by Using UML

动态分类是指对象所属的类可随时间而变化。在进行系统分析和软件开发中，需要真实地描述研究对象在其生命周期中的变化，动态分类正是这样一种机制。但是由于许多面向对象程序设计语言都不支持动态分类，因此需要用别的方法来描述动态分类，文中给出了用ＵＭＬ表达动态分类的四种机制，并对这四种机制进行了比较。

Dynamic classification means that the classification of object can change over time.It is necessary for us to describe the transformation of the objects during their life cycle when we analysis system and develop software.Dynarnic classification does satisfy the need.But many object-oriented programming language do not support it,so need other ways to express it.Four mechanisms of UML are presented in this paper.They are stereotype, multipe interface,delegation and programming.At last,the paper compares them.