UML中如何描述系统的体系结构(二)


The
use case view of a system encompasses the use cases that describe the behavior of the system as
seen by its end users, analysts, and testers. This view doesn’t really specify the organization
of a software system. Rather, it exists to specify the forces that shape the system’s architecture.
With the UML, the static aspects of this view are captured in use case diagrams; the dynamic aspects of this view are captured in interaction diagrams, state diagrams, and activity diagrams.
The
design view
of a system encompasses the classes, interfaces, and collaborations that form the vocabulary of the problem and its solution. This view primarily supports the functional requirements
of the system, meaning the services that the system should provide to its end users. With the UML, the static aspects of this view are captured in class diagrams and object diagrams; the dynamic aspects of this view are captured in interaction diagrams, state
diagrams, and activity diagrams. The internal structure diagram of a class is particularly useful.
The
interaction view
of a system shows the flow of control among its various parts, including possible concurrency and synchronization mechanisms. This view primarily addresses the performance,
scalability, and throughput of the system. With the UML, the static and dynamic aspects of this view are captured in the same kinds of diagrams as for the design view, but with a focus on the active classes that control the system and the messages that flow
between them.

系统的用例视图包含的用例，作用是以终端用户，分析人员和测试人员的视角来描述系统的行为．这个视图不能真正的描述软件系统的组织．相反地，它的作用是体现系统的体系结构．在UML中，用例图捕获的是该视图的静态一面;动态一面则是通过交互图，状态图和活动图捕获．
系统的设计视图包含类，接口和协作，以便形成问题词汇表和解决问题的方案．这类视图主要支持系统的功能需求，也就是这个系统提供给终端用户的服务．在UML中，类图和对象图捕获的是该视图的静态一面；动态一面则由交互图，状态图和活动图捕获．类的内部结构图特别有用．
系统的交互视图显示不同部件之间的控制流，包含可能的并发和同步机制．这类视图主要定位执行性，扩展性和系统吞吐量．在UML中，捕获该视图的静态属性和动态属性与设计视图一致，但它更注重那些控制系统的活动类及在这些活动类之间流转的消息．