关键词: 构件, 接口, 协议, 角色, 兼容性

Abstract: Component-based software development is necessity current of software engineering and industrialization and components achieve interaction by interfaces.At present the main interface definition languages are designed initially for closure environment to satisfy the requirement of C/S application，and only describe static syntax level information of component interaction which can not meet the need of understand，usage and deduce of component in open environment.Formal description methods are being got more and more attention because of their accuracy and the use of automated theorem proving mechanism.This paper proposes the extension approach to component interfaces including dynamic behavior information based on π calculus，then divides roles according to the role component acts in the system and researches the compatibility of component composition based on roles division to ensure the correctness of composition and interaction in open environment.To illustrate what the paper presents，an electronic commerce application system is used as an example.

Key words: component, interface, protocol, role, compatibility