The logic transaction tier of J2EE is implemented by the reusable component of EJB.In this paper,some basic concepts dealing with enterprise integrated applications such as n-tier C/S mode,J2EE and EJB are first discussed in details.

• EJB是实现J2EE架构业务逻辑层商务功能的可重用组件。 首先详细介绍了企业应用集成中的几个基本概念,如软件架构的多层C/S模式、J2EE架构、J2EE架构中的EJB组件等。