文档介绍：J2EE and Java Application Server —— A Practitioner ’s Perspective
Ruan Tong, Wei Jun and Li Jing
Institute of Software, Chinese Academy of Science
2. The ambiguous role of EJB and Server-Side
Web Application Server JavaBeans
At the first glance, business logic and presentation
Application servers today begin to incorporate
logic resides in server-side JavaBeans and JSP pages
features and services of both web page servers and
respectively, but EJB tier also contains business logic.
traditional three-tier application servers. The
Compared with ASP programmers, JSP programmers
convincing testimony is the release of EAServer
have more to choose and are more confusing about
of Sybase, bines the PowerDyamo (a
where to put business logic: Scriptlet of JSP page,
dynamic Web Page Server) and ponent
JavaBeans or EJBs? EJBs and JavaBeans are both
Transaction Server.
components model from Sun. For a long time it has
been explained that EJB is used on server-side and
Java 2 Platform, Enterprise Edition (J2EE)
JavaBeans which contains event model are used on
Most application servers today begin to support J2EE client-side. Now server-side JavaBeans emerges, and
(Java 2 platform, Enterprise Edition) from Sun, which it is not the same as the JavaBeans of the client-side,
is a series of standards designed to provide an These ponents simply expose
integ