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外文资料

所译外文资料：

① 作者： Dan Malks

② 书名： Professional JSP

③ 出版时间 : 2000.7.26

④ 所译章节 : Chapter 12

Introductory

GoodWeb applicationdesigntriestoseparate businessobjects,presentation, and manipulation of the objects into distinct layers. One benefit of using JavaServer

Pages technologyis thatitallowsus toseparate theroleof a Web designermore

clearlyfromthatofasoftwaredeveloper.Whileonasmall-scaleproject,one individual may occupy both roles, on a larger project, they are likely to be separate

and itis beneficialto separate theirworkflowsas muchas possible.Designingthe architecture for your Web application is crucial to this separation.

JSP architecture

We will examine a variety of ways to architect a system with JavaServer Pages, servlets,andJavaBeans.Wewillsee aseriesofdifferentarchitectures,eacha development of the one before. The diagram below shows this process in outline; the individual parts of the diagram will be explained in turn later in this article.

JSP architecture:

When Sun introduced Java Server Pages, some were quick to claim that servlets

hadbeen replacedas thepreferredrequesthandlingmechanisminWeb-enabled enterprisearchitectures.AlthoughJSP is a key componentof theJava 2 Platform Enterprise Edition (J2EE) specification, serving as the preferred request handler and response mechanism, we must investigate further to understand its relationship with servlets.

Othersectionsof ProfessionalJSP explainthe implementationdetailsofJSP source translation and compilation into a servlets. Understanding that JSP is built on

top of the servlet API, and uses servlet semantics, raises some interesting questions. Shouldwe no longerdevelopstand-aloneservletsinourWeb-enabledsystems? Is there some way to combine servlets and JSPs? If so, where do we place our Java code?

Arethereanyothercomponentsinvolvedintherequestprocessing,suchas JavaBeans? If so, where do they fit into the