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= 1 \* GB3 ① 作者：Dan Malks

= 2 \* GB3 ② 书名：Professional JSP

= 3 \* GB3 ③ 出版时间: 2000.7.26

= 4 \* GB3 ④ 所译章节: Chapter 12

12.1 Introductory

Good Web application design tries to separate business objects, presentation, and manipulation of the objects into distinct layers. One benefit of using JavaServer Pages technology is that it allows us to separate the role of a Web designer more clearly from that of a software developer. While on a small-scale project, one individual may occupy both roles, on a larger project, they are likely to be separate and it is beneficial to separate their workflows as much as possible. Designing the architecture for your Web application is crucial to this separation.

12.2 JSP architecture

We will examine a variety of ways to architect a system with JavaServer Pages, servlets, and JavaBeans. We will see a series of different architectures, each a 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 had been replaced as the preferred request handling mechanism in Web-enabled enterprise architectures. Although JSP is a key component of the Java 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.

Other sections of Professional JSP explain the implementation details of JSP 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. Should we no longer develop stand-alone servlets in our Web-enabled systems? Is there some way to combine servlets and JSPs? If so, where do we place our Java code? Are there any other components involved in the request process