【正文】 are able to use the Java Reflection API to discover a JavaBean’s properties by looking for methods prefixed by set, is, or get. If a ponent finds such a signature on a JavaBean, it knows that the method can be used to access or change the bean’s properties. Sun introduced JavaBeans to work with GUI ponents, but they are now used with every aspect of Java development, including web applications. When Sun engineers developed the JSP tag extension classes, they designed them to work with JavaBeans. The dynamic data for a page can be passed as a JavaBean, and the JSP tag can then use the bean’s properties to customize the output. For more on JavaBeans, we highly remend The Awesome Power of JavaBeans, by Lawrence H. Rodrigues [Rodrigues]. The definitive source for JavaBean information is the JavaBean Specification [Sun, JBS]. Model 2: The release of the Servlet/JSP Specification described Model 2 as an architecture that uses servlets and JSP pages together in the same application. The term Model 2 disappeared from later releases, but it remains in popular use among Java web developers. Under Model 2, servlets handle the data access and navigational flow, while JSP pages handle the presentation. Model 2 lets Java engineers and HTML developers each work on their own part of the application. A change in one part of a Model 2 application does not mandate a change to another part of the application. HTML developers can often change the look and feel of an application without changing how the backoffice servlets work. The Struts framework is based on the Model 2 architecture. It provides a controller servlet to handle the navigational flow and special classes to help with the data access. A substantial custom tag library is bundled with the framework to make Struts easy to use 9 with JSP pages. Summary: In this article, we introduced Struts as an application framework. We examined the technology behind HTTP, the Common Gateway Interface, Java servlets, JSPs, and JavaBeans. We also looked at the Model 2 application architecture to see how it is used to bine servlets and JSPs in the same application. Now that you have had a taste of what it is like to develop a web application with Struts, in chapter 2 we dig deeper into the theory and practice behind the Struts architecture. xxx大學(xué)畢業(yè)設(shè)計（論文）外文翻譯 —— 譯文 1 JSP 應(yīng)用框架 什么是應(yīng)用框架： 框架（ framework）是可重用的，半成品的應(yīng)用程序，可以用來產(chǎn)生專門的定制程序。 is all too mon in servlets that generate the HTTP response. There are libraries that can help you generate HTML, but as applications grow more plex, Java developers end up being cast into the role of HTML page designers. Meanwhile, given the choice, most project managers prefer to divide development teams into specialized groups. They like HTML designers to be working on the presentation while Java engineers sweat the business logic. Using servlets alone encourages mixing markup with business logic, making it difficult for team members to specialize. To solve this problem, Sun turned to the idea of using server pages to bine scripting and templating technologies into a single ponent. To build Java Server Pages, developers start by creating HTML pages in the same old way, using the same old HTML syntax. To bring dynamic content into the page, the developer can also place JSP scripting elements on the page. Scripting elements are tags that encapsulate logic that is recognized by the JSP. You can easily pick out scripting elements on JSP pages by looking for code that begins with % and ends with %. To be seen as a JSP page, the file just needs to be saved with an extension of .jsp. When a client requests the JSP page, the container translates the page into a source code file for a Java servlet and piles the source into a Java class file— just as you would do if you were writing a servlet from scratch. At runtime, the container can also check the last modified date of the JSP file against the class file. If the JSP file has changed since it was last piled, the container will retranslate and rebuild the page all over again. Project managers can now assign the presentation layer to HTML developers, who then pass on their work to Java developers to plete the businesslogic portion. The important thing to remember is that a JSP page is really just a servlet. Anything you can do with a servlet, you can do with a JSP. 7 JavaBeans: JavaBeans are Java classes which conform to a set of design patterns that make them easier to use with development tools and other ponents. DEFINITION A JavaBean is a reusable software ponent written in Java. To qualify as a JavaBean, the class must be concrete and public, and have a noargument constructor. JavaBeans expose internal fields as properties by providing public methods that follow a consistent design pattern. Knowing that the property names follow this pattern, other Java classes are able to use introspection to discover and manipulate JavaBean p