【正文】 s scripting feature is being on and malicious users can easily work around clientside validation. 畢業(yè)設(shè)計(jì)（論文） 外文文獻(xiàn)翻譯 14 ? Model Objects. Model objects in Javabased Web applications are in the forms of JavaBeans. Model objects make up the Model part of the MVC based design model. A model object can be used to bind a ponent value to be used at a later stage. In addition, it can encapsulate business logic required for processing. ? Page Navigation. Almost all Web applications have multiple pages that the user can navigate from one to another. All MVCbased design models use a servlet as the Controller part. This servlet also acts as the sole entry point to the application. Which page to be displayed after the current request is determined by the value of a specified request parameter. Managing page navigation is critically important. 3. Web Application Design Models The Model 2 design model is based on the ModelViewController (MVC) design pattern. As explained by Burbeck [1], there are three main modules in MVC, the Controller, the View, and the Model. The Controller acts as the central entry point to the application. All user interactions go through this controller. The View contains the presentation part of the application, and the Model stores data or encapsulates business logic of the application. In the later development, the Struts Framework provides a mon framework to easily build Model 2 applications. Then, the last initiative is the JavaServer Faces, which also employs the MVC design pattern. In the following sections, we discuss these three design models and explain how each design model addresses the development issues specified in the previous section. Model 2 A Java Web application that is based on the Model 2 design model has one servlet (called the Controller servlet) that serves as the Controller part. All requests are first handled by this servlet, which immediately dispatches the requests to the appropriate views using RequestDispatcher objects. Views in the Model 2 design model are represented by JSP pages. To store data, a Model 2 application uses JavaBeans, which are the Model part of the application. In addition to storing data, the JavaBeans also encapsulate business logic. Each HTTP request carries an action parameter that indicates 畢業(yè)設(shè)計(jì)（論文） 外文文獻(xiàn)翻譯 15 which view to dispatch this request to. The programmer must code the HTML tags for user interface in all JSP pages in the application and write input validation code. In addition, the model objects are managed by individual JSP pages. Struts The Struts Framework is an improvement of the Model 2 design model. It provides a default Controller servlet so that the user does not have to write and pile one. Struts alleviates the task of page navigation by allowing navigation rules to be present in its application configuration file (an XML document). Changes to the navigation rules do not require repilation of a Java servlet class. In addition to easier page navigation, Struts provides custom tag libraries that define tags representing HTML elements. One of these tags is used for error handling and Struts is therefore capable of displaying localized error messages in support for internationalization. Struts applications use JavaBeans as their models, just like the Model 2 design model. In addition, Struts programmers have to write their own input validation code. JSF JSF also employs a controller servlet that is called FacesServlet. This servlet is the only entry point to a JSF application. JSF also uses JSP pages as its views and JavaBeans as its model objects. Unlike Model 2 and Struts, however, JSF provides readytouse user interface ponents that can be written on JSP pages. Upon an invocation of a page of a JSF application, the FacesServlet constructs a ponent tree that represents the JSP page being requested. Some of the ponents can also trigger events, making JSF eventdriven. For page navigation, JSF uses an approach similar to Struts, ., by allowing navigation rules to be defined in an application configuration file (again, an XML document). What distinguishes a JSF application from nonJSF servlet/JSP application is that JSF applications are eventdriven. The user interface of a JSF application is one or many JSP pages that host Web ponents such as forms and input boxes. These ponents are represented by JSF custom tags and can hold data. A ponent can be nested inside another, and it is possible to draw a tree of ponents. Just as in normal servlet/JSP 畢業(yè)設(shè)計(jì)（論文） 外文文獻(xiàn)翻譯 16 applications, you use JavaBeans to store the data the user entered. 4. Experimental Setup The software and hardware details for our experiments are described below. The Online Store Application The online store application in this research es in three versions: Model 2, Struts, and JSF. All of them are named BuyDirect, an online store that sells electronics goods. The application has the following features: Search for certain products based on product names or descriptions. Browse the list of products by category. View a product39。 Struts is a framework employing the Model 2 design model。 畢業(yè)設(shè)計(jì)（論文） 外文文獻(xiàn)翻譯 10 參考文獻(xiàn) 1. Burbeck, S., Applications Programming in Smalltalk80: How to use ModelView Controller (MVC), 1987. 2. Cecchet, E., Chanda A., Elnikety S., Marguerite J., Zwaenepoel W.: Performance Comparison of Middleware Architectures for Generating Dynamic Web Content. Proceeding of the 4th International Middelware Conference, 2020. 3. Cecchet, E., Marguerite, J., and Zwaenepoel, W.: