时间：2021-07-01 10:21:17 帮助过：2人阅读
Quizzes Index JSP Professional, Chapter 12 Quiz | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
<%-- Page directive that applies to entire page. --%> <%@ page language="java" %> <%-- Identifies bean as "worker" and tells the page where to locate the bean. --%> <%-- Set bean properties with a wildcard. --%> <%-- Scoring --%> <%-- Variable declaration in code scriptlet --> <% int score = 0; %> 1. | <%-- The method getOne() was set up in the bean with the id "worker" --%> <%-- All Java code is enclosed in <% %>, leaving HTML to be easily --%> <%-- changed or updated. --%> <% if((worker.getOne() != null) && ((worker.getOne()).equals("D"))) { score ++; %> D | is correct! <% } else if (worker.getOne() != null) { %> is incorrect! <% } else { %> Blank X | <% } %> | Every JavaServer PagesTM (JSP)TMsource page is compiled into a servlet before it is executed at runtime. 2. | <% if ((worker.getTwo() != null) && ((worker.getTwo()).equals("B"))) { score ++; %> B | is correct! <% } else if (worker.getTwo() != null) { %> incorrect <% } else { %> Blank X <% } %> | When large amounts of Java scriptlet code are mixed with HTML markup within a JSP page, not only do readability and reuse suffer, but often bugs are introduced as web-production team members, who may not be familiar with Java programming, need to modify the accompanying markup. Additionally, dependencies now exist among various teams competing for the same file, making the development process less efficient. 3. | <% if ((worker.getThree() != null) && ((worker.getThree()).equals("D"))) { score ++; %> D | is correct! <% } else if (worker.getThree() != null) { %> incorrect <% } else { %> Blank X <% } %> | Doing an HTTP redirect requires a round-trip to the client. If this is not required, and the only desire is to forward the request to another resource, then this can be much more efficiently accomplished with the RequestDispatcher. Additionally, when using the dispatcher the state of the request object is maintained between resources, which will not be the case with the HTTP redirect. 4. | <% if ((worker.getFour() != null) && ((worker.getFour()).equals("C"))) { score ++; %> C | is correct! <% } else if (worker.getFour() != null) { %> incorrect <% } else { %> Blank X <% } %> Business logic is better contained in a JavaBeanTM or a servlet, which is owned by a software developer. When lots of Java code is embedded directly within the JSP page as scriptlets, the "cut-and-paste" mentality tends to prevail when it comes to code reuse. 5. | <% if ((worker.getFive() != null) && ((worker.getFive()).equals("A"))) { score ++; %> | A is correct! <% } else if (worker.getFive() != null) { %> incorrect <% } else { %> Blank X <% } %> | Since the servlet is the initial contact point for each request, it is well-suited to handle logic that is common across multiple requests. A good example of this type of logic is an authentication check. 6. | <% if ((worker.getSix() != null) && ((worker.getSix()).equals("B"))) { score ++; %> | B is correct! <% } else if (worker.getSix() != null) { %> incorrect <% } else { %> Blank X <% } %> | Using a business delegate reduces coupling between the presentation and business tiers. The presentation tier has no knowledge of the EJB implementation details, such as Java Naming and Directory InterfaceTM lookup. 7. | <% if ((worker.getSeven() != null) && ((worker.getSeven()).equals("B"))) { score ++; %> | B is correct! <% } else if (worker.getSeven() != null) { %> incorrect <% } else { %> Blank X <% } %> | Using Java scriptlets is the accepted method of doing iteration in JSPTM 1.0. In JSPTM 1.1, a custom tag may be used, which will hide the implementation details of the iteration code. 8. | <% if ((worker.getEight() != null) && ((worker.getEight()).equals("A"))) { score ++; %> | A is correct! <% } else if (worker.getEight() != null) { %> incorrect <% } else { %> Blank | X <% } %> | The term Page-Centric is used to describe an architecture where the initial contact point for the request is a JSP page. An example is shown visually below:
9. | <% if ((worker.getNine() != null) && ((worker.getNine()).equals("A"))) { score ++; %> | A is correct! <% } else if (worker.getNine() != null) { %> incorrect <% } else { %> Blank X <% } %> | When the forward method is used, the invoking resource does not regain control. Multiple include invocations can be made from the same resource, while the invoking resource maintains execution control. 10. | <% if ((worker.getTen() != null) && ((worker.getTen()).equals("D"))) { score ++; %> D is correct! | <% } else if (worker.getTen() != null) { %> incorrect <% } else { %> Blank X <% } %> Error pages are invoked when there is an uncaught exception from within a particular page. In this case, we mention that the validationGaurd() method might throw an exception. If this exception is not caught within the page, then we vector control to the errorPage, as stipulated in the attribute of the given page directive. <%-- Scoring calculations --%> <% int missed = 10 - score; double grade = (double)score/10*100; %> | You missed <%= missed %> Source CodeThis quiz used the Page-View with Bean Approach, detailed in HREF="/developer/Books/javaserverpages/">Chapter 12, JSP Archeticure. The first Back to Quiz
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