jsp在线考试系统-bean文件

　2000-12-11 16:37:56　来源：WEB开发网　　　

核心提示：一个在线考试系统，测试你的jsp知识，jsp在线考试系统-bean文件，代码不是特别多，所以不加注释了(http://jspbbs.yeah.net)QuizResponses.javaanswer.jsp<%-- Include directive --%><%@ include file=&quo

一个在线考试系统，测试你的jsp知识，代码不是特别多，所以不加注释了(http://jspbbs.yeah.net)
QuizResponses.java

answer.jsp

<%-- Include directive --%>
<%@ include file="header.html" %>

<TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0">
<TR>
<TD VALIGN="TOP">
<DIV ALIGN="RIGHT">
<A HREF="/developer/Quizzes/index.html">Quizzes
Index</A></DIV>
<H2 ALIGN="RIGHT">JSP PRofessional, Chapter 12 Quiz
Answers</H2>
<H4 ALIGN="RIGHT">by Dan Malks</H4>
 
<TABLE BORDER="0" CELLSPACING="8" CELLPADDING="2" <TR><TD>


<%-- Page directive that applies to entire page. --%>
<%@ page language="java" %>

<%-- Identifies bean as "worker" and tells the page where to locate the bean. --%>
<jsp:useBean id="worker" class="jdc.quiz.QuizResponses" scope="request" />

<%-- Set bean properties with a wildcard. --%>
<jsp:setProperty name="worker" property="*" />

<%-- Scoring --%>

<%-- Variable declaration in code scriptlet -->
<% int score = 0; %>





<TR><TD VALIGN="TOP">1.</TD>

<%-- 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 ++; %>

<TD VALIGN="TOP"> D
is correct!</TD>

<% } else if (worker.getOne() != null) { %>

<TD VALIGN="TOP"><jsp:getProperty name="worker" property="one" />
is incorrect!</TD>

<% } else { %>

<TD VALIGN="TOP">Blank X</TD>

<% } %>

<TD VALIGN="TOP">
Every JavaServer PagesTM
(JSP)TMsource page is compiled into
a servlet before it is executed at runtime.</A> </TD></TR>



<TR><TD VALIGN="TOP">2.</TD>

<% if ((worker.getTwo() != null) && ((worker.getTwo()).equals("B"))) { score ++; %>

<TD VALIGN="TOP"> B
is correct! </TD>

<% } else if (worker.getTwo() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="two" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank
X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">3.</TD>

<% if ((worker.getThree() != null) && ((worker.getThree()).equals("D"))) { score ++; %>

<TD VALIGN="TOP"> D
is correct! </TD>

<% } else if (worker.getThree() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="three" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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 <CODE>RequestDispatcher</CODE>. 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.

</TD></TR>



<TR><TD VALIGN="TOP">4.</TD>

<% if ((worker.getFour() != null) && ((worker.getFour()).equals("C"))) { score ++; %>

<TD VALIGN="TOP"> C
is correct! </TD>

<% } else if (worker.getFour() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="four" /> is
incorrect</TD>

<% } else { %>

<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">5.</TD>

<% if ((worker.getFive() != null) && ((worker.getFive()).equals("A"))) { score ++; %>

<TD VALIGN="TOP"> 
A is correct! </TD>

<% } else if (worker.getFive() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="five" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">6.</TD>

<% if ((worker.getSix() != null) && ((worker.getSix()).equals("B"))) { score ++; %>

<TD VALIGN="TOP"> 
B is correct! </TD>

<% } else if (worker.getSix() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="six" /> is
incorrect</TD>

<% } else { %>

<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">7.</TD>

<% if ((worker.getSeven() != null) && ((worker.getSeven()).equals("B"))) { score ++; %>

<TD VALIGN="TOP">
B is correct! </TD>

<% } else if (worker.getSeven() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="seven" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">8.
</TD>

<% if ((worker.getEight() != null) && ((worker.getEight()).equals("A"))) { score ++; %>

<TD VALIGN="TOP">
A is correct! </TD>

<% } else if (worker.getEight() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="eight" /> is
incorrect</TD>

<% } else { %>
<TD>Blank
X</TD>

<% } %>

<TD VALIGN="TOP">
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:

<IMG SRC=http://www.cncms.com/"Image1.gif" WIDTH="412" HEIGHT="204" ALT="JSP Page-Centric">

</TD></TR>



<TR><TD VALIGN="TOP">9.
</TD>

<% if ((worker.getNine() != null) && ((worker.getNine()).equals("A"))) { score ++; %>

<TD VALIGN="TOP">
A is correct! </TD>

<% } else if (worker.getNine() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="nine" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
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.

</TD></TR>



<TR><TD VALIGN="TOP">10.
</TD>

<% if ((worker.getTen() != null) && ((worker.getTen()).equals("D"))) { score ++; %>

<TD VALIGN="TOP"> D is correct! </TD>

<% } else if (worker.getTen() != null) { %>

<TD VALIGN="TOP">
<jsp:getProperty name="worker" property="ten" /> is
incorrect</TD>

<% } else { %>
<TD VALIGN="TOP">
Blank X</TD>

<% } %>

<TD VALIGN="TOP">
Error pages are invoked when there is an uncaught exception from
within a particular page. In this case, we mention that the
<CODE>validationGaurd()</CODE> method might throw an exception.
If this exception is not caught within the page, then we vector
control to the <CODE>errorPage</CODE>, as stipulated in the attribute
of the given page directive.

</TD></TR>
<%-- Scoring calculations --%>
<%
int missed = 10 - score;
double grade = (double)score/10*100;
%>

<TR><TD colspan="3">
You missed <%= missed %>
 Your score is <%= (int)grade %> percent.
<H4>Source Code</H4>
This quiz used the Page-View with Bean Approach, detailed in <A
HREF="/developer/Books/javaserverpages/">Chapter 12, JSP Archeticure</A>. The <A HREF="index.txt">first
page</A> of the quiz consists of regular HTML with a form that calls <A
HREF="answer.txt"><CODE>answer.jsp</CODE></A>. <CODE>Answer.jsp</CODE> requests parameters from the bean,
in this case, called <A HREF="QuizResponses.txt">QuizResponses</A>. The page-view with bean
approach for this quiz required extra work to write the bean, and it could have been done using the
page-view approach without a bean, requesting invocation directly from the <CODE>answer.jsp</CODE>
page. Deciding which approach is preferrable depends on the application and how much HTML and Java
scriptlets need to be used. For this quiz we opted for the page-view with bean approach for
illustration purposes.

<A HREF=/developer/Quizzes/jsp/index.html>Back to Quiz</A>
<IMG SRC=http://www.cncms.com/images/T7.gif ALIGN=LEFT>

</TABLE>


<%@ include file="footer.html" %>