1) A software company wants to develop a component that does many of the pre-processing stuffs like whether the requests are coming from authentic sources, filtering unwanted data in the request object. What type of pattern will be the best match for developing such a component?

1. Front Controller
2. Business Controller
3. Business Delegate
4. Intercepting Filter

2) A class wants to keep track of its number of objects being added to HttpSession objects. Which will be the ideal way to achieve this?

1. Define a listener class implementing HttpSessionListener and whenever an object is added to Http Session object, keep track of the number of instances.
2. Define a listener class implementing HttpSessionBindingListener and in the valueBound() method, keep track of the number of instances being added in a static variable.
3. It is highly impossible to keep track the number of objects being added to a Http Session in a Web Application.
4. The Servlet API provides direct support for keeping track the object instances.

3) What will be the output of the following JSP code snippet at run-time when it is accessed the third time?

<% int test = 0; %>
<% ++test; %>
The value of test is 
<%= test %>

1. The value of the 'test' variable will be 2.
2. The value of the 'test' variable will be 0.
3. The value of the 'test' variable will be 1.
4. The variable 'test' must be declared at global scope, else a run-time error will occur.

4) What method can be used to retrieve all the parameter names being sent as part of the request by the client?

1. Use the method 'HttpServletRequest.getParameterNames()' which will return an enumeration of parameter names.
2. Use the method 'HttpServletResponse.getParameterNames()' which will return an enumeration of parameter names.
3. Use the method 'HttpServletRequest.getAllParameters()' which will return an enumeration of parameter names.
4. There is no direct support in the Servlet API to retrieve the name of all the parameters sent by the client.

5) Given the deployment descriptor for a Web Application is

<web-app version="2.4">
	
    <servlet>
        <servlet-name>InitParamsServlet</servlet-name>
        <servlet-class>scwcd14.chap02.InitParamsServlet</servlet-class>
    </servlet>


    <servlet-mapping>
        <servlet-name>InitParamsServlet</servlet-name>
        <url-pattern>/InitParamsServlet</url-pattern>
        
        <init-param>
            <param-name>name</param-name>
            <param-value>javabeat</param-value>
        </init-param>

    </servlet-mapping>

</web-app>

What will be the output of the following Servlet?

package scwcd14.chap02;

import java.io.*;
import java.net.*;

import javax.servlet.*;
import javax.servlet.http.*;

public class InitParamsServlet extends HttpServlet {
    
    public void init(){
        
        ServletConfig config = getServletConfig();
        System.out.println(config.getInitParameter("name"));
        System.out.println(config.getInitParameter("no-name"));
    }  
    ...
}

1. The Servlet will output 'javabeat null' in the Server Console.
2. The Servlet will fail to load as the init param property 'no-name' is not mentioned in the deployment descriptor.
3. A NullPointerException will be raised as calling getServletConfig() in the init() method will return a null reference.

6) Following is an excerpt taken from a Deployment Descriptor of some Web Application.

<web-app version="2.4">
    
    <context-param>
        <param-name>app-name</param-name>
        <param-value>MockQuestions</param-value>
    </context-param>

   <servlet>
        <servlet-name>ContextInfoServlet</servlet-name>
        <servlet-class>scwcd14.chap03.ContextInfoServlet</servlet-class>
        
        <init-param>
            <param-name>app-name</param-name>
            <param-value>ContextInfoServlet</param-value>
        </init-param>
    </servlet>

</web-app>

7)Which of the following code will output the message 'MockQuestions ContextInfoServlet' to the client browser (assuming that 'out' is a valid instance of type 'PrintWriter' class)?

out.println(config.getServletContext().getParameter("app-name"));
out.println(config.getInitParameter("app-name"));


out.println(config.getInitParameter("app-name"));
out.println(config.getServletContext().getInitParameter("app-name"));


out.println(config.getServletContext().getInitParameter("app-name"));
out.println(config.getInitParameter("app-name"));


out.println(config.getServletContext().getInitParameter("app-name"));
out.println(config.getParameter("app-name"));

7) Which of the following tag library definition is valid?

<tag>
<name>hello</name>
<tag-class>test.HelloTag</tag-class >
</tag>
<tag>
<name>anotherHello</name>
<tag-class>test.AnotherHelloTag</tag-class>
</tag>


<tag>
<name>hello</name>
<tag-class>test.HelloTag</tag-class >
</tag>
<tag>
<name>hello</name>
<tag-class> test.HelloTag</tag-class>
</tag>


<tag>
<name>root</name>
<tag-class>test.RootTag</tag-class >
<sub-tag>
<name>child</name>
<tag-class>test.ChildTag</tag-class>
	</sub-tag>
</tag>

8) What is the equivalent action code for the following piece of JSP code snippet?

EmployeeBean harry = (EmployeeBean)request.getAttribute("harry");
if (harry == null)
{
harry = new EmployeeBean();
request.setAttribute("harry", harry);
}

1. <jsp:declareBean id = "harry" class = "EmployeeBean" scope = "request" />
2. <jsp:createBean id = "harry" class = "EmployeeBean" />
3. <jsp:useBean id = "harry" class = "EmployeeBean" scope = "request" />
4. <jsp:useBean id = "harry" class = "EmployeeBean" />

9) Which of the following is a valid declaration of a Tag Library in a Deployment Descriptor?

<taglib>
<uri>http://www.javabeat.net/studyKit</uri>
<location>/studyKit.tld</location>
</taglib>



<taglib>
<uri>http://www.javabeat.net/studyKit<uri>
<location>/studyKit.tld</location>
</taglib>


<taglib>
<taglib-uri>http://www.javabeat.net/studyKit</taglib-uri>
<taglib-location>/studyKit.tld</taglib-location>
</taglib>


<taglib>
<uri>http://www.javabeat.net/studyKit</uri>
<path>/studyKit.tld</path>
</taglib>

10) Which of the following EL expression retrieves the value of the attribute by name 'attribute' found in HTTP's request object

1. ${request.getAttribute()}
2. ${request.attribute}
3. ${pageContext.request.getAttribute()}
4. ${pageContext.request.attribute}

Answers

1) d.

2) b.

3) c.

4) a.

5) a.

6) c.

7) a.

8) c.

9) c.

10) d.