Web App midterm

Question 1

processing requests

Accepted Answer

y

Question 2

[blank_start]Servlet + JSP[blank_end]
Lower-level API that does less work for the programmer.
Provides a high degree of control over the HTML/CSS/JavaScript that’s returned to the browser.
The necessary background for understanding higher-level APIs.

[blank_start]JSF[blank_end]
Higher-level API that does more work for the programmer.
Makes it more difficult to control the HTML/CSS/JavaScript that’s returned to the browser.

[blank_start]Spring Framework[blank_end]
Higher-level API that does more work for the programmer.
Provides a high degree of control over the HTML/CSS/JavaScript that’s returned to the browser. 
Great choice for large and small web applications.

Accepted Answer

Servlet + JSP

Accepted Answer

JSF

Accepted Answer

Spring Framework

Question 3

[blank_start]The Java Standard Edition ( Java SE )[blank_end] includes the Java Development Kit (JDK) and the Java Runtime Environment (JRE).

[blank_start]The Java Enterprise Edition ( Java EE )[blank_end]specification describes how web servers can interact with all Java web technologies.

[blank_start]Servlets[blank_end] store the Java code that does the server-side processing.

[blank_start]JavaServer Pages ( JSP )[blank_end] store the HTML and dynamically defines the user interface.

[blank_start]JavaServer Faces ( JSF )[blank_end] is a higher-level API that can be used instead of both servlets and JSPs.

[blank_start]Java Persistence API ( JPA )[blank_end] is a powerful and convenient API for working with databases

Accepted Answer

The Java Standard Edition ( Java SE )

Accepted Answer

The Java Enterprise Edition ( Java EE )

Accepted Answer

Servlets

Accepted Answer

JavaServer Pages ( JSP )

Accepted Answer

JavaServer Faces ( JSF )

Accepted Answer

Java Persistence API ( JPA )

Question 4

Two popular web servers:
Tomcat:
servlet/jsp engine includes web server

glassfish:
complete java ee application server

Answer

true

Question 5

JSP Expressions start with <%= and end with %>. May contain any Java expression 2 + 2 = <% 2 + 2 %> <% java for loop %>

Answer

true

Question 6

JSP Comments start with <%-- and end with --%>

difference with html comment:
HTML comments are sent to browser and visible inside of the page sources.
HTML comments do not hide JSP code from the compiler.

Answer

true

Question 7

JSP Declarations start with <%! and end with %>

JSP Declarations are used to declare Java methods inside of JSP pages

Answer

true

Question 8

JSP Directives start with <%@ and end with %>.

The directives are commonly used for the following:
Defining the page content for browsers: the content type and the encoding.
Importing Java packages.
Including other files into JSP pages.
Connecting to tag files and tag libraries

<%@page import="java.util.*"%>

Answer

true

Question 9

Model 1 projects can contain:

Accepted Answer

Java Server Pages

Accepted Answer

HTML pages

Accepted Answer

Style Sheets

Accepted Answer

Images

Accepted Answer

Custom Tags

Accepted Answer

JavaBeans

Accepted Answer

Configuration Files

Accepted Answer

Data Access Code

Answer

SQL files

Answer

Librarys

Question 10

JavaBeans are Java public classes that satisfy the following three requirements:
1.Implement Serializable (or Externalizable) interface.
2.Provide public no-argument constructor.
3.Provide all necessary public get/set methods.

Answer

true

Question 11

<jsp:useBean id="card" class="Card"/>

jsp:useBean tag instantiates the bean using its no-argument constructor if the instance does not exist
default scope is only this page
is NOT used in model 2 projects

Answer

true

Question 12

JavaBean classes must use get/set methods for variables

Answer

true

Question 13

${card.number}

the above uses useBean tag and id to be able to call class and its methods it is possible to call set methods within JSP

Answer

true

Question 14

1.2.3.4.5.6.7.8.9.

Accepted Answer

Servlet as controller/dispatcher

Accepted Answer

JSPs as Views

Accepted Answer

HTML pages as Views

Accepted Answer

Style Sheets

Accepted Answer

Images

Accepted Answer

Custom Tags

Accepted Answer

JavaBeans as Model

Accepted Answer

Configuration Files

Accepted Answer

Data Access Code

Answer

SQL Files

Question 15

Servlets are Java classes that typically inherit from HttpServlet

In the NetBeans-generated project the processRequest method is called from the generated doGetand doPost methods that override the corresponding methods from the base class.

Answer

true

Question 16

HttpServletRequest and HttpServletResponse objects are provided to doGet and doPost methods as parameters

ttpServletRequestobjects contain:
IP address of the browser,
previously set cookies,
data submitted with an input form, 
browser information, 
browser language settings, etc

HttpServletResponse objects contain:
generated web-pages, 
new cookies, 
error codes, 
redirects, etc

Answer

true

Question 17

JSP is a common but not the only choice for implementing views in Model-View-Controller (MVC) design pattern

Used only as templates to display data

Since JSPs (in MVC) do not acquire data, the data should be acquired elsewhere and made available to JSPs with attributes

request.setAttribute("card", card)
The attribute names in Model 2 work just like bean ids in Model 1

Answer

true

Question 18

Servlet mapping:
url-pattern is the address (or addresses) of the servlet relative to the application folder (context path)
defines default address for web application

Answer

true

Question 19

Forwarding:
happens entirely on server side
browsers not involved
Browsers obtain the pages, printed by JSPs, as the pages come directly from the servlet.
Request attributes are retained in forwarding: the request object, with its attributes, is passed to the JSP

Answer

true

Question 20

Three ways to may a Servlet
1.Using @WebServlet annotation in the corresponding Servlet Java file
2.Using XML: <servlet> and <servlet-mapping> tags in web.xml file
3.Configuring dynamically (programmatically), using API calls in Java code

do NOT use more than 1 method for same application

Answer

true

Question 21

@WebServlet annotation:

@WebServlet (urlPatterns= {"/input", "/process"})

Answer

true

Question 22

The Default Servlet has the Servlet name “default”.

In mapping patterns, “/” means all addresses of the application, not only the default address of the application, but all of them.

If another Servlet is mapped to “/”, the CSS and image files will not be available, unless image and CSS folders are remapped explicitly later

Answer

true

Question 23

[blank_start]Model[blank_end]:
Encapsulates core data and logic
Independent from views
can be implemented with JavaBeans and other classes

[blank_start]Views[blank_end]
Present the outputs to the user
Associated with a controller
Can be implemented with JSPs and other options

[blank_start]Controller[blank_end]
Receives inputs from the user
Processes the inputs translating them to model API
Connects model data to views and dispatches the views
Can be implemented with servlets or filters

Accepted Answer

Model

Accepted Answer

Views

Accepted Answer

Controller

Question 24

Controller vs Dispatcher:
The servlet (or filter) is often combined with an additional helper class, containing methods called from the servlet.

Dispatcher code is usually reuseable between programs
Spring dispatcher is a servlet

Answer

true

Question 25

String g = getInitParameter("greet");
request.setAttribute("greet", g);

Servlet initialization parameters are defined for specific servlets and available only inside of the servlets

Servlet initialization parameters are NOT global

Answer

true

Question 26

Form Action:

Answer

true

Question 27

HTTP GET method:
the default method to submit form data
sends form data through web address
NOT used for sensitive data
cannot be used with large data
will NOT show warnings
should NOT be used in resubmissions

Answer

true

Question 28

HTTP POST method:
not default unless specified
dose not send through web address
should be used for sensitive data
protocols should be used to to submit confidential data
can use large data
shows warnings

Answer

true

Question 29

retrieving data from form submit:
case "/InsertStudent.do":
StudentForm = new StudentForm();
form.setFirstName(request.getParameter("firstName");

Answer

true

Question 30

Input data validation:

list errors
if errors is empty
request.setAttribute("student", form);
studentData.insert(form);
view = "confirmInsert";

Answer

true

Question 31

javax.servlet jstl 1.2 All Maven projects, using JSTL, must have this JSTL dependency copy-pasted into the Project Object Model (POM) file, pom.xml. The pom.xml file is in "Project Files" folder of NetBeans projects. Almost any project that uses JSP also uses JSTL

Answer

true

Question 32

using JSTL in JSP: <%@taglib import jstl... %>

${e}

As the general rule, inserting a bean value requires ${ } The temporary variable of the c:forEach loop picks the next string from the list of strings in each iteration, starting with the first.

Answer

true

Question 33

conditions using JSTL: ..... The block inside of the c:if is excluded when the list is null or empty

Answer

true

Question 34

displaying table rows in JSTL: students from setAttribute ${s.firstName}

Answer

true

Question 35

Post Redirect Get pattern is used to avoid accidental resubmission of the data when a site visitor presses the browser reload button.

Post Redirect Get pattern involves three steps.

1.[blank_start]Post[blank_end]–The data is submitted to the server with post. The server processes the data, stores the data on the server side.

2.[blank_start]Redirect[blank_end]–The server sends a new address (redirection address) to the browser, usually, with some data id in the address.

3.[blank_start]Get[blank_end]–The browser retrieves the confirmation page, using the redirection address

Accepted Answer

Post

Accepted Answer

Redirect

Accepted Answer

Get

Question 36

Advantages of design pattern:

Accepted Answer

Improves software reusability

Accepted Answer

Faster development cycle

Accepted Answer

More readable and maintainable code

Accepted Answer

Overall efficiency of software development

Accepted Answer

Provides common vocabulary to describe problems and solutions

Answer

Less repeated code or classes

Answer

Better efficiency for delployment

Question 37

Low Coupling = Low dependency of components on each other by their lower structures, instead of their interfaces

High Cohesion= One component should perform one and only one well-defined job

Answer

true

Question 38

The Single Responsibility Principle suggests that a module should be changed for one and only one reason only. Consequently, a module should have one and only one responsibility

A change inside of a module may require a lot of further changes inside of the same module, but few (ideally, no) changes outside of this module

Answer

true

Question 39

The Open-Close Principle requires that new features are added to an existing module by extension, and not by modification

Little of a module code (ideally, no code) should be modified by adding a new feature

Answer

true

Question 40

The Liskov Substitution Principle requires that Module A can be replaced with Module B, if Module B is a subtype of Module A

Well-defined contracts (interfaces) support the definition and help reduce the coupling between modules

Answer

true

Question 41

The Interface Segregation Principle suggests that client modules should not have to deal with not used interface features

If the modules interacting with an interface are using few of the exposed functions, then the other ones should probably be moved to another interface, or even to new modules.

Avoid making interfaces that lead to a lot of empty methods in implementations
Interfaces should not have a lot of methods
Splitting an interface into two or more interfaces may improve the design

Answer

true

Question 42

Dependency inversion principle(DIP)
High-level modules should not directly depend on low-level modules for their responsibilities. Both should depend on abstractions (interfaces).
Abstractions should not depend on details (implementations). Details should depend on abstractions

Answer

true

Question 43

Inversion of Control(IoC) is a design methodology used to build loosely coupled systems by inverting the control of flow (of auxiliary tasks) from the main program to some other entity or a framework

Answer

true

Question 44

Hidden Inputs: In order to check if the user's answer is correct, the program also needs to know that the randomly generated problem was 4x7. The program inserts 4 and 7 as hidden inputs and receives them back string A = request.getParamater("A"); b... validate and output

Answer

true

Question 45

Thymeleaf templates:
Thymeleaf templates belong to "resources > templates" folder.
They have extension ".html", and they are valid HTML files.
The templates (if done correctly) can be opened as files, and correctly displayed by browsers

Answer

true

Question 46

@Controller:
Classes marked with @Controller are added by programmers as ordinary classes and edited

@RequestMapping ("/name.do")
The methods can be mapped to one or more addresses, as shown above (or not mapped at all).

return type of methods:

return "redirect:ListStudents.do"

Answer

true

Question 47

ModelAndView objects:
new ModelAndView(viewName, modelName, attributeName)

ModelAndView object are used as return values of some mapped controller methods

model.addAttribute("form", form)

Answer

true

Question 48

displaying ModelAndView values: return new ModelAndView("output", "loan", loan);

The body of this

tag will be replaced on the server with the proper value. The bodies of such tags are used to check the appearance of the page when the template is opened as the file, without running the application

Answer

true

Question 49

th:object="${student}"
To avoid repetitions, the object name ("student", in this case) can be moved to an enclosing tag

th:if="${#lists.isEmpty(students)}
Content of tags can be displayed conditionally, with th:if, when the condition is true. The condition th:unless is the opposite to th:if

th:each="e: ${#fields.errors('*')}
iteratable data can be printed with th:each notation

th:href="@{addStudent.do}"
th:href links are used when the template is in an running application

th:action="@{removeStudent.do}"
th:action address is used when the template is in an running application

Answer

true

Web App midterm

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