UNIVERSITY OF TORONTO
Faculty
of Arts and Science
DECEMBER EXAMINATIONS 2001
CSC 309H1 F
Duration – 3 hours
Examination Aids: One double-sided 8.5”x11” paper
containing notes
NAME ______________________________________________________
STUDENT NUMBER ______________________________
|
PART I
(Short Answers): _______ /50
|
|
|
|
PART II (Programming): ________/50
|
|
Q. 25
________/5
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Q. 28
________/5
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|
Q. 26
________/5
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Q. 29
________/5
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Q. 27
_______/15
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Q. 30
_______/15
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|
|
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Total:
___________/100
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Part I of this examination
is a series of short-answer questions. Answer theses questions in the spaces
provided on this examination paper. There is no need to use more space than is
provided. If you must, then use the back of the examination paper and so
indicate in your answer.
Part II of this examination
is a series of programming exercises. Answer these questions in the examination
booklets provided.
General Advice:
·
Skim through the entire exam before beginning your detailed work, to get
a sense of where best to spend your time; if you get stuck on one question, go
on to another and return to the difficult question later
·
Show your work, not
just the final answer. Partial credit
will be granted in cases that demonstrate correct reasoning, even if an error
leads to an incorrect final result.
·
For the short answer
questions, you may answer in point-form rather than complete sentences, but be
clear.
·
For the programming
exercises, if unsure of API details or language syntax details, try your best
and include a comment for part marks indicating what you are attempting to
achieve.
Total Pages = 13 (including this cover sheet)
PART I (short answers) (total
marks = 50)
1.
[2
marks] What is the relationship between XML, SGML, HTML4 and XHTML?
2.
[1
mark] What is CSS? What has been
deprecated in favour of CSS. Why?
3.
[2
marks] Describe the relationship of Unicode, ISO-8859 and ASCII. Which is
better? Why?
4.
[10
marks] Explain the purpose of each line, and each part of each line, in the
following XHTML prologue.
[1] <?xml
[2]version="1.0" [3]encoding="iso-8859-1"?>
[4]<!DOCTYPE
[5]html [6]PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
"DTD/xhtml1-frameset.dtd">
[7]<html
[8]xmlns="http://www.w3.org/1999/xhtml" [9]xml:lang="en"
[10]lang="en">
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
5.
[1
mark] When a Unicode document is sent to a browser, is it always two bytes per
character? Explain.
6.
[2
marks] Describe how GIF compression works. What is the main lossy step?
7.
[2
marks] Describe how JPEG compression works. What is the main lossy step?
8.
[1
mark] When would you use GIF on a Web page. When JPEG? Why?
9.
[2
marks] What is dithering? What is
anti-aliasing? How does each affect the file size of GIF images?
10.
[1
mark] If 1000x2000 pixel image is to displayed on a web page in an area of
100x200 pixels, what are the pros and cons of shrinking the image size ahead of
time versus downloading the larger image and allowing the client browser to
shrink it?
11.
[2
marks] In the presence of multiple scripting languages that a browser can
interpret, what is the standard fashion of indicating the script language in
intrinsic event scripts and in <script> element scripts giving an example of each.
12.
[2
marks] Describe the mechanisms used to protect against malicious code in Java
Applets.
13.
[2
marks] What mechanism is used to translate a symbolic Web address such as
yahoo.com into an IP address? Where is
the data used in the name to address translation stored?
14.
[4
marks] For the following form:
<form
method="get"
action="http://foo.cs:80/cgi/doit.pl?greeting=hello">
<input
type="hidden" name="top" value="login">
<input
type="hidden" name="bot" value="passwd">
<input
type=”submit”>
</form>
i)
show
the complete HTTP request
ii)
show
the complete HTTP request if the method were post instead of get
15.
[1
mark] How many round-trip times (RTT’s) are saved in loading a Web page
containing 5 embedded image objects through use of persistent connections?
16.
[2
marks] The Internet's IP network layer is responsible for end-end packet
delivery from sender to receiver.
i)
Why
does the Internet use an additional end-end transport layer between the sender
and receiver?
ii)
Which
transport layer protocol does HTTP use?
17.
[1
mark] How does a proxy server know when to refresh its content?
18.
[1
mark] What programming languages can be used for CGI programming?
19.
[1
mark] Can a CGI program return anything other than HTML files? How?
20.
[2
marks] (a) How is an HTTP cookie sent from the HTTP client to the HTTP
server? (b) How does an HTTP client
decide whether to send a cookie to an HTTP server?
21.
[2
marks] Suppose I receive a legal document with a digital signature based
public/private key technology. How can
I be sure that the document has not been altered from the original? How do I know that the signature really
belongs to the person who claims to have sent the document?
22.
[4
marks] In the CGI protocol:
i)
How
is the part of the URL after the '?' passed to an executing program?
ii)
For
an HTTP POST request, how is the posted data presented to the executing
program?
iii)
How
does a CGI program pass the HTTP response data back to the server after a GET
request?
iv)
Does
the server parse this data or forward it directly to the client browser? Why?
23.
[1
mark] How does the Tomcat servlet engine implement sessions?
24.
[1
mark] Your company’s VP of Marketing has just issued a press release announcing
full support for Oracle in all products; problem is, your product actually
supports Pointbase. As the manager of a
servlet development unit, your programmers will have to create new versions of
servlets in order to provide Oracle support.
Show the lines of code your programmers will have to modify in servlets,
as they would appear in the current Pointbase version.
PART II (to be answered in examination booklets
provided)
25. [5 marks] Develop an XML
application for keeping track of your DVD collection.
Important
information about each DVD are
·
Title
·
audio
formats ('dd' or 'dts' combined with one of 'mono', 'stereo', '5.1',
'6.1') (one or more of them)
·
video
format ('anamorphic' or not plus one of 'standard' or 'widescreen') (one or more of them)
·
special
features (name plus a brief description) (zero or more of them)
Provide
a DTD plus a short sample XML file.
Ensure
your XML tags are in their own namespace: 'http://www.cs.toronto.edu
/csc309/exam/dvd'
26.
[5
marks] CSS
i)
Write
a css that eliminates space above each <ul> and below each <h1>
tag.
ii)
Do
the same thing, but define classes nospaceabove and nospacebelow, and show an
example HTML file using it.
27.
[15
marks total] Write a Web page (and associated program scripts) that presents a
form asking for the user's name. After
the user enters their name and hits a 'Done' button, a new Web page displays
"Hello <name entered>”.
i)
[5
marks] First write this Web page using exclusively client-side code
(Javascript).
ii)
[5
marks] Then write it using CGI-bin code in PERL.
iii)
[5
marks] Then write it using Servlets.
28.
[5
marks] Write a Java Applet called "PlaySound" that alternately plays
(in a loop) the indicated sound clip and stops it when the method togglePlay()
is called. (The sound is supplied as
parameter "sound" from the <applet> tag and is a general URL). Give an example HTML page that displays an
image and toggles the sound playing when the user clicks on the image.
Hint: There is an interface java.applet.AudioClip with methods loop()
and stop(). The java.applet.Applet
baseclass has the method
AudioClip getAudioClip(java.net.URL url)
29.
[5
marks] Use cookies and CGI/Perl to implement a Welcome page that greets a user
with a "Welcome Back <user>" if the user has already been to
the site, or a page that queries the user's name if he/she has not.
30.
[15
marks] Write a servlet to implement AcroCat, the acronym catalogue. Your servlet will interface with the user
through a single page with two parts:
i)
Upper
add acroynms section, that provides form-based input for user-definition of new
acronyms,
ii)
Lower
catalogue display, that presents the existing catalogue entries in the form of
a table, with acronym names in bold font.
A sample of what your page would look like after three entries had been
made is shown below. To keep things
simple, you need only implement adding new acronym entries, not modification,
deletion or sorting of existing entries in the catalogue. Your servlet should ensure that concurrent
AcroCat execution by multiple users does not result in any loss of data (new
definitions being added by concurrent users). Use a relational database for persistent
storage.
