Diana Inkpen, Alan Williams
Table of Contents
Lab Facilities
Labs for ITI 1120 will be held in rooms
The computers are various configurations of IBM personal computers. The operating system is Windows XP on all computers.
Please see http://www.site.uottawa.ca/local/labinfo for complete information about the lab facilities.
It is also possible to work on your own computer, if you install the Java Development Kit (JDK). The JDK is available at the web site http://java.sun.com. It is also recommended to obtain the “Dr. Java” development environment available from http://www.drjava.org. For information about how to install the software needed to work on your own computer, see the web site http://www.site.uottawa.ca/~diana/iti1120/WorkAtHome.html.
Course accounts
Using any of the SITE labs requires a SITE computer account. This is different from your general university account. Your university account user identification (user name or “userid”) will be similar to:
awill039 (a contraction of first initial, family name, and three digits)
The SITE account will have the following form of userid:
u0618234 (‘u’ followed by the student number)
The general university account will be used for official e-mail communications – even for the ITI 1120 course – and e-mail should be checked there regularly. The SITE account is only for access to the SITE workstations and network.
If your major is computer science or software engineering, your SITE account will be active for the entire length of your studies. If your major is not one of the above, your SITE account will be activated only during terms in which you take a course with course codes starting with ITI, CSI, or SEG.
Generating a course account
Generating an account is an operation that needs to be done only once at the start of the term. When you generate an account, space on a central disk server will be reserved for you. You will be able to access files stored on this server from any SITE lab computer.
To start to generate an account, you need to access the login screen. You may need to move the mouse on a computer if the screen is blank or a screen saver is running. Otherwise, you should see the “Welcome to Windows XP” screen.
Press all three of the CTRL, ALT, and
Normally, you would login with your SITE userid and password. To generate your account, use “autopass” as the userid, and “autopass” as the password. As you type the characters of your password, they will appear as • characters so that your password cannot be read from the screen. Click the “Login” button to proceed.
The Account Generation system will ask for your student number, and then prompt you twice for a lab password of your choice. It will then ask you to authenticate yourself using a PIN (personal identification number). This is your InfoWeb student services password, which you should have received as part of your registration package. No other password will work. Your Infoweb Student Services password (or PIN) will remain unchanged; it has nothing to do with your SITE account password. The lab password that you have supplied will be the one used for your SITE lab account.
If you do not know what your InfoWeb password is, click on the 'PIN?' button. This will take you to a page that will allow you to obtain your InfoWeb password.
If all went well, the account generation program will indicate which labs your account will enable you to use.
· If your PIN (Infoweb password) was not correct, you will need to find out what is your PIN (it was sent to you in your registration package). You should contact InfoService, at http://www.uottawa.ca/student/infoservice/ or at 562-5700.
· If you are not registered to a course that grants access to an account, the system will indicate this. Note that the registration information that is used to generate accounts may be few days old. If you have registered just recently, come back in a day or two.
· If you forget your password, simply regenerate your account using the same procedure.
· If the Account Generation system fails because of system errors (this is unfortunately unavoidable), report this to the consultant on duty, then try again later.
Logging In
An unoccupied computer should be showing the “Welcome to Windows XP” screen. If the computer has been idle for a while, the screen may be blank and you should wiggle the mouse or press any key to turn on the screen.
Press all three of the CTRL, ALT, and
Enter your userid in the “user name” area. Type your password in the password box. As you type the characters of your password, they will appear as • characters so that your password cannot be read from the screen. Click on the “Login” button or hit enter to log in.
The login process may take a few seconds. When the login process has finished, the screen should be similar to what is shown in Figure 1, although the information shown is updated regularly with the latest news.
Figure 1: Screen after a successful login
You can now use the computer, and you will have access to your files stored on the central file server.
Logging Out
When you are finished your session, it is critical that you log out, to protect your files from the next user. Double-click on the following icon to log out:
Figure 2: The logout icon
Do NOT turn the power off or shut down the machines.
The SITE Environment
Here are some important features of the SITE lab environment that may be different from your own computer.
On a Windows system, there are several different methods of storing files on your computer. These are represented by “disk drive” letters. While these can vary among different computers, you may be familiar with “C” being the internal disk drive, “A” being a diskette drive, and “D” for a CD or DVD drive.
If you store your files in the “My Documents” folder, these files are normally stored on the C drive. The C drive usually also includes all the software installed on a computer.
There are some differences in the SITE lab configuration for several reasons:
· You may be using a different computer during your next visit to the lab, and you will need access to your files.
· We want to be sure that you have access to only your own files during your session, and not those of students who used the computer previously.
· In case an important system file is deleted accidentally, we want to be able to restore the computer to its original state.
· We want to protect the SITE lab computers against malicious software such as viruses, worms, spyware, and ad-ware.
Therefore, keep the following in mind as it is very important:
When
you log out from the computer, the C drive is restored to a standard
configuration.
This means that any files that
you stored on the C drive will be erased at the end of a session. This includes files stored in the
“My Documents” folder. These files cannot be recovered once erased.
To provide permanent secure file storage, and to provide access to your files from any SITE lab computer, your files on the central file server will be made available on drive H when you log in. Here are the notable drive letters you will see on a SITE lab computer.
A: The diskette drive. This can be used to transfer small files to other systems with similar drives. Although SITE lab computers have diskette drives, most newer computers do not include a diskette drive.
C: The local internal disk drive of the computer. The “My Documents” folder is on this drive. The contents of the C drive are not available from other computers.
E: The compact disc (CD) drive. The CD drives in the SITE labs are read-only; you will not be able to burn a CD from these computers, nor can you read from a DVD.
F: If you plug in a flash memory stick to the universal serial bus (USB) port, it will appear as drive F.
H: File space reserved for your account on the central file server. It will be available from any SITE lab computer, and can also be accessed from the Internet. This is where you should store files that you want to keep permanently.
You can store files temporarily for a session on the C drive, but any files that you want to keep permanently should be copied to the H drive (or put on a diskette or flash memory stick) before you log out.
There are other drives that store various software applications that are available on the computers.
Printing from SITE labs
SITE provides line printers and laser printers for SITE students. Line printers are free for both graduate and undergraduate students. All Students have access to Relmon printers and must purchase a copy card to print documents using the Relmon printers.
Relmon printers are maintained by Computing & Communications Services (CCS).
Information about the names, locations and usage of SITE's printers are summarized in the following table:
|
Printer name |
Location |
Description |
|
uglp1 |
|
High speed line printer |
|
uglp2 |
|
High speed line printer |
|
relmon |
CBY Hall, 1st floor. |
Pay-per-use laser printers. Requires a photocopy card. |
Note that the high speed line printers are not capable of handling graphics or advanced fonts. If accented letters are sent, they will be printed without the accent. Use the line printers to print programs and rough copies of documentation.
When you print a file using the Relmon system, your file is sent to a central print server. The print server holds your files until you are ready to print (and pay) for them. You can use any of the Self-Service printers located around campus to print. The printers are always available, the only limit being the hours in which the building is unlocked. At each printer there is a terminal to display and select the file(s) you want to print, and a photocopy card reader to accept payment.
You pay for printing in the same manner as when you use photocopiers on campus. There are copy card dispensers at various locations on campus from which you can purchase a copy card and load it with a monetary value. The card is then debited as you use the self-serve photocopiers or printers
Additional information is available from the following web sites:
· SITE printing documentation:
http://www.site.uottawa.ca/local/labinfo/printing.shtml
· Guide to self-service printers on campus, and their locations.
http://www.uottawa.ca/services/ccs/docs/cyberleap/relmon/relmone.html
The Virtual Campus
The Virtual Campus is the university’s on-line course management system. The Virtual Campus provides the following facilities for ITI 1120:
· Access to the course webpage (also available from outside Virtual Campus)
· Electronic assignment submission
· Discussion forum
· Current grades
Students registered in ITI 1120 should have access to the ITI 1120 on-line course.
The virtual campus is available at the following web site:
https://maestro.uottawa.ca/index.asp?LANG=EN
The login area is in the upper right corner of the web page. To log in, enter your student number and your InfoWeb password (do not use the password from your SITE account).
After logging in, you will see a screen with the list of courses to which you have access.
Click on the ITI 1120 course to access the course content.
There is a discussion forum that is essentially a bulletin board where you can post messages for everyone in the course to read. All students, all teaching assistants, and the professor will be able to read any message that is posted. The professor reserves the right to delete any inappropriate messages posted to the forum; keep in mind that your name will be posted along with the message.
The “My Grades” tool lets you see how you are doing in the course. Assignment, midterm, and final exam grades will be available here.
The discussion forum is the preferred way to ask questions about the course. If you have a question, it is likely that someone else may be wondering about the same question. If you post the question, everyone can benefit from the answer.
An important component of the virtual campus is the on-line assignment submission and return system. Assignment descriptions will be made available on-line only; they will not be printed on paper. If you click on the “Assignments” icon, you will see the list of assignments for the course. Assignments will become available as the course progresses. To view a particular assignment, click on its title.
The maximum grade for the assignment and
its due date are shown at the top of the page. The instructions area will provide
general instructions, such as whether the assignment is to be done individually
or as part of a team. The lower part of the page is used to submit an
assignment. When you have prepared
the file you want to submit as your assignment, click the “Upload
file” button. This will allow
you to locate and select your assignment file. Once you have uploaded the file, check
to make sure that you have the correct file. If you would
like to receive an e-mail confirmation when the assignment is submitted, enter
the address to which you would like the message sent.
Click on “Submit assignment” to complete the process. At this point, the status of your assignment will change from “Not submitted” to “Not graded.”
You can practice assignment submission using “Practice Assignment 0”. It will not be graded, it is intended for you to get used to the system.
For ITI 1120 assignments, you will be allowed to remove the files and re-submit your assignment at any time up to the assignment due date and time. At that point, all files are locked in, and the teaching assistants can start grading the files.
When your assignment has been graded, the status will change to “Graded”, and there will be an area where you can download the files that include feedback from the teaching assistant who graded the assignment. There is also a comments box and the actual grade. Files provided from the teaching assistant will use the Microsoft Word reviewing features to provide feedback, as shown in Figure 3.
Figure 3: Sample of assignment feedback
When viewing the files, be sure that you have the “Markup” feature turned on in Microsoft Word. The text in Figure 3 describes how to do this.
It is very important to read this section, as marks will be deducted if the procedures described here are not followed.
· All assignments must be submitted electronically using your virtual campus account.
·
Don’t
wait until the very last second to submit your assignment; processing may be
slow near deadlines.
All the files for one assignment must be placed in a folder named, aX_studentId, for example, student 0618234 submitting assignment 4 would put all assignment files in a folder named a4_0618234. The folder must contain no files except those related to the assignment. If you are working as a team, choose only one member of your team to submit the assignment, and use the student number of that person for the folder name.
Please ensure that you use this naming convention, as the teaching assistants will have files from many students and multiple assignments downloaded to their computers. We want to ensure that each assignment submission has a unique name and avoid problems with duplicate file names.
For each question on the assignment the folder should contain:
· A Microsoft Word file (.doc) file or Rich Text Format (.rtf) file. If you are working on a machine that does not have Microsoft Word installed, you can use the “Wordpad” program that comes with Windows to create an .rtf file.
· For questions that do not involve programming (e.g. software models and diagrams), this file will contain the answer to the question. In this case, this is the only file that is necessary.
· For questions that involve programming, this file will be used for the teaching assistant to give comments about your code. Create the .doc or .rtf file as follows:
· Set the font to be “Courier new” and the font size to be 10.
· Select all text in the .java file. Copy it and paste it to the Word or RTF file.
·
Java
source code files (.java)
· It is only necessary to include code from .java files that you have created, or modified from the original version posted with the assignment. Files with Java code that were posted with the assignment but were not modified by you can be omitted.
· Class files (.class) compiled from the .java files.
· The names of the file containing the main method must indicate the assignment and question numbers: for example, if question 2 on assignment 4 requires submitting a program, you should have 3 files for that question named A4Q2.doc, A4Q2.java, and A4Q2.class.
· If the program requires more than one Java class, additional .java and .class files should be included. For example, if question 2 on assignment 4 also uses a class that you have created called Hello, submit the files Hello.java, Hello.class, and Hello.doc. Classes without main methods do not have to follow the AxQy convention.
Create
a .zip file containing the contents of the entire folder. To
“zip” a collection of files is to do the two following operations:
· Compress each file so that it uses the minimum amount of space.
· Put all of the compressed files inside of one file, so that everything is in one file in a way that the original folders can be recreated.
In Windows, this operation is called “Send to compressed folder”. There are also many file compression programs available (see warning below). For example, “Ultimate Zip” is installed on SITE lab computers.
Your assignment submission file should be named aX_StudentId.zip, where aX_StudentID was the name of the original directory. For example, student 0618234 submitting assignment 4 should create a zip file with the name a4_0618234.zip
To do this using one of the SITE lab computers, go to the parent folder of aX_StudentID and click the right mouse button on the icon of the folder aX_StudentID. Select “Add to aX_StudentID.zip”. This will create the zip file, which is a single file that contains compressed versions of your original files.
· Submit the zip file via the virtual campus assignment submission system (click here to go to the Virtual Campus)
· Assignments that do not conform to the above procedure will not be graded.
WARNING: Some file compression programs produce files in “RAR” format. This is NOT the same format as the ZIP format. The SITE labs do not have a program that can read .rar files. If you use a file compression program on your computer instead of the default “Send to compressed folder” from Windows, check very carefully that it produces .zip files. If you submit a .rar file, and the teaching assistant cannot read the file, you will get zero for the assignment.
Identification
The following information must be included at the start of every .doc file and as comments at the start of every .java file. Every program should also print this information as the first part of the output.
· Course: IT1 1120
· Assignment number
· Question number
· For each team member:
· Family name, Given name
· Student number
· Section: A or B
Programming Standards
In
industry, coding conventions help to reduce errors during program maintenance;
in most cases, it will be someone else who has to understand the program well
enough to change it without causing new problems. Many companies also
have mandatory code inspections for quality control, where you are not allowed
to contribute program code to a software product until it has been read out
loud by someone else in a meeting attended by several software
developers. Using standard coding conventions helps make your programs
easier to understand by others (especially teaching assistants!).
For ITI 1120, approximately 10% of the grade for each assignment will be for
following the course programming standards, and marks will be deducted for
violations.
It is recommended to follow the general form of the Java code conventions at:
http://java.sun.com/docs/codeconv/html/CodeConvTOC.doc.html
The above web site is very detailed, and includes many parts of Java that are
beyond the scope of ITI 1120.
In addition, for ITI 1120 the following standards MUST
be respected:
Input / Output
· Output should be nicely spaced and easy to understand. In particular, it should be easy to understand the output WITHOUT looking at the program listing. This means that for every value in your output you must print a short message explaining the meaning of the value.
· Before your program requests input values from the user, it must print a prompt describing what the user is required to enter.
Variables
· Identifiers should be as meaningful as possible. Follow the standard upper-case/lower-case conventions for Java programs.
· Method names and variables usually start with a lower case letter and then any additional words that are part of the name are capitalized. There are no spaces or underscores between words. The first word of a method name is often a verb.
·
Examples: calculateStudentGrade(
), aNumber
· Class names should start with an upper case letter. Class names are generally a noun.
·
Examples: Student, Course
· Only declare variables that are actually used.
· Do not use the same variable for different purposes.
· Every variable should have a comment describing its purpose. Be brief. This is called a data dictionary - it should be placed at the beginning of every method, either before or beside the declarations.
· Do not use "global" variables. All values needed by a method must be passed into it as parameters and all values it produces or modifies must be returned as results or passed through parameters.
Program Structure
· Good structure is very important. Decompose your algorithms/methods into meaningful sub-algorithms/methods whenever this improves clarity.
· Each method (including "main") should be preceded by comments describing its purpose and the algorithm it uses (if the algorithm is very simple, it need not be described). These descriptions should be brief.
· Your program must be indented in a systematic way that reflects the nesting of its statements.
· The following are some exceptions to the coding conventions at Sun’s web site:
· Branch statements must always follow the following form – namely, the braces and else clause must always be present and formatted as shown even when the Java language specification allows them to be omitted. Multiple if {} else if {} else {} statements should not be used.
if
( condition )
{
// the true part
}
else
{
// the false part
}
· If either part requires no action, it should be as follows:
{
; // do nothing
}
· Loops must follow one of the two forms – namely the braces must always be present and formatted as shown even when the Java language specification allows them to be omitted.
while ( condition )
{
// the loop body
}
(or)
for ( initialization; condition; increment )
{
// the loop body
}
· The following should not be used:
do
switch
break
+=, -=. *=, /=
condition ? trueClause : falseClause
· Increment and decrement operators can only be used in the following forms
aVariable++; // no other code on this line
aVariable--; // no other code on this line
for ( initialization; condition; loopIndex++ )
Restrictions
· Everything you submit (files and programs) must compile and run using the Java Development Kit (JDK) version on PCs in the SITE labs. “It works on my own computer,” is not a valid excuse if there are compatibility problems with your program.
· You may only use features and library methods of Java that have been presented in class or labs at the time an assignment is due. For example, you may not use Java's arrays before they are covered.
The Dr. Java Environment
The Dr. Java environment is an
“integrated development environment” (IDE) that will be used for
the ITI 1120 course. Dr. Java is
available in the SITE labs, and you can also download your own copy for free
from http://www.drjava.org. Dr. Java has been developed at
[Note that you can use any method that you wish to enter and compile programs. However, the teaching assistants will be able to give you help on using Dr. Java. If you use another IDE, you are on your own to learn how it works.]
If you start up Dr. Java, you will see a screen similar to Figure 4, for the latest stable version (that is probably the one installed in the lab).
You may not see the line numbers; if you want to turn them on, click on the Edit menu and select “Preferences”. In the categories area, click on “Display Options” and then check the “Show all line numbers” box.
Figure 4: Dr. Java window (latest stable version)
The main screen area is partitioned into three parts. The upper right area is an editing area where you type in Java code. Dr. Java will help with Java code entry in the following ways:
· Java keywords, comments, and strings will be highlighted in various colours.
· Code will be indented properly.
· If there are problems compiling, the line with the problem will be highlighted.
The area on the left is a list of files that you are currently editing. In Figure 4, (Untitled) appears in this area because there is no file associated with the empty editing window. You can edit several files at once, and click on a file name in the list to move between files.
The area at the bottom has three views indicated by the “tabs”: Interactions, Console, and Compiler Output. Currently, the “Interactions” view is selected, and you can move from one view to the other by clicking on a tab. Sometimes, Dr. Java will change the view automatically when it is appropriate. When you compile a program, the output from the compiler will appear in the “Compiler Output” view. The “Console” is the area for text-based input and output for a Java program, and this is where you will see the results of running your program.
It is a tradition among programmers that when learning a new language that the first program you write will print “Hello, world!” In Java, the following program will print this message to the console:
public
class Hello
{
public static void main(
String[] args )
{
System.out.println(
″Hello, world!″ );
}
}
Be very careful to type this exactly as
shown, including the semicolon on the line with the message to print. By entering the above, you have created
a “class” called Hello. Java
programs always consist of one or more classes.
You are now ready to save the file. Note that a * has appeared after (untitled) to indicate that there are changes that have not been saved. Click on the “Save” button
to save your file. You can choose any folder you wish. Notice that in the “File
name:” and “Files of type:” areas, Dr. Java has filled in
“Hello” – the name of the class – and Java source
files. This means that the proposed
name of your file is Hello.java ; it
is important for Java that the name of the file ends in .java to indicate Java source code, and it is also very important that
the name of the file matches the name of the class inside the file. Therefore, you should
accept the proposed names by clicking Save.
Note that (untitled)* in the left area has changed to Hello.java, and
the * has been removed to indicate that there are no unsaved changes. The complete folder path of the file
also appears at the bottom of the screen.
The buttons in the Dr. Java window related to operations with code are the “Compile”, “Run”, “Test”, and “Javadoc”. A Java program must be compiled before it can be run. The compiler checks that your program obeys the rules of the Java language, and then translates the code into a format that the machine can understand. Clicking the “Compile” button will compile the current file. Output from the compiler will appear in the lower area. If everything was okay, you will see the message “Last compilation completed successfully” in the compiler output view.
To run a program in Dr. Java, you can use the “Run” button from the left corner of the screen. To run a program from a console window, you could have typed java Hello, where java is the command to run a Java .class file. This command has appeared in the Interactions window as a result of selecting to run the method from the menu. Some people prefer to use menus, while others prefer to type commands.
Beneath the command is the output from your program. We have successfully printed “Hello, world!” If you want to see a view of the program output without the interaction commands, click on the Console tab.
When there is a compile error, you may see something like Figure 5 (the figure shows an older version of Dr. Java):
Figure 5: Result when there is a compile error
In this case, the closing ″ has been omitted in the println( ) statement.
For each problem, the compiler message indicates the file and line number of the problem, followed by a message of what the compiler believes is the problem. For the first problem, both the message and the corresponding line in the file are highlighted in yellow. If you click on the second problem in the compiler output window, the highlighting will move to the location of that problem, as shown in Figure 6.
The message unclosed string literal means that the compiler could not find the closing double-quote character to indicate the end of what to print on the screen.
Figure 6: Locating errors
The second error message, ′)′ expected is related to the same problem, and can be confusing because the ) is actually present in the program. If you look carefully at Figure 5 and 6, you may notice that the characters ) and ; are coloured in red, and this means that the compiler is assuming that these characters are part of what is included in the message to be printed on the screen. It is only after the compiler reaches the end of the line that it realizes that the ″ is missing. Now, the compiler wants to match the ) character for the println( ) statement, but the next character is a brace on the following line and the compiler reports an error at that point.
In fact, restoring the ″ will eliminate both error messages.
As you can see, interpreting compiler messages can be tricky and this is one of the things you will have to learn in the course. Sometimes, as in the case we have seen here, several compiler messages can result from just one problem in the code. In other cases, after fixing one compiler problem, more problems that were obscured by the first problem can appear during the next compile. If the messages from the compiler do not appear to make any sense, it helps to remember that the compiler reads one character of your program at a time in the forward direction, and will not back up. The compiler can only print a message when it is sure there is a problem, and that is why it cannot tell that the ) was not meant to be part of the message to be printed.