Programming Exercise I: my memento by using J2ME

Programming Exercise I: My Memento by Using J2ME

Absolutely no copying others' work

Due Date
Friday, October 14, 2005 in class. Turn in all hard-copy of J2ME source code with the password (one and only one password for all exercises) to download source code on-line.

The Objectives
Design and implement a prototype of a personal memento for handheld devices by using J2ME (Java 2 Platform, Micro Edition).

Interface I (after building the project Memento and running the J2ME emulator)

For how to use J2ME emulator, check Use J2ME.

Interface II (after launching the project Memento from Interface I)

Help is an online help. It explains things which may confuse users.

Interface III (after selecting Display from Interface II)
- Selecting Main will display Interface II.
- Selecting Exit will display Interface I.
- Display the memento items if their messages contain the keyword entered. If no keyword is entered, display all items.

Interface IV (after selecting Submit from Interface III)

Interface V (after selecting Enter from Interface II)
- The current date and time are automatically inserted, for example, by using the following Java code:
```
   java.util.Date  d = new java.util.Date( );
   String          s = d.toString( );
```
- The current temperature is automatically retrieved from the Internet such as Yahoo Weather and Google Temperature.

Posting Your code
For each exercise, students need to post the code on the Web by using CGI (Common Gateway Interface) technology. Create a Web interface at http://people.cs.und.edu/~userid/handheld/exercises/ by following the steps below:

Apply for a UND Aerospace Unix account at the helpdesk in Room 160, Clifford Hall.

Follow the instructions at Web Hosting to create an exercise interface, whose HTML script can be found from here, as below:

Select an Exercise and Enter the Password to Display the Code.
Exercise 1 Exercise 2 Exercise 3 Exercise 4 Password:

Display the Code is for the instructors to download the exercise code. Be sure the code can be built and run without further processing after the instructors save the code.
Help is an online help. It explains things which may confuse users.
Passwords has to be submitted with the hard copies of the first exercises.

Put the HTML script to the file ~userid/public_html/handheld/exercises/index.html . The only thing in the script you have to modify is to change the userid in

  <form method="post" action="http://people.cs.und.edu/~userid/cgi-bin/handheld/code.pl">

to your Unix account identifier.

Follow the instructions at Using CGI at the stewie Server to write a CGI script. The following CGI code is to receive the data entered by users and display the J2ME code accordingly:

~userid/public_html/cgi-bin/handheld/code.pl


#!/usr/bin/perl
read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
@pairs = split(/&/, $buffer);
foreach $pair (@pairs) {
  ($name, $value) = split(/=/, $pair);
  $value =~ tr/+/ /;
  $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
  $value =~ s/~!/ ~!/g;
  $FORM{$name} = $value;
}
if ($FORM{button} eq "Display the Code") {
  if ($FORM{password} eq "password") {
    print "Content-type: text/plain\n\n";
    if ($FORM{exercise} == 1) {
      system ("cat Exercise1.txt");
    }
    elsif ($FORM{exercise} == 2) {
      system ("cat Exercise2.txt");
    }
    elsif ($FORM{exercise} == 3) {
      system ("cat Exercise3.txt");
    }
    elsif ($FORM{exercise} == 4) {
      system ("cat Exercise4.txt");
    }
    else {
      print "\n\n\n     No such exercise: $FORM{exercise}";
    }
  }  
  else {
    print "Content-type: text/html\n\n";
    print "<br><br><center><font size='+1'><b>Wrong password: </b>";
    print "<i>$FORM{password}</i></font><";
  }
}
elsif ($FORM{button} eq "Help") {
  print "Content-type: text/html\n\n";
  system ("cat help.html");
}
else {
  print "Content-type: text/html\n\n";
  print "<br><br><center><h2>No such option: ";
  print "<i>$FORM{button}</i></h2></center>";
}

You have to change the password “password” to a password you pick and write the password on the hard copy of the first exercise.

For security, perform the following operations:
```
  shell> chmod 700 Exercise?.txt* 
  shell> chmod 711 code.pl*
```
to block all read/write accesses from others to the files Exercise?.txt and code.pl . Therefore, only users of this interface knowing the password can access the exercise source files.

The instructor will save the code in the file Exercise1.java. The project will be named Memento and the startup program (class) name is Exercise1. Students take full responsibility if the downloaded code is not working.

Netscape 7.2 will be used to download code. Be sure your system is working on Netscape 7.2. Note that different browsers may not be compatible.

Evaluation
The following features will be considered when grading:
1. This exercise will not be graded if the system interface can not be found at http://people.cs.und.edu/~userid/handheld/exercises/.
2. Sun Java Wireless Toolkit 2.3 Beta emulator of DefaultColorPhone devices will be used to grade the exercises.
3. Persistent storage has to be used. That is the instructor will exit your application and re-enter it during grading.
4. Before submitting the exercise, test it comprehensively. Absolutely no extra points will be granted after grading.
5. If not specified, no error checking is required, i.e., you may assume the input is always correct for that case. For example, if no items are selected in Interface IV, then Delete will not be selected.
6. Each function will be tested extensively.
7. User-friendliness will be heavily considered. In the past, some exercises were awkward. Made the grading difficult.
8. The interfaces shown are basic requirements. Free to design your own interfaces.
9. The hard-copy exercises will be kept until the end of this semester. They will be used to check against others' exercises. The instructor will inform you the exercise evaluation by emails after grading.