95-702 Organizational Communications And Distributed Object Technologies
Homework 2 Due Midnight on Friday, June 13, 2008

For full credit, your code will work and be well 
documented with well chosen variable names.
Overall, it will be easy for the grader to read 
your code.

Voting with a browser
=====================

(1) 30 Points. Using Eclipse and Tomcat, write a 
JSP page and a servlet that uses cookies to allow 
a user to vote for one of three candidates but also 
determines if an individual has voted for president 
more than once. The initial page will ask the user 
to vote for McCain, Clinton, or Obama. After the 
user selects a candidate execute a servlet that 
writes the user's choice back to the browser and 
to a cookie. If the user votes a second time, from 
the same browser with cookies turned on, reject 
the new vote and tell the user who they already 
voted for. This is not actually secure but it 
allows us to explore the use of cookies.

Post this project to the assignment section of 
blackboard.

(2) 30 Points. Add a hand written shared object 
(singleton) to the system above and use it to 
collect a vote tally. A second report page 
should be available to a 
voting administrator with user name "Jethro" and 
password "cementpond". Anyone with this username 
and password will be able to collect the vote tally for 
each candidate at any point in time. Perform your 
username and password check within your servlet. 
(Tomcat can also be configured to do this but 
here we will do it ourselves.) In going from 
question 1 to question 2, you will need to modify 
the web.xml file. You may have to restart Tomcat to have 
the new web.xml file accepted. The modification 
to the web.xml file needs to be done correctly. Plenty 
of example web.xml files are available on the
internet.

Post this project to the assignment section of 
blackboard.

Voting with a web service
=========================

(3) 40 Points. Write a simple voting web service 
and two clients using JAX-WS 2.0. 

The ballot for this voting service will contain three 
individuals: "Clinton","Obama", and "McCain".

You may assume that registered voters have been 
issued identification tokens. These are the 
integers 0,1,2,...9. There are only ten 
registered voters.

The web service will have the following interface:

        // If this is a registered voter and the candidate is on the
        // ballot and this voter has not voted before then this 
        // method adds 1 vote to the candidate's vote tally.
        // A status message is returned to the caller indicating
        // the success or failure of this method call. The status
        // string may read "Vote accepted", "No such candidate" or
        // "This voter has already voted once." 
  
        public String vote(int voterIdentification, String candidate);
       
        // If the voting administrator's name and password are both 
        // correct and the candidate is on the ballot, this method 
        // returns the number of votes cast for the candidate. 
        // The method returns a -1 if the candidate's name is not
        // on the ballot. It returns a -2 if the administrator's 
        // name is not correct and returns a -3 if the password is 
        // not correct.
       
        public int total(String candidate, String adminName, String adminPassword);

Two command line clients will access this web service. The first
will be called Voter.java and will run as shown:

        java Voter
        Enter voter ID:  8
        Enter candidate: Obama
        Vote recorded

        java Voter
        Enter voter ID:  8
        Enter candidate: Obama
        Illegal vote (you already voted)

        java Voter
        Enter voter ID:  9
        Enter candidate: Clinton
        Vote recorded

The second will be called Admin.java and will run as shown:

        java Admin
        Enter admin user name: Jethro
        Enter admin password:  cementpond
        Enter candidate: Obama
        Votes for Obama = 2

Submit at least three Java files for this part of 
homework 2. One Java file will implement the 
web service and two Java files will implement
the clients. 

Be sure to test your Admin client with illegal
user names and passwords. 

Use command line shells for the web service 
part of this assignment. I have had trouble getting
Eclipse to run the APT tool. It works fine
from the DOS screen.

JDK 6 for the Apple has recently come out. I have 
not tested JAX-WS on the Apple. It is suggested
that you use a PC for this homework.