95-702 Organizational Communication and Distributed Object Technologies

May 2008

Homework 1             Due: Friday, May 30 2008, Midnight
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       In each part, documentation is required.

       For each of the three exercises below, submit a documented
       servlet, an index.jsp page, and a web.xml document. The 
       documentation will include your name, a description of 
       each piece of code and well-chosen variable names.  

    1. Write an index.jsp page that requests a user's name and 
       provides a submit button. When the submit button is pressed 
       a servlet is executed. The servlet sends 400 hello messages
       back to the browser. Each hello message appears on its own
       line and contains the user's name. For example, if the user
       enters Richard and hits the submit button, the output will
       look as follows:

                     Hello Richard
                     Hello Richard
                     :
                     :

    2. A user can trick this servlet so that it behaves in an unintended 
       manner. For example, a user might enter HTML code into the input
       field. If the input field contains the string "<b>Amy</b>" then
       Amy's name will be echoed back to the browser and displayed in
       bold. Write code in the servlet that prevents any use of 
       anlgle brackets in the user input. Note: a complete answer
       for question 2 does not count for question 1. Question 1 must
       be completed separately.

   
    3. Write a JSP page that allows the user to perform addition
       or multiplication on two, possible very large, integers.
       The JSP page will present three input fields to the user.
       The first two will be used to collect the two integers.
       The third will be used to collect the operation type.
       The only operations supported will be add and multiply.  
       A submit button will be provided and when it is hit
       a servlet will be visited. The servlet will use the 
       BigInteger class to perform the conversions from strings 
       and the appropriate computation. The servlet will return 
       the result to the browser marked up in HTML. You do not
       need to perform data validation in this assignment.