Objective:

The objectives of this assignment are:

1. To gain an understanding of how some of the common Internet application protocols are designed,
2. To be familiar with how standard protocols are specified in RFCs, and
3. To understand how HTTP and SMTP protocols work and implement them according to their respective RFCs.

In this assignment, you need to implement a multi-threaded HTTP server and an SMTP client. Your HTTP server should implement both the GET and POST methods and should support the following functionalities:

• Your server should support a root and should dynamically generate a default index HTML file and an email form web page when a browser requests one of these files . The index page should have three different links. One pointing to the course web page, one pointing to one of your favorite web sites, and one pointing to the email form web page.
• If the user presses on the email form link, the HTTP server will respond by producing the email form page. This latter will have the following fields:
  • a (From:) field to hold the email address of the sender,
  • a (TO) field to hold the email address of the receiver,
  • a (SUBJECT) field to hold the email subject,
  • a (BODY) field to hold the email body,
  • a (SEND) command button, and
  • a (SMTP SERVER) field which users can optionally fill to designate a specific SMTP server to use. If this field is not filled, your SMTP client should be able to use a default server.
• If the user presses the SEND button, The POST method will be used in this case to send the SMTP request to the HTTP server. This latter will then forward the request received to the SMTP client who will take care of sending this email message to its destination.
• If the server receives an empty request, he should respond by producing the index page.

Both the index page and the email form page should be dynamically generated by your HTTP server using HTML. You should not use any external HTML files for these pages or any other HTML page for this assignment.

Your should work with browsers that are HTTP/1.0 compliant. 

You should not use servlets or any existing SMTP or HTTP classes in this this assignment.

Your program should take a command line argument specifying what is the port number it will use.

  All exceptions must be properly handled.

Extensions:

Completion of one of this extensions will result in a better grade; however, groups of more than one person MUST complete this extension to receive a full grade. It should also be noted that, if you have an idea for a different extension, ask either the instructor or TAs for approval:

1. Enhance your SMTP client to support attachments
2. Support default values in the email form page. The default values should be passed from the client as parameters using the GET method and a properly URL-encoded string as attachment.
3. Implement an interface between your HTTP server and the calendar application you have implemented in PA2.

Grading:

Grading will be split in the following way:

• 60% correctness (Does it do what it's supposed to?)
• 20% error handling (Can it easily be crashed?)
• 20% documentation (Is it easy to read and understand the code?)

Submission:

The due date for this project is October 1^st, 2002, 11:55pm EST. You should use the assignments drop-off box located at the course's WebCT page. Upload a JAR file containing all the relevant documented Java files, along with a README file describing the project and its usage.

Late submissions:

• 10% penalty for a one-day late submission.
• 25% penalty for up to a three-day late submission.
• Submissions more than 3 days late will not be accepted.

Useful Links:

• HTML Tutorials:
  • http://www.ncsa.uiuc.edu/General/Internet/WWW/HTMLPrimer.html
  • http://www.davesite.com/webstation/html/
  • http://www.pageresource.com/html/index6.htm
  • http://www.yourhtmlsource.com/fullindex.html#LESSONS
• RFCs:
  • RFC 1945 (HTTP/1.0)
  • RFC 2821 (SMTP)