Assignment 1 -- Tracking eBay Items

Fengzhou Zheng, Feb. 2004

Description -

Write a program that accesses eBay auctions by item number, and report on their progress, thus providing a useful tracking tool. Such programs will be useful later if you want to gather data for statistical studies. You should probably start by looking around the eBay site a little, just to get familiar with it.

Once you have the number of the item you are interested in tracking, the page you will need to parse has the URL of the form http://cgi.ebay.com/ws/eBayISAPI.dll?MfcISAPICommand=ViewItem&item= nnnnnnnnn. The important thing to note here is that the only element of the URL which changes is the ID number.

Please be extra careful not to interfere with the eBay site.
Use sample pages to test. Thanks.

Requirements -

The program should, at the minimum,

Take as input in some way (command line argument or data file) an ID number provided by the user for each eBay auction to be monitored;
Report the item title, closing time, current number of bids, and current price.

Additional frills are up to you: report whether the auction is closed, report time left, perform periodic tracking, automatically report changes by email, and so on. The sky's the limit. Extra points for good ideas. At the minimum, please hand in a hard copy of a few examples, a very brief description of the method you used, and the printed code. You may be called on to supply working code in digital form. The program and methodology is up to you, but here is some help for those of you who want to do this in Java. One of us (ken@cs) used wget, sed, shell scripts and other assorted UNIX tools. Some of you may prefer Perl.

Hints for Java Solution -

For those of you less familiar with Java^TM, there is a complete description of all Java 1.1 classes and methods at http://www.javasoft.com/products/jdk/1.1/docs/api/packages.html, and there is a good online tutorial at http://java.sun.com/docs/books/tutorial/

We provide a helper class HTMLTokenizer.java, which incorporates the functionality of fetching an HTML file and parsing it into a sequence of tokens. For more information about the interface of HTMLTokenizer.java, see here. We also include three small example programs to demonstrate the usage of HTMLTokenizer.java. They are Test1.java, Test2.java and Test3.java.

Credits: Early Java version by Oren Firestein '01, Java version and HTML documentation by Lisa Worthington GS, revised by Erik Sherwood '00, revised by Fengzhou Zheng GS.

Java is a registered trademark of Sun Microsystems, Inc. EBay is a registered trademark of eBay, Inc.