This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
HTML is just text - you can use the classes in the java.io package to create whichever HTML content you desire. You won't be able to use Struts (or any other web framework) to help generate the file if the code is not running in a servlet container, though.