This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
In Struts you do this with a combination of the <html:file> tag and a property of type FormFile in your Actionform bean. The best way to learn how to do it is by examining the upload example in the examples war file that comes with the Struts download.