This week's book giveaway is in the Testing forum. We're giving away four copies of The Way of the Web Tester: A Beginner's Guide to Automating Tests and have Jonathan Rasmusson on-line! See this thread for details.
Struts 1 does not have interceptors. The way to accomplish similar functionality with Struts 1 is discussed here.
BTW, if you can avoid it at all, don't use Struts 1. It has serious architectural problems that are addressed in Struts 2.