This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
As such, you don't need to have prior knowledge of UML in order to appear for the SCWCD exam. Since you don't have any working knowledge of JSP and Servlet technologies, it'd be a good idea to go for the HFSJ book and try out all the examples in the book. This should make you comfortable with the exam topics.