This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
As per my knowledge and experience there won't be any questions related to UML in Part I exam but you should be good with it for part II assignment. The Exam Topics in oracle site also not listed any of the UML related stuff in Syllabus for Part I.