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.
I'm not aware of a ready-made solution for any of these formats. POI can read XLS, but it's up to the developer to create PDF from that. POI also can read Word documents, but that's reported to be buggy and unsupported, so it may or may not work with the files you have. For RTF, you could write a reader based on the JavaCC parser (which comes with an RTF grammer). All of these would require significant amounts of work.