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.
Yes, if by local you mean the system running the servlet container. Servlets don't run in any sort of sandbox, but they are sill subject to any limitations imposed by the underlying operating system, so on a Unix system (for example) you may not be able to write to files owned by another user.