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.
Neither requestDispatcher.forward nor request.sendRedirect will stop the execution of your request on their own.
It is always a good idea to follow a call to either with a return statement. Another approach is to structure the flow of your page with if statements so that the the call to forward or sendRedirect are always the last call in their respective branches.