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.
The documentation for the standard Java API should be your first resource when encountering such questions. Find the docs for the version of Java you are using and bookmark them. Learn to navigate it so you can find these odd idiosyncracies between similar methods and other invaluable information about the classes and methods that are available.