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.
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.