Oracle API says about this method: " This method may be invoked to move an empty directory. ... When invoked to move a directory that is not empty then the directory is moved if it does not require moving the entries in the directory. ... When moving a directory requires that its entries be moved then this method fails (by throwing an IOException)." I don't understand what that means at all... I tried it and my experience was the opposite. I put three files in a folder (rtf, txt, bmp) and tried to move this folder to another place, with the expectation that it would fail and throw an exception. Well, it didn't. It was smooth, it moved the directory and all of its content to the target place, without any Exception.