Although on the surface this seems to be about an arguably advanced topic -- reflective access to private constructors -- I think it's actually a question about basic Java syntax and reading the API documents.
The syntax "HackMe.class" retrieves the java.lang.Class object that represents the HackMe class. It's a convenient shortcut to the same object returned by the static method call Class.forName("HackMe") . The method getDeclaredConstructors() is a method of java.lang.Class, and so we have to fetch the appropriate Class object to call the method on. [ December 19, 2008: Message edited by: Ernest Friedman-Hill ]