// How to start up some other Java program when you don't
// know its name at compile time.

// Have all your dynamically loaded classes implement a common interface,
// called here Delegate. For his method to work, you need the source code for all
// dynamic classes, or the power to ensure they all implement some common interface.

// You might get the list of possible dynamic class names
// from a run-time properties file or by doing a File.list

Delegate d = (Delegate) ( Class.forName( "com.mysite.mypackage."
                            + nameOfClass )
                           .newInstance() );

// To get better control of exceptions, you might use reflection on the constructor
// in place of newInstance.

// Now you can invoke instance methods on your delegate.
// Interfaces don't have any static methods, though you can cast your
// interfaces to classes that do.