Using UML: CS4 example

What else would you like to see here? Please suggest improvements, or better still send them, to me)

Here are the source files, to compile with Java 2 (aka 1.2) (we make use of the collection classes).

Plus a couple of classes we didn't want to discuss in the chapter but which are necessary to make the thing work: To compile and run, you'll need to do something like "javac" followed by "java Login".

Possible points for discussion/further work: