Test contains:

Server s = null;
try {
    s = new Server();
    s.startServer();
   ...
} finally {
    s.stopServer();
}

If "new Server() throws an exception we hit the finally block, s is still null and we then throw NullPointerException instead of the real exception.

The try block should at least start after "s = new Server();" and possibly after startServer() as well.