PortMapper implementations provide callers with information
about which HTTP ports are associated with which HTTPS ports on the system,
and vice versa.
Concrete implementation of
PortResolver that obtains the port from
ServletRequest.getServerPort().
This class is capable of handling the IE bug which results in an
incorrect URL being presented in the header subsequent to a redirect to a different scheme and port where the port
is not a well-known number (ie 80 or 443).