Should I use CGI or JAVA?

[answer to this non-question hopes to try and reduce the noise level of
the recurrent "CGI vs JAVA" threads].
CGI and JAVA are fundamentally different, and for most applications
are NOT interchangable.
CGI is a protocol for running programs on a WWW server.  Whilst JAVA
can also be used for that, and even has a standardised API (the servlet,
which is indeed an alternative to CGI), the major role of JAVA on the
Web is for clientside programming (the applet).
In certain instances the two may be combined in a single application:
for example a JAVA applet to define a region of interest from a
geographical map, together with a CGI script to process a query
for the area defined.