You are absolutely not rong, sorry, wrong.
That is what is happening. You post the fields in a query
string to the Servlet that answers on the
pattern /GreetingServlet. It then processes the request, like looking for the mandatory name fields.
I don't know how the rest of your Servlet class post-method looks like. But that should work. If you change the action url, then you also need to change or add the mapping to the servlet so that it knows that it is supposed to react on the call.
And one little thing... try to use positive programing.
The code:
should, imho, be rewritten as