Assuming you meant 'module A', the first defines an instance method, the second a module method. The instance method cannot be called until the module is mixed in to a class using 'include'. The module method can be called by giving the module name as a receiver:

instance method 只有在被 mixed 的時候才有用

A quick browse through the servlet examples, along with the RDoc gets us well on the way. We will start our server on port 8000, and mount two 'paths' - one for serving the survey, and second for processing the POST request (saving the form):

> webrick-init.rb

require 'rubygems'
require 'webrick'
require 'dbi'
 
# Initialize our WEBrick server
if $0 == __FILE__ then
  server = WEBrick::HTTPServer.new(:Port => 8000)
  server.mount "/questions", WebForm
  server.mount "/save", PersistAnswers
  trap "INT" do server.shutdown end
  server.start
end