From: Jeremy Bopp <jeremy@...>
Date: 2010-10-07T04:43:25+09:00
Subject: Re: XML-RPC WEBrick problem (error during method invocation)

On 10/6/2010 5:13 AM, Nikita Kuznetsov wrote:
> I have a university assignement, and i am stuck. I am supposed to create
> a server using xml-rpc with ruby, but I keep getting errors. I am not
> very good with ruby, this is actually the first time im working on a
> ruby assignement.
> The goal is to in the end create 3 client/server programs in 3 different
> languages:ruby,c# and java and to have them communicate. sadly i cant
> even get it to communicate from ruby to ruby.
> 
> here is my server :
> require 'webrick'
> require 'xmlrpc/server.rb'
> 
> class Something<XMLRPC::WEBrickServlet
> 
> def initialise()
> # create a servlet to handle XML-RPC requests:
> servlet = XMLRPC::WEBrickServlet.new
> servlet.add_handler("upper_case") { |a_string| a_string.upcase }
> servlet.add_handler("help"){|| puts "print some string"}
> servlet.add_handler("lower_case") { |a_string| a_string.downcase }
> 
> # create a WEBrick instance to host this servlet:
> server=WEBrick::HTTPServer.new(:Port => 9090)
> trap("INT"){ server.shutdown }
> server.mount("/RPC2", servlet)
> 
> server.start
> end

The server code is incomplete.  I managed to get something to work and
reproduce your problem with a little editing though.  Take care to be as
accurate as possible when asking for help with code. ;-)

> here is my client:
> require 'xmlrpc/client'
> server = XMLRPC::Client.new("127.0.0.1", "/RPC2", 9090)
> 
> puts server.call("upper_case", "abcd")
> puts server.call("lower_case", "HELLO")
> server.call("help")
> 
> the calls for upper and lower case work fine, but if i want to just puts
> a string on the screen, it doesnt seem to work.
>
> C:\Users\Moog\Ruby>xmlclient.rb
> ABCD
> hello
> C:/Ruby192/lib/ruby/1.9.1/xmlrpc/client.rb:549:in `do_rpc': HTTP-Error:
> 500 Inte
> rnal Server Error  (RuntimeError)
>         from C:/Ruby192/lib/ruby/1.9.1/xmlrpc/client.rb:420:in `call2'
>         from C:/Ruby192/lib/ruby/1.9.1/xmlrpc/client.rb:410:in `call'
>         from C:/Users/Moog/Ruby/xmlclient.rb:6:in `<main>'
> 
> I am completely stuck on this. All help would be greatly appreciated.

Since this is a school assignment, I'll only say that you're very close
to the solution and suggest that you closely watch the output of your
server while you run your client.

Good luck!

-Jeremy