How to receive xml as a form parameter

Hi,

In my application I have to receive a xml as a form parameter in the
http request from a third party. And then this xml needs to be parsed
using their sdk. Now the problem is that they don’t have a ruby sdk. So
the only choice I have is to receive the xml in RoR, and pass this to
java apis using JRuby and do the rest of the processing from the output
that I get from java.

Now the problem is that I am a newbie in RoR and need help in getting
the xml out of the http post request and passing it to java using JRuby.
Any help and pointers are really appreciated .

Thanks.