Get JAX-RS POST parameter in Interceptor

[New Groovy]

Hi,

I have a method that receives a POST-ed parameter, so as such, it is not a
path/query param etc.

I need to access it in an In-Interceptor, but am struggling to retrieve
it.  I get the path/query ones from the UriInfo object, but can't figure
out how to get the unnamed one.

Would appreciate some pointers.

Thanks!