Here it is an example on how Microsoft do that:
http://www.codeproject.com/KB/WCF/WCFVAB.aspx
I was forced to work with .Net technologies last year and despite my
personal preferences I should recognize .Net framework has a
comfortable mechanism for validation...
In Jersey I would say that using annotations would be a natural
choice, something like:
@Validate(param="value", validator="ValidClass.class")
public void operation(int value)
the suggestion to create a type and use it in the service context is
also not bad..
* these are raw observations, suggestions and wish list only..