If you have a POST request in SoapUI (in ReadyAPI), the only way I can see to specify that the parameters go in the body, rather than in the URL, is to check the "Post QueryString" checkbox.
But if you do so, the Media Type gets locked to "application/x-www-form-urlencoded"
You can specify "application/json" as the media type if you don't check the box, but then the parameters are sent in the URL, not the POST body.
Also, you can override the Header using the Headers tab down at the bottom of the request editor, but that only overrides the header. It doesn't cause the parameters to be encoded as JSON.
Is there any way to get SOAPUI to do this? My application expects the parameters in the POST body, as a JSON object.