Your parameter should either be a
@RequestParam, or a
@RequestBody, not both.
@RequestBody is for use with POST and PUT requests, where the body of the request is what you want to parse.
@RequestParam is for named parameters, either on the URL or as a multipart form submission.
So you need to decide which one you need. Do you really want to have your JSON as a request parameter? This isn’t normally how AJAX works, it’s normally sent as the request body.
Try removing the
@RequestParam and see if that works. If not, and you really are posting the JSON as a request parameter, then Spring won’t help you process that without additional plumbing (see Customizing WebDataBinder initialization).