need to get the actual request body content from WebRequest while overriding handleMethodArgumentNotValid method in ResponseEntityExceptionHandler

Question

I want the request body content from WebRequest when I override the below method in my ExceptionHandler which extends ResponseEntityExceptionHandler.

protected org.springframework.http.ResponseEntity<java.lang.Object> handleMethodArgumentNotValid(
    org.springframework.web.bind.MethodArgumentNotValidException ex, 
    org.springframework.http.HttpHeaders headers,
    org.springframework.http.HttpStatus status,
    org.springframework.web.context.request.WebRequest request) { 
/* compiled code */ }

I was able to cast WebRequest to ServletWebRequest like this ((ServletWebRequest)request) and calling getRequest() method to return the HttpServletRequest.
But I am not able to get the content from ContentCachingRequestWrapper, its giving blank string or 0 bytes. Please help me on this.

ContentCachingRequestWrapper wrapperRequest = 
      new ContentCachingRequestWrapper(((ServletWebRequest)request).getRequest());