@Override public Response toResponse(MethodConstraintViolationException ex) { Map<String, String> errors = new HashMap<String, String>(); for (MethodConstraintViolation<?> methodConstraintViolation : ex.getConstraintViolations()) { errors.put( methodConstraintViolation.getParameterName(), methodConstraintViolation.getMessage()); } return Response.status(Status.PRECONDITION_FAILED).entity(errors).build(); }