Annotated form validation - conversion failed custom message

Question

I'm analyzing spring-mvc-showcase example project (spring-mvc-showcase github). Confused with the way validation response is presented on JSP page when I hit incorrect date format (Birth Date field on screenshot). How can I make it more user friendly with some custom message, without those ConversionFailedException details?

screenshot:

Annotation-driven validation is applied. Down below is code segment from bean class representing birthDate field.

FormBean.java

@DateTimeFormat(iso=ISO.DATE)
@Past
private Date birthDate;

Method responsible for form submit:

FormController.java

@RequestMapping(method=RequestMethod.POST)
public String processSubmit(@Valid FormBean formBean, BindingResult result, 
                            @ModelAttribute("ajaxRequest") boolean ajaxRequest, 
                            Model model, RedirectAttributes redirectAttrs) {
    if (result.hasErrors()) {
        return null;
    }
    // Typically you would save to a db and clear the "form" attribute from the session 
    // via SessionStatus.setCompleted(). For the demo we leave it in the session.
    String message = "Form submitted successfully.  Bound " + formBean;
    // Success response handling
    if (ajaxRequest) {
        // prepare model for rendering success message in this request
        model.addAttribute("message", message);
        return null;
    } else {
        // store a success message for rendering on the next request after redirect
        // redirect back to the form to render the success message along with newly bound values
        redirectAttrs.addFlashAttribute("message", message);
        return "redirect:/form";            
    }
}

Answer 1

Note, that you are working with binding errors here. These are thrown long before the actual JSR-303 validation is performed and they override JSR-303 constraint violations for the failed field.

Codes for the binding errors are typeMismatch. So you can add for example this to your messages properties:

typeMismatch.birthDate = Invalid birth date format.

Check JavaDoc for DefaultMessageCodesResolver and DefaultBindingErrorProcessor to discover how Spring's error code resolution works.