Spring ExceptionHandler access to Model? - spring-mvc

Question

I have a spring controller which uses bean validation to validate input values, for example to save a topic:
public String save(#ModelAttribute("topic") #Valid Topic topic
This works nicely.
In my data layer i also use bean validation and when something invalid is send to the data layer a ConstraintViolationException is thrown. I catch this one in my controller with a exceptionhandler:
#ExceptionHandler({ ConstraintViolationException.class })
public ModelAndView handleValidationException(HttpServletRequest req,ConstraintViolationException e) {
This also works nicely.
The problem i'm facing is i can't access the model in my exceptionhandler, the docs clearly states this:
Important Note: the Model may not be a parameter of any #ExceptionHandler method.
Access to the model is needed cause i want to show the user the view with the form he just filled in. But because i can't access the model i can't get the filled out form data.
One solution i found is catching the ConstraintViolationException in my save() method, cause here i do have access to the model.
But i would prefer a generic solution and not have messy try/catch/finally when i need to save something to the database.
Does anybody know a good solution?
[edit]
Here's my current exception handler:
#ExceptionHandler({ ConstraintViolationException.class })
public ModelAndView handleValidationException(HttpServletRequest req,ConstraintViolationException e) {
log.debug("handleValidationException");
//no access to model, so i create new one, but this new one doesn't have the values the user entered in the html form.
ModelAndView mav = new ModelAndView();
mav.addObject("exception", e);
mav.setViewName("add_topc");
return mav;
}

Answer 1

After some thoughts on this subject i came to the conclusion that a single error page displaying a error is enough. Mainly because the errors thrown by the data layer are fatal errors that can't be corrected by the user, for example by changing field values. It of course would have been nice to display the error page in the context of where things did go wrong and save the users input. But that doesn't seem to be possible with spring.

Answer 2

A bit old but I found myself in a similar situation.
One possible solution would be to wrap the model in the contraintViolationException such that the exception handler could pull the model from the exception.
I haven't found any good explanation of why the model is cleared/not available in the exception handler - except someone who hypothesized that it was by design as the model could be in an invalid state.
SNIPET from Controller
...
throw new ConstraintViolationException(model);
SNIPET from ModelAwareException
public void ConstraintViolationException(Model saveModel) {
this.model = saveModel;
}
SNIPET from ExceptionHandler
#ExceptionHandler({ ConstraintViolationException.class })
public ModelAndView handleValidationException(HttpServletRequest req,ConstraintViolationException e, Model unpopulatedSpringModel) {
unpopulatedSpringModel = e.getModel();
return new ModelAndView("yourpage");
}