Spring 1.2.3

I am trying to figure out how to display a user-friendly message when an exception is thrown from my command object on binding. I have already figured out how to display user-friendly messages when validation fails. That is not the issue. Here's a little more detail.

My setter throws an exception if a certain business rule fails. But when the form is re-displayed, I get an ugly message like this: Property startDate threw exception; nested exception is com.bennettsworld.careermanager.exceptions.StartDa teLaterThanEndDateException: Start date must be earlier than the end date.

How can I tie this into my ResourceBundleMessageSource? This is not a typeMismatch or required message. This is a business rule message. So I'm a little confused as to how this is done.

Any tips you can provide are greatly appreciated. Thank you in advance.