Using Spring's MessageSource for setting FieldError default messages

Question

After my form backing object is validated I have a BindingResult, which contains a list of FieldError. Each FieldError has a defaultMessage. How is that message set and why doesn't it use my Spring MessageSource? I would like that default message to be derived from my Spring's MessageSource.

EDIT: I see that the error codes are being set correctly in the FieldError object. It's just the default message in that object is not coming from my MessageSource. For instance, when I enter a string for a field that is an int I want it to get my message from messages.properties:

typeMismatch=Invalid type was entered.

The only way I can get that message is if I take my FieldError object and pass it into the MessageSource manually like so:

messageSource.getMessage(fieldError, null);  // This gets my message from messages.properties.

Answer 1

If you're using a Validator, you can specify the keys for the messages in the MessageSource in the Validator implementing class, usually using ValidationUtils methods. Section 6.2 of the Spring documentation has a good example.

Spring will also try to resolve error codes by convention if you're using something other than a Validator like JSR-303 Bean Validation.

Let's say you had a form backing object called 'Address' with an int field called 'zipcode.' If the user entered a string for the zipcode field, by default Spring will use the DefaultMessageCodesResolver and look in the MessageSource for a key called 'typeMismatch.address.zipcode.' If it doesn't find that key, it will try 'typeMismatch.zipcode,' then 'typeMismatch.int,' then 'typeMismatch.'

Or, you can implement your own MessageCodesResolver.