After reading the JSR-303 and starting to write our own constraints we came to the point where we would like to add custom reason codes / error codes on constraints.
Example: If a zip code does not validate properly our system should always assign the error code "1234" to the error being added.

We considered several options but did not manage to find a proper solution yet:
- context.addError would be the optimal place during validation, but the interface is limited to message and property
- adding a constraint property "errorCode() default=1234" would be an option, but how to access it after validation? Needs reflection :-/
- adding an annotation "@ErrorCode(code=1234)" to the constraint would be an option

Of course we may have overlooked a possibility. If you happen to find a minute to give us a short advice on this we would be very happy.

Note: The error code should clearly be another thing than the error message (altough it could be a 1:1 mapping). This is the requirement we got, so we can't argue about this.

What's about using the payload parameter. If I understand correctly you want to pass information (error code) through the system without really modifying/using it. That's what payload is for and that's the reason why every constraints has to define one.

You could have payload classes for each error type. The specification does contain an example were the payload is used to pass the severity of a constraint along. The online documentation is unfortunately still missing this section.

The code could look like this:


where Error is defined as:


--Hardy