How to get the interpolated message of ValidationException of Hibernate Validator - spring

Question

Running ex.getMessage() gives me:
Property 'firstname' threw exception; nested exception is javax.validation.ValidationException:
Error validating field firstname of class com.inferoquest.entity.Employee:
[ConstraintViolationImpl{interpolatedMessage='Name cannot be shorter than 2 characters',
propertyPath=firstname, rootBeanClass=class com.inferoquest.entity.Employee,
messageTemplate='Name cannot be shorter than 2 characters'}]
from which I'd like to extract Name cannot be shorter than 2 characters.
Update: Maybe I should add also that I'd like to do this in a clean manner, not by regex :-)
I've already seen this thread on the subject. Its answer might contain the solution to me but to be honest I thought it seemed overly complicated for such a simple task and honestly couldn't understand it well enough to use it.
Any ideas?

Answer 1

A ConstraintViolationException wraps a set of ConstraintViolations (see the JavaDoc for more details). You can obtain these violations by invoking getConstraintViolations() on the caught exception, iterate over the set and build a message with all messages of the contained violations.

Answer 2

I would like to add updated solution with Java 8 Steam API.
#ExceptionHandler(ConstraintViolationException.class)
#ResponseStatus(HttpStatus.BAD_REQUEST)
public ResponseEntity<String> handleConstraintViolationException(ConstraintViolationException exception) {
List<String> errorMessages = exception.getConstraintViolations()
.stream()
.map(ConstraintViolation::getMessage)
.collect(Collectors.toList());
return ResponseEntity.badRequest().body(errorMessages.toString());
}
Of course responding with only string is not a good idea, you can use your own custom Response class.

Answer 3

Implementation to the above solution.
#RestControllerAdvice(basePackageClasses = RepositoryRestExceptionHandler.class)
public class GlobalExceptionHandler {
#ExceptionHandler(ConstraintViolationException.class)
public ResponseObject handleConstaintViolatoinException(final ConstraintViolationException ex) {
StringBuilder message = new StringBuilder();
Set<ConstraintViolation<?>> violations = ex.getConstraintViolations();
for (ConstraintViolation<?> violation : violations) {
message.append(violation.getMessage().concat(";"));
}
return new ResponseObject(HttpStatus.PRECONDITION_FAILED.value(), message.toString());
}
}

Answer 4

The easiest way to get only the message from this line is to write in the catch section:
ex.getConstraintViolations().forEach(v -> System.out.println(v.getMessage()));
Search for this solution for about three hours and at least found this.
Of course, if you want to do something more complicated, you need something else. But this is enough for the beginning.