@Future
private Date shippingDate;

public class MyFutureValidator implements ConstraintValidator<Future, Date> {

    public void initialize(Future constraintAnnotation) {}

    public boolean isValid(Date value, ConstraintValidatorContext context) {

        Date now = ...;

        if( value.after( now ) ) {

            context.disableDefaultConstraintViolation();
            context
                .buildConstraintViolationWithTemplate("Must be after {now}")
                .setValue( "now", now )
                .addConstraintViolation();

            return false;
        }

        return true;
    }
}