Bean Validation constraint(s) violated while executing Automatic Bean Validation on callback event:'prePersist'

I got the same problem, but after hours looking for the answer, Finally I Found it.... You should edit your AbstractFacade.java class and add this code

public void create(T entity) {

    ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
    Validator validator = factory.getValidator();
    Set<ConstraintViolation<T>> constraintViolations = validator.validate(entity);
    if(constraintViolations.size() > 0){
        Iterator<ConstraintViolation<T>> iterator = constraintViolations.iterator();
        while(iterator.hasNext()){
            ConstraintViolation<T> cv = iterator.next();
            System.err.println(cv.getRootBeanClass().getName()+"."+cv.getPropertyPath() + " " +cv.getMessage());

            JsfUtil.addErrorMessage(cv.getRootBeanClass().getSimpleName()+"."+cv.getPropertyPath() + " " +cv.getMessage());
        }
    }else{
        getEntityManager().persist(entity);
    }
}

Now this method will alert you which property and why it fails the validation. I hope this works for you, as it does for me.

I got a shortcut way,Catch the following exception where you persisting the entity. In my case its in the EJB add method. where I am doing em.persist(). Then check the server log, you will see which attribute having constrain violation.

catch (ConstraintViolationException e) {
       log.log(Level.SEVERE,"Exception: ");
       e.getConstraintViolations().forEach(err->log.log(Level.SEVERE,err.toString()));
    }

The error displays that the entity you are trying to persist is failing database constraints, so try determining the exact values you are inserting into the database before you actually insert.

and try out by commenting/ommitting @NotNull annotation also.