Is there a way to add custom validations? The JSR 303 / 380 only allow s

Directory Crud UI Add-on
1

Is there a way to add custom validations? The JSR 303 / 380 only allow single value validation and I need a date start <= date end validation. Throwing an IllegalArgumentException from the setter is not working (it is not displayed).

2 
		VaadinSession.getCurrent().setErrorHandler((ErrorHandler) event -> {
			Throwable t = event.getThrowable();
			while (t.getCause() != null ) {
				t = t.getCause();
			}
			showErrorNotification(t.getMessage());
			if (LOG.isInfoEnabled()) LOG.info(t.getMessage(), event.getThrowable());
		});


3

In theory you should be able to implement a custom validator and constraint annotation and use it in your Entities. Did you find any blockers to this approach?