BeanValidationBinder and Domain class with Optional in getter

Vaadin 6 / 7 / 8
1

If domain class contain getter with Optional type of returned value:

  public Optional<String> getName() {
    return Optional.ofNullable(name);
  }

And use BeanValidationBinder :

BeanValidationBinder<Employee> binder = new BeanValidationBinder<>(Employee.class);
binder.forField(name).withValidationStatusHandler(new BindingValidationStatusHandler() {
      private static final long serialVersionUID = 1L;
      @Override
      public void statusChange(BindingValidationStatus<?> statusChange) {
        if (statusChange.getMessage().isPresent()) {
          name.setComponentError(new UserError(statusChange.getMessage().get()));
        } else {
          name.setComponentError(null);
        }
      }
    })
    .bind("name");

After data input in field appear error:
…
Caused by: java.lang.ClassCastException: Cannot cast java.lang.String to java.util.Optional
…

Source code to reproduce error:

https://github.com/zesetup/vaadin8binder.git