spring-security - Vaadin：Drop 组件的 Spring 上下文是什么？

Question

我正在使用 21 版本的 Vaadin。我有以下代码，取自 Vaadin 网站的一个示例，并由我稍微（纯粹是美丽）修改。其余文件不变。

代码如下。为什么我会得到这样的日志？

2022-01-20 10:08:32.589 DEBUG 12556 --- [nio-8888-exec-6] cephotoarchive.components.DropView：放置 1. 用户在这里 2022-01-20 10:08:38.197 TRACE 12556 --- [nio-8888-exec-1] c.example.photoarchive.SecurityService：身份验证为空 2022-01-20 10:08:38.197 DEBUG 12556 --- [nio-8888-exec-1] cephotoarchive.components.DropView ：将 2. 用户放在这里 <>

@Log4j2
@Route(value = "drop", layout = MainAppLayout.class)
public class DropView extends VerticalLayout implements HasComponents {
    private final SecurityService securityService;

    public DropView(SecurityService securityService) {
        this.securityService = securityService;

        MultiFileMemoryBuffer buffer = new MultiFileMemoryBuffer();
        Upload upload = new Upload(buffer);
        upload.setUploadButton(new Button(getTranslation("Upload_files")));
        upload.setDropLabel(new Label(getTranslation("Drop_files")));
        upload.setMaxFileSize(-1);

        log.debug("Place 1. User here <{}>", getUsername());

        upload.addFinishedListener(e -> {
            log.debug("Place 2. User here <{}>", getUsername());
            // my code ... too much :-)
        });
        add(upload);
    }

    private String getUsername() {
        var user = securityService.getAuthenticatedUser();
        if (user != null) return user.getUsername();
        return "";
    }
}


@Log4j2
@Service
public class SecurityService {
    private static final String LOGOUT_SUCCESS_URL = "/";

    public UserDetails getAuthenticatedUser() {
        SecurityContext context = SecurityContextHolder.getContext();
        if (Objects.isNull(context)) {log.trace("context is null");return null;}

        Authentication authentication = context.getAuthentication();
        if (Objects.isNull(authentication)) {log.trace("authentication is null");return null;}

        Object principal = authentication.getPrincipal();
        if (Objects.isNull(principal)) {log.trace("principal is null");return null;}

        if (principal instanceof UserDetails) {
            return (UserDetails) principal;
        }
        // Anonymous or no authentication.
        return null;
    }
}