Как установить имя пользователя для подключения к веб-сокету в Backend в приложении Spring?

Question

Я создал приложение Spring со следующей структурой кода:
SocketConfig. java

@Configuration
@EnableWebSocketMessageBroker
public class SocketConfig extends AbstractWebSocketMessageBrokerConfigurer{ //implements WebSocketMessageBrokerConfigurer {

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.setApplicationDestinationPrefixes("/app").enableSimpleBroker("/queue", "/topic");
//        config.setUserDestinationPrefix("/user");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
//        registry.addEndpoint("/questions").setHandshakeHandler(new CustomHandshakeHandler()).withSockJS();
        registry.addEndpoint("/questions").setHandshakeHandler(new CustomHandshakeHandler()).withSockJS();
    }
}

CustomHandshakeHandler. java

public class CustomHandshakeHandler extends DefaultHandshakeHandler {
    // Custom class for storing principal
    @Override
    protected Principal determineUser(ServerHttpRequest request, WebSocketHandler wsHandler,Map<String, Object> attributes) {
        // Generate principal with UUID as name
        String uuid = UUID.randomUUID().toString();
        try {
            UserStorage.getInstance().setUser(uuid);
        } catch (Exception e) {
            System.out.println("Error while creating user: " + uuid);
        }
        return new UsernamePasswordAuthenticationToken(uuid, null);
    };

}

SocketController. java

@Controller
public class SocketController {

    @Autowired
    private SimpMessagingTemplate simpMessagingTemplate;
    private static final Logger log = LoggerFactory.getLogger(SocketController.class);

    /**
     * Example of sending message to specific user using 'convertAndSendToUser()' and '/queue'
     */
    @MessageMapping("/questions")
    public String sendSpecific(String question,Principal user) throws Exception {
        return question.toUpperCase();

    }
}

коннектор. js

var stompClient = null;

function connect() {
     var socket = new SockJS('/questions');
     stompClient = Stomp.over(socket);
//     $.ajax({
//        url:'/connectMe',
//        dataType:'json',
//     });
    stompClient.connect({}, function (frame) {
        stompClient.subscribe("/topic/questions", function (response) {
            console.log(JSON.parse(response.body).content);
        });
    });
}

function sendMessage() {
    stompClient.send("/app/questions", {}, JSON.stringify({'message': $("#message").val()}));
}

function showMessage(message) {
    $("#greetings").append("<tr><td>" + message + "</td></tr>");
}

$(function () {
    connect();
    $("form").on('submit', function (e) {
        e.preventDefault();
    });
    $( "#send" ).click(function() { sendMessage(); });
});

пом. xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.random-chat-app</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.security/spring-security-core -->
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-core</artifactId>
            <version>4.2.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-reactor-netty</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-websocket</artifactId>
            <version>8.0.28</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>bootstrap</artifactId>
            <version>3.3.7-1</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.5.1</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>sockjs-client</artifactId>
            <version>1.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>stomp-websocket</artifactId>
            <version>2.3.3</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Но я не могу увидеть данные пользователя, которые у меня были установлен в CustomHandshakeHandler в объекте пользователя в функции sendSpecifi c в контроллере. Кто-нибудь может сказать мне, почему это происходит?