Отправка сообщения всем клиентам websocket

public class WebSocketHandler extends AbstractWebSocketHandler {
 
    private static WebSocketHandler webSocketHandler;
    private MessageRepo messageRepo;
    private JsonAdapter<Message> adapter;
 
    public WebSocketHandler(MessageRepo messageRepo) {
        this.messageRepo = messageRepo;
 
        Moshi moshi = new Moshi.Builder()
                .add(new DataAdapter())
                .build();
        adapter = moshi.adapter(Message.class);
    }
 
    public static WebSocketHandler getWebSocketHandler(MessageRepo messageRepo)
    {
        if (webSocketHandler == null)
        {
           webSocketHandler = new WebSocketHandler(messageRepo);
        }
        return webSocketHandler;
    }
 
    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        Message messagePayload = adapter.fromJson(message.getPayload());
        messagePayload.setDateTime(LocalDateTime.now());
        messageRepo.save(messagePayload);
        session.sendMessage(new TextMessage(adapter.toJson(messagePayload)));
    }
 
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        session.sendMessage(new TextMessage(exception.getMessage()));
    }
}

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
 
    private final MessageRepo messageRepo;
 
    @Autowired
    public WebSocketConfig(MessageRepo messageRepo) {
        this.messageRepo = messageRepo;
    }
 
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(WebSocketHandler.getWebSocketHandler(messageRepo),"/messages-update");
    }
}