问如何使用spring web套接字向特定登录用户发送消息

EN

import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/chatWS") // ws connection url
        .setAllowedOrigins("*")
        .withSockJS();
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
         registry.setApplicationDestinationPrefixes("/app")// to send data to ws
         .enableSimpleBroker("/topic"); // to subscribe for real time feed
    }

}