I cannot connect to the websocket using Postman

Question

I am trying to create a simple chat application using websockets. I followed this tutorial: https://www.baeldung.com/websockets-spring.

This is my config:

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

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

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
         registry.addEndpoint("/chat");
         registry.addEndpoint("/chat").withSockJS();
    }
}

@Controller
public class WebSocketController {
    @MessageMapping("/chat")
    @SendTo("/topic/messages")
    public OutputMessage send(Message message) throws Exception {
        return new OutputMessage(message.getFrom(), message.getText(), Instant.now());
    }
}

@Builder
@Getter
public class Message {
    private final String from;
    private final String text;
}

@Builder
@Getter
public class OutputMessage {
    private final String from;
    private final String text;
    private final Instant date;
}

At the start of the application I got:

2021-12-31 14:22:39.442  INFO 1952 --- [MessageBroker-1] o.s.w.s.c.WebSocketMessageBrokerStats    : WebSocketSession[0 current WS(0)-HttpStream(0)-HttpPoll(0), 0 total, 0 closed abnormally (0 connect failure, 0 send limit, 0 transport error)], stompSubProtocol[processed CONNECT(0)-CONNECTED(0)-DISCONNECT(0)], stompBrokerRelay[null], inboundChannel[pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0], outboundChannel[pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0], sockJsScheduler[pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 0]

I thought I had everything configured so I decided to try to connect using postman, but without success :/ I executed the following endpoints:

ws://localhost/app/chat
ws://localhost:8080/app/chat
ws://localhost/chat
ws://localhost:8080/chat

none of them work :/

I am using Postman Websockets beta to perform requests.

Did I miss something in the configuration or am I using postaman wrong?

Answer 1

According to the reply from Postman Team in their blog: https://blog.postman.com/postman-supports-websocket-apis/ . Postman does not support subscribe to a topic at present. So in this case, you can only connect to server with 'ws://localhost:8080/chat', but you can not send messages between web client and server. What a pity!

Answer 2

- registry.addEndpoint("/chat").withSockJS();

+ registry.addEndpoint("/chat");

It works for me.