Web Socket endpoints

Question

Hello everyone I'm having some issues figuring out some websocket endpoints. I am trying to build a basic chat application to help me gain an understanding of websockets.

I'm running a Java 8 Spring Boot Websocket server that is running on http://localhost:8080 for testing purposes.

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketMessageConfig implements WebSocketMessageBrokerConfigurer {


    @Override
    public void registerStompEndpoints(final StompEndpointRegistry registry) {
        WebSocketMessageBrokerConfigurer.super.registerStompEndpoints(registry);
        registry.addEndpoint("/websocket").setAllowedOriginPatterns("*").withSockJS();
    }

    @Override
    public void configureMessageBroker(final MessageBrokerRegistry registry) {
        WebSocketMessageBrokerConfigurer.super.configureMessageBroker(registry);
        registry.setApplicationDestinationPrefixes("/app");
        registry.enableSimpleBroker("/topic");
    }
}

@Controller
public class SocketController {



    @MessageMapping("/socket.send")
    @SendTo("/topic/public")
    public SocketMessage sendMessage(@Payload final SocketMessage message) {
        return message;
    }

    @MessageMapping("/socket.newUser")
    @SendTo("/topic/public")
    public SocketMessage newUser(@Payload final SocketMessage message,
                                 SimpMessageHeaderAccessor  headerAccessor) {

        headerAccessor.getSessionAttributes().put("username", message.getSender());
    return message;
    }

}

That's my config file and controller file... My understanding is that the registerStompEndpoints() is giving the endpoint to setup the connection between client/server for a session.

The front end request will look like

That seems to work fine from my javascript front end request. I see a good log showing a connection to that, but when I try to send a newUser or a message, neither appear to be properly going to the server. I don't see anything in the logs so I suspect my endpoints from the front-end are incorrect...

const socket = new SockJS('http://localhost:8080/websocket')
stompClient.subscribe('http://localhost:8080/topic/public', onMessageReceived)
stompClient.send("http://localhost:8080/app/socket.newUser",
stompClient.send("http://localhost:8080/app/socket.send", {}, JSON.stringify(chatMessage))

This is my console.log from the from the front end

>>> SUBSCRIBE
id:sub-0
destination:http://localhost:8080/app/topic/public

>>> SEND
destination:http://localhost:8080/app/socket.newUser
content-length:36

{"sender":"testname","type":"CONNECT"}

The idea is that you set up the websocket connection, and then you communicate directly through that. So you don't send things by using URLs; once established the web socket has no idea what a URL is. Also, all modern browsers have native websocket support, no need for SockJS, just create a [normal client-side WebSocket connection](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_client_applications) — Mike 'Pomax' Kamermans, Aug 26 '22 at 15:39
Thank you for that suggestion. I made the changes and it is now properly working. Credit to you for the answer! — Justin Garner, Aug 26 '22 at 16:02

score 0 · Answer 1 · answered Aug 26 '22 at 16:05

Thanks to Mike 'Pomax' Kamermans for the solution.

My error was in my front end code.

This was my original setup.

const socket = new SockJS('http://localhost:8080/websocket')
stompClient.subscribe('http://localhost:8080/topic/public', onMessageReceived)
stompClient.send("http://localhost:8080/app/socket.newUser",
stompClient.send("http://localhost:8080/app/socket.send", {}, JSON.stringify(chatMessage))

It was changed to look like ....

const socket = new SockJS('http://localhost:8080/websocket')

stompClient.subscribe('/topic/public', onMessageReceived)

stompClient.send("/app/socket.newUser",

stompClient.send("/app/socket.send", {}, JSON.stringify(chatMessage))```


This was the cause of my issues. Thanks for the help!

If this is the correct answer please mark it as such so it's clear to others who have this same question in the future. Thanks! — Justin Bertram, Aug 27 '22 at 17:02

Web Socket endpoints

1 Answers1