Custom FrameDecoder

[RakeshPatil111]

Problem / use case

Can I add custom frame decoder for receiving webSocketFrames.

Feature (solution)

This will help to avoice some exceptions.
In my case server side implementation is based on SocketJS so I am unable to decode the frame.
Getting Inavlid Stomp Frame, invalid stomp comman 'o'.
The server is sending text fram with text O.
There is no other endpoint without sockJS.

Current alternatives

No response

[joffrey-bion]

I think what you need is not a custom FrameDecoder (which is about decoding real valid STOMP frames). Instead, you should use a custom WebSocketClient/WebSocketSession to handle the SockJS protocol and convert to web socket frames.

There is already an implementation of SockJS web socket: krossbow-websocket-sockjs. Have you considered using this?

[RakeshPatil111]

Yes I did. But it did not work, faced app crash with NoDefinitionForClass.

[RakeshPatil111]

I think what you need is not a custom FrameDecoder (which is about decoding real valid STOMP frames). Instead, you should use a custom WebSocketClient/WebSocketSession to handle the SockJS protocol and convert to web socket frames.

There is already an implementation of SockJS web socket: krossbow-websocket-sockjs. Have you considered using this?

How I can use custom client or session for this?

[joffrey-bion]

Yes I did. But it did not work, faced app crash with NoDefinitionForClass

I would be very grateful if you could open an issue about this, with the exception you had. I will investigate.

How I can use custom client or session for this?

I mean that you could implement your own implementation of web socket client and session to process the SockJS wrapping and expose them as web socket frames. This is what the SockJS clients that are wrapped in krossbow-websocket-sockjs already do, that's why it might be a bit overkill and it might be worth fixing the issue instead.

[RakeshPatil111]

Yes I did. But it did not work, faced app crash with NoDefinitionForClass

I would be very grateful if you could open an issue about this, with the exception you had. I will investigate.

How I can use custom client or session for this?

I mean that you could implement your own implementation of web socket client and session to process the SockJS wrapping and expose them as web socket frames. This is what the SockJS clients that are wrapped in krossbow-websocket-sockjs already do, that's why it might be a bit overkill and it might be worth fixing the issue instead.

Thanks for reply.
I do get following exception
java.lang.NoClassDefFoundError: Failed resolution of: Ljakarta/websocket/ContainerProvider; at org.springframework.web.socket.client.standard.StandardWebSocketClient.<init>(StandardWebSocketClient.java:75) at org.hildan.krossbow.websocket.sockjs.SockJSClientKt.createDefaultSockJSTransports(SockJSClient.kt:14)
I am using client as below
val stompClient = StompClient(SockJSClient(), StompConfig())

[joffrey-bion]

Ah I think this is the JSR-356 implementation that is missing.

I explained this in the Spring section of the docs, but I forgot to mention it in the SockJS client docs (it uses spring on JVM).

Can you please try providing an implementation like this?

implementation("org.glassfish.tyrus.bundles:tyrus-standalone-client-jdk:2.2.0")

[RakeshPatil111]

Ah I think this is the JSR-356 implementation that is missing.

I explained this in the Spring section of the docs, but I forgot to mention it in the SockJS client docs (it uses spring on JVM).

Can you please try providing an implementation like this?

implementation("org.glassfish.tyrus.bundles:tyrus-standalone-client-jdk:2.2.0")

Thanks, I did found it and added, but still facing issue,
Initial SockJS "Info" request to server failed, org.springframework.web.client.HttpClientErrorException$NotFound: 404 : [no body]

Without SockJSClient, I face InvalideStompFrameException. May be need to make some changes at server end.

[joffrey-bion]

Sorry for the delay. Did you figure it out eventually? 404 seems like you're not calling the right endpoint on your server. Did you check that?

[RakeshPatil111]

Sorry for the delay. Did you figure it out eventually? 404 seems like you're not calling the right endpoint on your server. Did you check that?

Yes I did check, resolved 404 issue. But currently facing issue related with frame formats, frame sent from client(mobile) are not read by server. Possible reason end characters.(\u0000,\n etc)