Spring integration (IntegrationFlowContext): Dynamically registering new paths to same websocket server

Question

I was trying to implement spring websocket solution with JavaDsl by following the link i.e https://github.com/joshlong/techtips/tree/master/examples/spring-integration-4.1-websockets-example

And I successfully tested it by subscribing to the path(i.e /messages) with my stomp client.

Next, I tried the same thing by registering the integration flow with IntegrationFlowContext.

It executed successfully on the server-side, but when I tried to make a request by my stomp client I received an exception of 404 not found.

While going through the logs , i found that previously the "AbstractHandlerMapping" was mapping to SockJsHttpRequestHandler and now it is mapping to ResourceHttpRequestHandler

With Spring-managed integration flow (Successful)

DEBUG [http-nio-8081-exec-1] o.s.c.l.LogFormatUtils: GET "/messages/websocket", parameters={}
DEBUG [http-nio-8081-exec-1] o.s.w.s.h.AbstractHandlerMapping: Mapped to org.springframework.web.socket.sockjs.support.SockJsHttpRequestHandler@46185a1b
DEBUG [http-nio-8081-exec-1] o.s.w.s.s.s.AbstractSockJsService: Processing transport request: GET http://localhost:8081/messages/websocket
DEBUG [http-nio-8081-exec-1] o.s.w.s.FrameworkServlet: Completed 101 SWITCHING_PROTOCOLS
DEBUG [http-nio-8081-exec-1] o.s.w.s.h.LoggingWebSocketHandlerDecorator: New StandardWebSocketSession[id=e11b5ef5-d2e5-e5c7-819d-493f42f4a7c8, uri=ws://localhost:8081/messages/websocket]

And with IntegrationFlow context managed flow (Failure)

DEBUG [http-nio-8081-exec-1] o.s.c.l.LogFormatUtils: GET "/messages/websocket", parameters={}
DEBUG [http-nio-8081-exec-1] o.s.w.s.h.AbstractHandlerMapping: Mapped to ResourceHttpRequestHandler ["classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/", "/"]
DEBUG [http-nio-8081-exec-1] o.s.w.s.r.ResourceHttpRequestHandler: Resource not found
DEBUG [http-nio-8081-exec-1] o.s.w.s.FrameworkServlet: Completed 404 NOT_FOUND
DEBUG [http-nio-8081-exec-1] o.s.c.l.LogFormatUtils: "ERROR" dispatch for GET "/error", parameters={}
DEBUG [http-nio-8081-exec-1] o.s.w.s.h.AbstractHandlerMapping: Mapped to org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController#error(HttpServletRequest)
DEBUG [http-nio-8081-exec-1] o.s.w.s.m.m.a.AbstractMessageConverterMethodProcessor: Using 'application/json', given [*/*] and supported [application/json, application/*+json, application/json, application/*+json]
DEBUG [http-nio-8081-exec-1] o.s.c.l.LogFormatUtils: Writing [{timestamp=Tue Feb 25 17:06:58 IST

Please, consider to make your post readable: stackoverflow.com/editing-help. And what is the question so? How to register WebSocket server at runtime? Do you really think it possible and such a behavior has a value in the real life? Who's going to connect to such a dynamically created server? The client definitely has to know where to connect using statically declared URL somewhere. — Artem Bilan
Hey, I changed the post to make it more readable now. I just wanted to register multiple paths(like /topic1,/topic2,etc) on the newly created wesocket server. Please let me know if it is possible. — Dhiraj Singh
OK. That's bad you have remove code snippets. That would fulfill a picture. Anyway you don't describe a reason of creating a WebSocket server and registering those mappings at runtime... — Artem Bilan
I was just experimenting with websocket example, there is no specific use case that I have thought of. — Dhiraj Singh

Artem Bilan Artem Bilan · Accepted Answer · 2020-02-26T19:43:39

You have a different Mapped to ... because of getHandler(HttpServletRequest request) logic in the AbstractHandlerMapping:

Object handler = getHandlerInternal(request);
    if (handler == null) {
        handler = getDefaultHandler();
    }
    if (handler == null) {
        return null;
    }
    // Bean name or resolved handler?
    if (handler instanceof String) {
        String handlerName = (String) handler;
        handler = obtainApplicationContext().getBean(handlerName);
    }

    HandlerExecutionChain executionChain = getHandlerExecutionChain(handler, request);

    if (logger.isTraceEnabled()) {
        logger.trace("Mapped to " + handler);
    }

We don't support dynamic WS endpoints because we don't scan them in the internal WebSocketHandlerMappingFactoryBean.

Feel free to raise a GH issue https://github.com/spring-projects/spring-integration/issues and we will take a look what we can do for that.

Spring integration (IntegrationFlowContext): Dynamically registering new paths to same websocket server

1 Answers