How to remove a websocket mapping

[gabrielandrade2]

Jetty Version
Jetty 12.1.0

Jetty Environment
ee10

Java Version
Eclipse Adoptium OpenJDK 64-Bit Server VM 17.0.14+7;

Question
I have recently upgraded my project from Jetty 9.4 to 12.
One of the features of my system spawns/removes a websocket enpoint whenever the user enables/disables it.

Previously (in Jetty 9.4) the websocket mapping was being removed with the following code snipped without any issues:

ServletContextHandler contextHandler = getContextHandler(webSocket);
if (contextHandler != null) {
    ServletContext servletContext = contextHandler.getServletContext();
    ServerContainer container = (ServerContainer) servletContext.getAttribute(
            ServerContainer.class.getName());
    if (container == null) {
        return;
    }

    if (container instanceof ContainerLifeCycle) {
        ContainerLifeCycle containerLifeCycle = (ContainerLifeCycle) container;
        NativeWebSocketConfiguration configuration = containerLifeCycle.getBean(
                NativeWebSocketConfiguration.class);
        if (configuration != null) {
            configuration.removeMapping("uri-template|" + webSocket.getPath());
        }
    }
}

Upon the migration to Jetty 12, I had to make a few adjustments to have it running, because NativeWebSocketConfiguration is no longer available. Thus, my refactored code looks like the following:

ServletContextHandler contextHandler = getContextHandler(webSocket);
if (contextHandler != null) {
    boolean removed = false;
    WebSocketMappings webSocketMappings = contextHandler.getBean(
            WebSocketMappings.class);
    if (webSocketMappings != null) {
        PathSpec pathSpec = new UriTemplatePathSpec(webSocket.getPath());
        webSocketMappings.removeMapping(pathSpec);
    }
}

This, however, does not work as I'd expect. I can confirm that the mapping is removed (by dumping the running server config), but the rest of the websocket mappings that I have on the same context do not work anymore.

I am using Jakarta rather than Jetty's implementation for the websocket container, and upon exploring a little of the code, I don't see why manually removing the mapping would break other websocket endpoints.

Is there something I am doing wrong? Is there a better way to remove such endpoints at runtime?
(Preferably, I'd like to continue using Jakarta classes, to keep the same standard throughout the project)

[sbordet]

I can confirm that the mapping is removed (by dumping the running server config), but the rest of the websocket mappings that I have on the same context do not work anymore.

What do you mean exactly by "do not work anymore"?
You get an exception?
You get a 404?

[gabrielandrade2]

Sorry for the incomplete information.

Yes, I do get a 404 on a different endpoint, which is not supposed to be removed.
According to the result of the dump() method, that mapping is still on my configuration.

[gabrielandrade2]

I noticed that the websocket mapping fails to be retrieved on WebSocketMappings.getMatchedNegotiator(), more specifically, on the mappings.getMatched(target) call, even though I can confirm that the remaining mappings are still being stored in the mappings object.

I am still trying to understand how everything works and why those are not properly retrieved.

[gabrielandrade2]

@sbordet
Apparently, the issue is being caused by the PathMappings._orderIsSignificant flag.

This boolean variable is set to true when I add my websocket mappings, but it it is set back to false when any of them is removed. The WebSocketMappings.removeMapping() method sets it with the value returned by nonServletPathSpec() (which is false).

I don't fully understand why this flag is important for the search of the websocket mappings, especially because in my case, their order is not really important anyway. I'd expect the mapping match to work regardless of this flag being true or not, so perhaps this is a bug?

I wonder if the return value of nonServletPathSpec() should be inverted.
Currently, nonServletPathSpec() returns true if all mappings are instances of ServletPathSpec. However, by its name, it should return true if there is at least one mapping that is not a ServletPathSpec or if none of them are.

[lachlan-roberts]

I opened PR #13593 to fix this.

[gabrielandrade2]

@lachlan-roberts Thank you very much