websocket-api | Jakarta WebSocket - | Websocket library

You need to have two separate runs of Maven:

1. Update the version with the versions maven plugin on command line.
2. Run something like mvn clean verify to build the project.

You cannot change the version while building the project.

BTW: You configured Java 5. Are you really sure you want this?

You have most likely forgotten to deploy your API (Routes -> Actions -> Deploy API). WebSocket APIs still use the old console which does not have auto deploy.

It works when I try it

Having the same class name in multiple locations on your classpath is a bad idea.

This is the most common form of unstable operation on Java there is!

The classloaders in Java have no guarantee of load order behavior if the same class is present in multiple locations within the classloader.

In one run you might accidentally load the classes in the order you intend, and have it run properly, then at a future date you run the same program and the load order is different, now you are running with a different class version and you have unexpected behavior.

The only way to fix this is to clean up your classloader and ensure that you only have 1 version of the class you intend to use.

This is what Jetty is telling you.

As for this specific one, javax.websocket-api and javax.websocket-client-api, you want to exclude javax.websocket-client-api at the gradle level, as all of the websocket client classes are also present in the javax.websocket-api.

The javax.websocket-client-api jar is only intended for projects that only use the javax.websocket Client, without a javax.websocket Server.

Following the suggestion of joakim-erdfelt I have modified my gradle.build and this prevent the problem:

I "solved" this by base64 encoding my binary data and using the $default handler, which allows arbitrary datatypes

Could you try with a clean ~/.m2/repository/ (just move yours away before trying)?

It seems like you're setting 1 lambda to handle 2 trigger sources, one is IoT service, the other is API Gateway Websocket. Since you use 1 lambda, you have to handle cases when the request is came from sources:

1. While event.requestContext is available when the request is triggered from API Gateway, it is not available when the request is triggered from IoT service (check the IoT event object here https://docs.aws.amazon.com/lambda/latest/dg/services-iotevents.html). So the error you faced (which is Cannot read property 'domainName' of undefined") is about that. You should turn off the lambda trigger from IoT service or handle the request when it comes from IoT Service.
2. I'm not sure about the forbidden error but it is more like you sent unstructured message to API gateway WS, it should be connection.send(JSON.stringify({ action: "sendmessage", data: "hello world" })); instead of connection.send("hello world");

Edited based on post update:

I know ws is there because if I console it it returns a big object with a bunch of functions

Lambda function is not really a server, it is an instance Node environment (that's why it is called FUNCTION), Lambda function doesn't work as the way you think normal Nodejs app does, its container (node environment) usually is halted (or freeze) whenever its job is done so you cannot keep its container alive like a normal server. That's the reason while you can console log the Websocket object, you cannot keep it alive, the NodeJS container was already halted whenever you return/response.

Since you cannot use the Websocket object to open WS connection in Lambda, Amazon offers a way to do that via API Gateway. The way we work with API Gateway Websocket is different than the normal server does too, it would be something like:

• User -> request to API Gateway to connect to websocket -> call Lambda 1 (onconnect function)
• User -> request to API Gateway to send message over Websocket -> call Lambda 2 (sendmessage function)
• User -> request to API Gateway to close connection -> call Lambda 3 (ondisconnect function)

3 settings above is configured in API Gateway (https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-websocket-api-integrations.html), logic of 3 functions onconnect, sendmessage, ondisconnect can be handled in 1 lambda or 3 lambda functions depending on the way we design, I check your 3 lambda functions and it looks okay.

I see that you want to use IoT but I'm not sure why. You should test your Websocket API first without anything related to IoT. It would be better if you can tell what you want to achieve here since IoT works more like a publish/subscribe/messaging channel and I don't think it's necessary to use it here.

I got an aswer from the ws github issues, so I am posting it for anyone else

There might be easier methods but this is what I can do now ... probably can be narrowed down to a single line with some tweaking

Turns out this line

endpoint := fmt.Sprintf("https://%s/%s/@connections/%s", domain, stage, connectionID)

needs to turn into this

endpoint := fmt.Sprintf("https://%s/%s/", domain, stage)