server never switches to websocket

[vkurland]

I am testing v1.0.3 with jetty 9.2.x (could not get jetty 9.4.x to work for me for unrelated reasons). Server-side socket-io servlet always uses long poll and never switches to websocket. I am attaching a screenshot of the Chrome developer tools panel that shows that the server always returns 200 and never 101 (protocol switch). I have seen the 101 response with socket-io library v1.0.2

Is there some special initialization I should do to enable websocket transport? I need the library to support both websocket and long poll.

[alexsaveliev]

@vkurland I'd like to see your code, if possible. It's hard to identify the reason of the problem now, sorry.

Some questions and ideas:

• how does your app looks? is it webapp (war) that runs by Jetty web server installed or it embeds Jetty web server?
• if your app embeds Jetty web server I'd suggest to check the following:
  • do you have runtime dependency on Jetty's websocket server implementation? Ensure that you do have org.eclipse.jetty.websocket:javax-websocket-server-impl:${jetty.version}
  • when you are configuring your embedded Jetty server, please add the following block:

import org.eclipse.jetty.websocket.jsr356.server.deploy.WebSocketServerContainerInitializer;
       .....
        ServletContextHandler context = ...
        .....
        WebSocketServerContainerInitializer.
                configureContext(context).
                addEndpoint(WebsocketTransportConnection.class);

This code is not required when your app runs as webapp from Jetty webserver, because at your app startup Jetty uses annotations to scan for available websocket @ServerEndpoints

• there is a sample of embedded Jetty server +socket.io chat, see ChatServer.java

Catch me on Skype if you need further help

[vkurland]

thanks for getting back to me. I have opened access to my repo ( https://github.com/happygears/nw2 ), you should have the invite in your inbox. The most relevant stuff should be here : https://github.com/happygears/nw2/tree/dev/backend/src/main/java/net/happygears/nw2/socket_io

and here

https://github.com/happygears/nw2/blob/dev/backend/src/main/java/net/happygears/nw2/WebServer.java

(method socketIOContext )

all of this is in the branch "dev"

I am going to try to implement your suggestion wth WebSocketServerContainerInitializer, I know I do not do this part right now. I'll post an update here once I have tried it

[vkurland]

I have added the call to WebSocketServerContainerInitializer...addEndpoint() as you suggested but this did not change anything. It did not break anything either so I have pushed the code to branch "dev".

To answer your questions:

• this is embedded jetty. Currently I am using jetty 9.2.4. I could not get session management and authentication work with 9.4.x yet, they have changed this part very significantly.
• I have added run time dependency on javax-websocket-server-impl. I had dependencies on websocket-api and websocket-servlet but I have cleaned this up and left only javax-websocket-server-impl as you suggested.
• I have added call to WebSocketServerContainerInitializer...addEndpoint()

[alexsaveliev]

The reason of the issue was custom configuration (custom context and path).

• added initialization examples in com.codeminders.socketio.sample.jetty.ChatServer
• documented websocket initialization options in README.md