Question

I am implementing a Jetty Websocket servlet.
When the server receives a new connection, I want to send a message that will be read by websocket’s onopen function. I want this message to be sent only during the open and not using the regular connection.SendMessage() function. Is it possible to do that? and how?

Answer 1

There is no support for this in the protocol but you could fudge something yourself.

• When your server completes a handshake, store the initial message you want to deliver to a client.
• In your client’s onopen function, send a “read initial message” request.
• In your server, check that this client hasn’t read its initial message; respond with the message; set a flag saying that the initial message has been sent.
• Your client and server are both now free to send other messages.