WebSocket client API

[Andrej Golovnin]

Hi Pavel,

>> - Where's the .ping() or .pong() ?
> 
> * @apiNote Keep-alive features of WebSocket protocol are taken care of
> * completely by implementations and are not exposed in this API.
> 
> We thought that a high-level API could live without this burden for the user. At
> the same time the implementation will definitely have several configuration
> parameters, tweaking its behaviour in respect to keep-alive features.
> 
> Yes, we've thought about application data that can be carried by those types of
> messages, but due to restrictions to their size (125 bytes) and potential
> out-of-order delivery we've decided not to expose them as data carriers.

Just because you don’t see usages for it, it does not mean that others don’t need
it. We have an application which already make use of it. And if you don’t add
at least the #ping(ByteBuffer) method, it would not be usable for us and we will
stay with JSR 356. What I also miss, is the ability to define custom HTTP header
values which should be transmitted during the handshake.

And I think you should add an API to define the proxy in case some one use just
WebSocket.newBuilder(String). And please use the class java.net.Proxy to define
a proxy and not just a String and a InetSocketAddress as it is done in HttpClient.

Best regards,
Andrej Golovnin