make ServerChannel as a Pubisher[Channel] about netty-reactive-streams

[He-Pin]

eg : we could turn it to StreamdTcp like
https://github.com/akka/akka/blob/release-2.3-dev/akka-stream/src/main/scala/akka/stream/scaladsl/Tcp.scala#L42

[jroper]

I think creating a publisher of channels is as simple as doing this:

Bootstrap bootstrap = new Bootstrap();
PublisherHandler<Channel> publisher = new PublisherHandler<>(Channel.class);
bootstrap.handler(publisher);
bootstrap.localAddress(...);
bootstrap.group(...);
bootstrap.bind();

Each subscriber will then need to add handlers to the pipeline, and then they need to register the channel to an event loop.

[He-Pin]

you can't use bootstrap here,cause it will register the channel to the eventloop for you .
here we should control it manually.
https://github.com/netty/netty/blob/master/transport/src/main/java/io/netty/bootstrap/ServerBootstrap.java#L181

[jroper]

It will register the ServerSocketChannel with an event loop, but that's ok, we want that. The SocketChannel for each incoming connection though won't be registered, that will be up to the subscriber. The thing that usually does that is the ServerBootstrap, but we're not using a ServerBootstrap, we're using an ordinary Bootstrap.

Anyway, I just wrote a test to test this, it works, the actual code for setup is here:

https://github.com/typesafehub/netty-reactive-streams/blob/master/netty-reactive-streams/src/test/java/com/typesafe/netty/ChannelPublisherTest.java#L37