8.向Selector注册监听读操作SelectionKey.OP_READ
2.绑定监听地址InetSocketAddress
10.decode请求消息
11.异步写ByteBuffer到SocketChannel
Reactor Thread
9.handleRead()异步读请求消息到ByteBuffer
7.设置新建客户端连接的Socket参数
5.Selector轮询就绪的Key
NioServer
1.打开ServerSocketChannel
6.handleAccept()处理新的客户端接入
IoHandler