项目源码在github上，请看这里-->Android Netty Server
Android netty server
Start a netty server on android
Download netty
Download url :https://netty.io/downloads.html
Download netty-all.jar and put it into libs. Then add as library.
Project structure
netty
AppServer
AppServerHandler
AppServerInitializer
IServer
MessageProtocol
TcpProtoCodec
MainActivity
MessageEvent
AppServerHandler: handle channel add, remove and activity. in this class, channelRead0 will handle the message which send by client.
AppServerInitializer: initialize AppServer. Then add Tcp Protocol Codec and AppServerHandler.
AppServer: start netty server.
MessageProtocol: netty send and receive message format.
MessageEvent: use for eventbus.
MainActivity: show receive message content.
Communication protocol
'R' + data.length + data
