channelhandle的生命周期
背景
新建连接
handlerAdded() –> channelRegistered() –> channelActive()
连接完成
channelRead() –> channelReadComplete()
关闭连接
channelInactive() –> channelUnregistered() –> handlerRemoved()
handlerAdded() –> channelRegistered() –> channelActive()
channelRead() –> channelReadComplete()
channelInactive() –> channelUnregistered() –> handlerRemoved()