类图

ChannelInboundHandlerAdapter

ServerBootstrap

- attributeA- attributeB

- methodA()- methodB()

ChannelHandlerAdapter类层级关系

ChannelOutboundHandlerAdapter

ChannelHandlerAdapter

AbstractBootstrap

Bootstrap

刚开始尝试些写你自己的ChannelHandler时，你可以用ChannelInboundHandlerAdapter和ChannelOutboundHandlerAdapter这两个类。这两个适配器类分别提供了ChannelInboundHandler和ChannelOutboundHandler的基本实现。它们继承了共同的父接口ChannelHandler的方法，扩展了抽象类ChannelHandlerAdapter

ChannelOutboundHandler

ChannelInboundHandler

ChannelHandler

+ handlerAdded 当ChannelHandler被添加到一个ChannelPipeline时被调用+ handlerRemoved 当ChannelHandler从一个ChannelPipeline中移除时被调用+ exceptionCaught 处理过程中ChannelPipeline中发生错误时被调用