netty tcp

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EventLoopGroup bossGroup = new NioEventLoopGroup(); //这个是用于serversocketchannel的eventloop
          
EventLoopGroup workerGroup = new NioEventLoopGroup(); //这个是用于处理accept到的channel
          
try {
              
ServerBootstrap b = new ServerBootstrap(); //构建serverbootstrap对象
              
b.group(bossGroup, workerGroup); //设置时间循环对象，前者用来处理accept事件，后者用于处理已经建立的连接的io
              
b.channel(NioServerSocketChannel.class); //用它来建立新accept的连接，用于构造serversocketchannel的工厂类
              
b.childHandler(new ChannelInitializer<SocketChannel>(){ //为accept channel的pipeline预添加的inboundhandler
                  
@Override //当新连接accept的时候，这个方法会调用
                  
protected void initChannel(SocketChannel ch) throws Exception {
                      
// TODO Auto-generated method stub
                      
ch.pipeline().addLast(new MyChannelHandler()); //为当前的channel的pipeline添加自定义的处理函数
                  
} 

});
              
//bind方法会创建一个serverchannel，并且会将当前的channel注册到eventloop上面，
              
//会为其绑定本地端口，并对其进行初始化，为其的pipeline加一些默认的handler
              
ChannelFuture f = b.bind(80).sync();
              
f.channel().closeFuture().sync(); //相当于在这里阻塞，直到serverchannel关闭
          
} finally {
              
bossGroup.shutdownGracefully();
              
workerGroup.shutdownGracefully();
          
} 

//这里parent用于执行server的accept时间事件，child才是用于执行获取的channel连接的事件
  
public ServerBootstrap group(EventLoopGroup parentGroup, EventLoopGroup childGroup) {
      
super.group(parentGroup);
      
if (childGroup == null) {
          
throw new NullPointerException("childGroup");
      
}
      
if (this.childGroup != null) {
          
throw new IllegalStateException("childGroup set already");
      
}
      
this.childGroup = childGroup;
      
return this;
  
}