Netty_01_最简单的服务器与客户端之间的交互

Server:

public class HelloServer {
    public static void main(String[] args) {
        // 服务器端启动器,将下面的组件进行启动
        new ServerBootstrap()
                // 2.BossEventGroup, WorkerEventGroup
                // 检查IO事件
                .group(new NioEventLoopGroup())
                // 选择NIO, ServerSocketChannel实现
                .channel(NioServerSocketChannel.class)
                // 分工boss处理连接,worker处理读写
                .childHandler(
                        // 和客户端通信的通道,初始化,添加别的handler
                        new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        // 解码的handler
                        ch.pipeline().addLast(new StringDecoder());
                        // 自定义handler
                        ch.pipeline().addLast(new ChannelInboundHandlerAdapter(){
                            @Override
                            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                                // 打印上一步转化的字符串
                                System.out.println(msg);
                            }
                        });
                    }
                })
                .bind(8080);
    }
}

Client:

public class HelloClient {
    public static void main(String[] args)throws Exception {
        new Bootstrap()
                .group(new NioEventLoopGroup())
                .channel(NioSocketChannel.class)
                .handler(new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new StringEncoder());
                    }
                })
                .connect(new InetSocketAddress("localhost", 8080))
                // 阻塞方法
                .sync()
                // 代表连接对象
                .channel()
                // 发数据
                // 收发数据都走handler

                .writeAndFlush("hello, world");
    }
}

EventLoop:事件循环:处理channel上的io事件,处理数据的工人
pipline:处理数据的工序:inbound,outbound,合在一起为pipLine
EventLoopGroup:事件循环组