1.服务端启动案例

Maven依赖

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>4.1.6.Final</version>
</dependency>

目录结构

Server启动类

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.util.AttributeKey;

/**
 * @author 倚栏听风
 * @date 2022/4/23 10:08
 */
public class Server {
    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            //辅助类
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workGroup)
                    .channel(NioServerSocketChannel.class)
                    //设置TCP连接基本属性
                    .childOption(ChannelOption.TCP_NODELAY, true)
                    //设置创建连接时绑定基本属性
                    .childAttr(AttributeKey.newInstance("childAttr"), "childAttrValue")
                    .handler(new ServerHandler())
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {

                        }
                    });
            ChannelFuture future = bootstrap.bind(8888).sync();
            future.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}

ServerHandler类

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

/**
 * @author 倚栏听风
 * @date 2022/4/23 10:22
 */
public class ServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channelRegistered");
    }

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        System.out.println("handlerAdded");
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channelActive");
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println("channelRead");
    }
}