客户端代码：

package cn.alex;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;

public class test {

    public static void main(String[] args) {

        for (int i = 0; i < 10; i++) {


                try {
                    Socket socket = new Socket();
                    socket.connect(new InetSocketAddress(9092));
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
                System.out.println("connected");

        }

    }

}

服务端代码

package cn.alex;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class NettyIMServerApplication {

    public void startServer() throws InterruptedException {
        // 处理 accept事件
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        // 处理读写事件
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        ServerBootstrap bootstrap = new ServerBootstrap();

        bootstrap.group(bossGroup, workerGroup);
        bootstrap.channel(NioServerSocketChannel.class);
        bootstrap.childHandler(new ChannelInitializer<>() {
            @Override
            protected void initChannel(Channel channel) throws Exception {
                System.out.println("init " + channel.id());
            }
        });

        Runtime.getRuntime().addShutdownHook(new Thread(()->{
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }));
        ChannelFuture channelFuture = bootstrap.bind(9092).sync();
        System.out.println("服务启动成功，监听端口为 9092");
        // 这里会阻塞掉主线程，实现服务长期开启
        channelFuture.channel().closeFuture().sync();
    }


    public static void main(String[] args) throws InterruptedException {
        NettyIMServerApplication application = new NettyIMServerApplication();
        application.startServer();
    }

}

谢谢老师