配置类

import cn.hutool.core.thread.ThreadUtil;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;

@Component
@Slf4j
public class NettyServerConfig {

    @Resource
    private BizHandler bizHandler;

    @Value("${netty.port}")
    private int port;


    @PostConstruct
    public void start(){
        ThreadUtil.newSingleExecutor().execute(this::doStart);
    }


    public void doStart(){
        ServerBootstrap serverBootstrap = new ServerBootstrap();
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workGroup = new NioEventLoopGroup();

        serverBootstrap.group(bossGroup,workGroup)
                .channel(NioServerSocketChannel.class)
                .option(ChannelOption.SO_BACKLOG, 1024)
                .childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .childHandler(new ChannelInitializer<SocketChannel>(){

                    @Override
                    protected void initChannel(SocketChannel socketChannel) {
                        ChannelPipeline pipeline = socketChannel.pipeline();
                        pipeline.addFirst(bizHandler);
                    }
                });

        ChannelFuture channelFuture;
        try {
            channelFuture = serverBootstrap.bind(port).sync();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }

        channelFuture.addListener(future -> {
            if(future.isSuccess()){
                log.info("netty服务 启动成功");
            }
        });

        ChannelFuture closeFuture = channelFuture.channel().closeFuture();
        try {
            closeFuture.sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }

    }
}

处理器

import com.google.common.collect.Lists;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;


import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

@Slf4j
@Service
@ChannelHandler.Sharable
public class BizHandler extends ChannelInboundHandlerAdapter {

    private static final String SPACE = " ";

    private static final ConcurrentHashMap<ChannelHandlerContext, String> channelContextMap = new ConcurrentHashMap<>();

    
    public void send(){
        channelContextMap.entrySet().forEach(e -> {

            ChannelHandlerContext context = e.getKey();
            ByteBuf buf = context.alloc().buffer();
            byte[] dataFrame = generateDataFrame();
            buf.writeBytes(dataFrame);
            context.channel().writeAndFlush(buf);
        });
    }


    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf buffer = (ByteBuf) msg;
        byte[] bytes = new byte[buffer.readableBytes()];
        buffer.readBytes(bytes);
        String msgHexStr = this.byteArrayToHexString(bytes);
        
        //如果不是预期的连接发过来消息 主动断开连接
        //ctx.channel().close();
        
        ctx.fireChannelRead(msg);
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) {
        channelContextMap.remove(ctx);
    }

    private String byteArrayToHexString(byte[] bytes) {
        List<String> dataFrame = Lists.newArrayList();
        for (byte b : bytes) {
            String hex = Integer.toHexString(0xFF & b);
            if (hex.length() == 1) {
                // 如果是一位的话，要补0
                hex = "0" + hex;
            }
            dataFrame.add(hex.toUpperCase());
        }
        return dataFrame.stream().collect(Collectors.joining(SPACE));
    }

}