Netty 服务转发Tcp请求

import io.netty.bootstrap.Bootstrap;  
import io.netty.bootstrap.ServerBootstrap;  
import io.netty.buffer.ByteBuf;  
import io.netty.channel.*;  
import io.netty.channel.nio.NioEventLoopGroup;  
import io.netty.channel.socket.SocketChannel;  
import io.netty.channel.socket.nio.NioServerSocketChannel;  
import io.netty.channel.socket.nio.NioSocketChannel;  
import io.netty.handler.logging.LogLevel;  
import io.netty.handler.logging.LoggingHandler;  
  
public class AgentProxyServer {  
    Bootstrap bootstrap;  
    ServerBootstrap server;  
  
    NioEventLoopGroup bossGroup;  
    NioEventLoopGroup workGroup;  
  
    class DataHandler extends ChannelInboundHandlerAdapter {  
        private Channel channel;  
  
        public DataHandler(Channel channel) {  
            this.channel = channel;  
        }  
  
        @Override  
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {  
            ByteBuf readBuffer = (ByteBuf) msg;  
            readBuffer.retain();  
            channel.writeAndFlush(readBuffer);  
        }  
    }  
  
    void init() {  
        // 初始化
        this.bossGroup = new NioEventLoopGroup();  
        this.workGroup = new NioEventLoopGroup();  
        this.server = new ServerBootstrap();  
        this.bootstrap = new Bootstrap();  
        bootstrap.channel(NioSocketChannel.class);  
        bootstrap.group(bossGroup);  
        this.server.group(bossGroup, workGroup);  

        
        server.channel(NioServerSocketChannel.class).handler(new LoggingHandler(LogLevel.INFO))  
                .childHandler(new ChannelInitializer<SocketChannel>(  
                ) {  
                    @Override  
                    protected void initChannel(SocketChannel socketChannel) throws Exception {  
                        socketChannel.pipeline().addLast("serverHandler", new DataHandler(getClientChannel(socketChannel)));  
                    }  
                }).option(ChannelOption.SO_BACKLOG, 1024)  
                .option(ChannelOption.SO_RCVBUF, 16 * 1024);  
  
// 监听地址
server.bind(50050).syncUninterruptibly().addListener((ChannelFutureListener) channelFuture -> {  
            if (channelFuture.isSuccess()) {  
                System.out.println("服务区启动成功");  
            } else {  
                System.out.println("服务器启动失败");  
            }  
        });  
    }  
  
    private Channel getClientChannel(SocketChannel ch) throws InterruptedException {  
        this.bootstrap.handler(new ChannelInitializer<SocketChannel>() {  
            @Override  
            protected void initChannel(SocketChannel socketChannel) throws Exception {  
                socketChannel.pipeline().addLast("clientHandler", new DataHandler(ch));  
            }  
       });  
//  转发地址
        ChannelFuture sync = bootstrap.connect("192.168.20.49", 22).sync();  
        return sync.channel();  
    }  
  
    public static void main(String[] args) {  
        AgentProxyServer agentProxyServer = new AgentProxyServer();  
        agentProxyServer.init();  
    }  
}