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一、引入依赖

在项目中首先需要配置所需的依赖包。Netty作为依赖包需要手动添加，建议访问Maven仓库获取最新版本。以下是常用的依赖配置：

   
    
    
    
    
        
     
      io.netty
     
        
     
      netty-all
     
        
     
      4.1.25.Final
     
    
    
    
    
    
    
        
     
      org.projectlombok
     
        
     
      lombok
     
        
     
      1.16.22
     
    
    
   

二、服务器端实现

完成依赖配置后，接下来编写服务器端代码。以下是一个简单的Netty服务器实现：

public class LiuServer {
    private final int port;
    public LiuServer(int port) {
        this.port = port;
    }
    public static void main(String[] args) throws Exception {
        int port = 8888;
        new LiuServer(port).start();
    }
    public void start() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .localAddress(new InetSocketAddress(port))
                    .childHandler(new ChannelInitializer
   
    () {
                        @Override
                        public void initChannel(SocketChannel ch) {
                            ch.pipeline().addLast(new LiuServerHandler());
                        }
                    });
            ChannelFuture f = b.bind().sync();
            System.out.println(LiuServer.class.getName() + " 服务启动开始监听端口：" + f.channel().localAddress());
            f.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}
//服务器处理类
@ChannelHandler.Sharable
public class LiuServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf in = (ByteBuf) msg;
        System.out.println("客户端发来消息: " + in.toString(CharsetUtil.UTF_8));
        ctx.write(in);
    }
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        System.out.println("channel 通道读取完成");
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}
   

三、客户端实现

客户端需要连接到服务器，以下是一个简单的Netty客户端实现：

public class LiuClient {
    private final String host;
    private final int port;
    public LiuClient(String host, int port) {
        this.host = host;
        this.port = port;
    }
    public static void main(String[] args) throws Exception {
        final String host = "127.0.0.1";
        final int port = 8888;
        new LiuClient(host, port).start();
    }
    public void start() throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .remoteAddress(new InetSocketAddress(host, port))
                    .handler(new ChannelInitializer
   
    () {
                        @Override
                        public void initChannel(SocketChannel ch) {
                            ch.pipeline().addLast(new LiuClientHandler());
                        }
                    });
            ChannelFuture f = b.connect().sync();
            f.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
}
//客户端处理类
@ChannelHandler.Sharable
public class LiuClientHandler extends SimpleChannelInboundHandler
    
      {
    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(Unpooled.copiedBuffer("Hello Netty! " + Long.toString(System.currentTimeMillis()), CharsetUtil.UTF_8));
    }
    @Override
    public void channelRead0(ChannelHandlerContext ctx, ByteBuf in) {
        System.out.println("服务器发来消息: " + in.toString(CharsetUtil.UTF_8));
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}
    
   

以上代码提供了一个完整的Netty服务器端和客户端实现，适用于基础的网络通信应用开发。

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