Netty 网络编程的秘籍，看这一篇够了

@Slf4j
public class Server {

    private EventLoopGroup boosGroup;

    private EventLoopGroup workGroup;

    public Server(int port){
        try {
            init(port);
            log.info("----- 服务启动成功 -----");
        } catch (InterruptedException e) {
            log.error("启动服务出错：{}", e.getCause());
        }
    }

    private void init(int port) throws InterruptedException {
        // 处理连接
        this.boosGroup = new NioEventLoopGroup();
        // 处理业务
        this.workGroup = new NioEventLoopGroup();

        ServerBootstrap bootstrap = new ServerBootstrap();
        // 绑定
        bootstrap.group(boosGroup, workGroup)
                .channel(NioServerSocketChannel.class) //配置服务端
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 3000)
                .option(ChannelOption.SO_BACKLOG, 1024)
                .childOption(ChannelOption.TCP_NODELAY, true)
                .childOption(ChannelOption.SO_RCVBUF, 1024)
                .childOption(ChannelOption.SO_SNDBUF, 1024)
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel socketChannel) throws Exception {
                        socketChannel.pipeline().addLast(new ServerHandler());
                    }
                });

        ChannelFuture channelFuture = bootstrap.bind(port).sync();
        channelFuture.channel().closeFuture().sync();
    }

    public void close(){
        this.boosGroup.shutdownGracefully();
        this.workGroup.shutdownGracefully();
    }

}

@Slf4j
class ServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info(">>>>>>> server active");
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        //1. 读取客户端的数据(缓存中去取并打印到控制台)
        ByteBuf buf = (ByteBuf) msg;
        byte[] request = new byte[buf.readableBytes()];
        buf.readBytes(request);
        String requestBody = new String(request, "utf-8");
        log.info(">>>>>>>>> receive message: {}", requestBody);

        //2. 返回响应数据
        ctx.writeAndFlush(Unpooled.copiedBuffer((requestBody+" too").getBytes()));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
    }
}

@Slf4j
public class Client {

    private EventLoopGroup workGroup;
    private ChannelFuture channelFuture;

    public Client(int port){
        init(port);
    }

    private void init(int port){
        this.workGroup = new NioEventLoopGroup();

        Bootstrap bootstrap = new Bootstrap();
        bootstrap.group(workGroup)
                .channel(NioSocketChannel.class)
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 3000)
                .option(ChannelOption.SO_RCVBUF, 1024)
                .option(ChannelOption.SO_SNDBUF, 1024)
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel socketChannel) throws Exception {
                        socketChannel.pipeline().addLast(new ClientHandler());
                    }
                });

        this.channelFuture = bootstrap.connect("127.0.0.1", port).syncUninterruptibly();
    }

    /**
     *
     * @param message
     */
    public void send(String message){
        this.channelFuture.channel().writeAndFlush(Unpooled.copiedBuffer(message.getBytes()));
    }

    /**
     *
     */
    public void close(){
        try {
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        workGroup.shutdownGracefully();
    }
}

@Slf4j
class ClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info(">>>>>>> client active");
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        try {
            ByteBuf buf = (ByteBuf) msg;
            byte[] req = new byte[buf.readableBytes()];
            buf.readBytes(req);

            String body = new String(req, "utf-8");
            log.info(">>>>>>>>> receive message: {}", body);
        } finally {
            ReferenceCountUtil.release(msg);
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
    }
}

public class StarterTests {

    static int port = 9011;

    @Test
    public void startServer(){
        Server server = new Server(9011);
    }

    @Test
    public void startClient(){
        Client client = new Client(port);
        client.send("Hello Netty!");
        while (true){}
    }

}