<!--lombok-->
<dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
  <version>1.18.2</version>
  <optional>true</optional>
</dependency>
<!--netty-->
<dependency>
  <groupId>io.netty</groupId>
  <artifactId>netty-all</artifactId>
  <version>4.1.17.Final</version>
</dependency>

@Slf4j
public class NettyServer {
    public void start() {
        InetSocketAddress socketAddress = new InetSocketAddress("127.0.0.1", 8082);
        //new 一個(gè)主線程組
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        //new 一個(gè)工作線程組
        EventLoopGroup workGroup = new NioEventLoopGroup(200);
        ServerBootstrap bootstrap = new ServerBootstrap()
                .group(bossGroup, workGroup)
                .channel(NioServerSocketChannel.class)
                .childHandler(new ServerChannelInitializer())
                .localAddress(socketAddress)
                //設(shè)置隊(duì)列大小
                .option(ChannelOption.SO_BACKLOG, 1024)
                // 兩小時(shí)內(nèi)沒(méi)有數(shù)據(jù)的通信時(shí),TCP會(huì)自動(dòng)發(fā)送一個(gè)活動(dòng)探測(cè)數(shù)據(jù)報(bào)文
                .childOption(ChannelOption.SO_KEEPALIVE, true);
        //綁定端口,開(kāi)始接收進(jìn)來(lái)的連接
        try {
            ChannelFuture future = bootstrap.bind(socketAddress).sync();
            log.info("服務(wù)器啟動(dòng)開(kāi)始監(jiān)聽(tīng)端口: {}", socketAddress.getPort());
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            log.error("服務(wù)器開(kāi)啟失敗", e);
        } finally {
            //關(guān)閉主線程組
            bossGroup.shutdownGracefully();
            //關(guān)閉工作線程組
            workGroup.shutdownGracefully();
        }
    }
}

/**
* netty服務(wù)初始化器
**/
public class ServerChannelInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        //添加編解碼
        socketChannel.pipeline().addLast("decoder", new StringDecoder(CharsetUtil.UTF_8));
        socketChannel.pipeline().addLast("encoder", new StringEncoder(CharsetUtil.UTF_8));
        socketChannel.pipeline().addLast(new NettyServerHandler());
    }
}

/**
* netty服務(wù)端處理器
**/
@Slf4j
public class NettyServerHandler extends ChannelInboundHandlerAdapter {
    /**
     * 客戶端連接會(huì)觸發(fā)
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info("Channel active......");
    }
    /**
     * 客戶端發(fā)消息會(huì)觸發(fā)
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        log.info("服務(wù)器收到消息: {}", msg.toString());
        ctx.write("你也好哦");
        ctx.flush();
    }
    /**
     * 發(fā)生異常觸發(fā)
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

/**
* 啟動(dòng)類
*
*/
@Slf4j
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class RpcServerApp extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(RpcServerApp.class);
    }
    /**
     * 項(xiàng)目的啟動(dòng)方法
     *
     * @param args
     */
    public static void main(String[] args) {
        SpringApplication.run(RpcServerApp.class, args);
        //開(kāi)啟Netty服務(wù)
        NettyServer nettyServer = new NettyServer ();
        nettyServer.start();
        log.info("======服務(wù)已經(jīng)啟動(dòng)========");
    }
}

/**
* Netty客戶端
**/
@Slf4j
public class NettyClientUtil {
    public static ResponseResult helloNetty(String msg) {
        NettyClientHandler nettyClientHandler = new NettyClientHandler();
        EventLoopGroup group = new NioEventLoopGroup();
        Bootstrap bootstrap = new Bootstrap()
                .group(group)
                //該參數(shù)的作用就是禁止使用Nagle算法，使用于小數(shù)據(jù)即時(shí)傳輸
                .option(ChannelOption.TCP_NODELAY, true)
                .channel(NioSocketChannel.class)
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel socketChannel) throws Exception {
                        socketChannel.pipeline().addLast("decoder", new StringDecoder());
                        socketChannel.pipeline().addLast("encoder", new StringEncoder());
                        socketChannel.pipeline().addLast(nettyClientHandler);
                    }
                });
        try {
            ChannelFuture future = bootstrap.connect("127.0.0.1", 8082).sync();
            log.info("客戶端發(fā)送成功....");
            //發(fā)送消息
            future.channel().writeAndFlush(msg);
            // 等待連接被關(guān)閉
            future.channel().closeFuture().sync();
            return nettyClientHandler.getResponseResult();
        } catch (Exception e) {
            log.error("客戶端Netty失敗", e);
            throw new BusinessException(CouponTypeEnum.OPERATE_ERROR);
        } finally {
            //以一種優(yōu)雅的方式進(jìn)行線程退出
            group.shutdownGracefully();
        }
    }
}

/**
* 客戶端處理器
**/
@Slf4j
@Setter
@Getter
public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    private ResponseResult responseResult;
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info("客戶端Active .....");
    }
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        log.info("客戶端收到消息: {}", msg.toString());
        this.responseResult = ResponseResult.success(msg.toString(), CouponTypeEnum.OPERATE_SUCCESS.getCouponTypeDesc());
        ctx.close();
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

@RestController
@Slf4j
public class UserController {
    @PostMapping("/helloNetty")
    @MethodLogPrint
    public ResponseResult helloNetty(@RequestParam String msg) {
        return NettyClientUtil.helloNetty(msg);
    }
}