springboot+netty，webSocket与modbu

准备工作

  springboot 2.4.2
<dependency>
  <groupId>io.netty</groupId>
  <artifactId>netty-all</artifactId>
  <version>4.1.59.Final</version>
 </dependency>

1.创建NettyServer.java,关键代码如下

public class NettyServer {
    private static final Logger logger = LoggerFactory.getLogger("-----NettyServer-----");
    private RedisUtil redisUtil;
    private HandlerService handlerService;

    private static ChannelGroup deviceChannelGroup;
    private static Map<String, ChannelId> deviceMap = new ConcurrentHashMap<>();
    /**
     * WEB-SOCKET
     */
    private static ChannelGroup socketChannelGroup;
    private static Map<String, ChannelId> socketMap = new ConcurrentHashMap<>();

    /**
     * bossGroup就是parentGroup，是负责处理TCP/IP连接的
     */
    private EventLoopGroup bossGroup = null;
    /**
     * workerGroup就是childGroup,是负责处理Channel(通道)的I/O事件
     */

    private EventLoopGroup workerGroup = null;

    public NettyServer(RedisUtil redisUtil, HandlerService handlerService) {
        bossGroup = new NioEventLoopGroup(1);
        workerGroup = new NioEventLoopGroup();
        this.redisUtil = redisUtil;
        this.handlerService = handlerService;
        deviceChannelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
        socketChannelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
    }

    public void bind(int tcp,int socket) throws Exception {
        ServerBootstrap device = new ServerBootstrap();
        device.group(bossGroup, workerGroup)
                .channel(NioServerSocketChannel.class)
                //初始化服务端可连接队列,指定了队列的大小128
                .option(ChannelOption.SO_BACKLOG, 1024)
                //保持长连接
                .childOption(ChannelOption.SO_KEEPALIVE, true)
                .childOption(ChannelOption.RCVBUF_ALLOCATOR, new FixedRecvByteBufAllocator(65535))
                .childOption(ChannelOption.TCP_NODELAY, true)
                .childOption(ChannelOption.SO_REUSEADDR, true)
                // 绑定客户端连接时候触发操作
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel sh) throws Exception {
                        InetSocketAddress address = sh.remoteAddress();

                        logger.debug("TCP 客户端IP:" + address.getAddress() + ":" + address.getPort());
                        sh.pipeline()
                                //项目需要，定长消息，可以替换为其他的
                                .addLast(new FixedLengthFrameDecoder(10))
                                //消息处理
                                .addLast("HeartBeat", new HeartBeatHandler(redisUtil, handlerService));
                    }
                });
        //绑定监听端口，调用sync同步阻塞方法等待绑定操作完成，完成后返回ChannelFuture类似于JDK中Future

        ServerBootstrap webSocket = new ServerBootstrap();
        webSocket.group(bossGroup, workerGroup)
                .channel(NioServerSocketChannel.class)
                //初始化服务端可连接队列,指定了队列的大小128
                .option(ChannelOption.SO_BACKLOG, 1024)
                //保持长连接
                .childOption(ChannelOption.SO_KEEPALIVE, true)
                .childOption(ChannelOption.RCVBUF_ALLOCATOR, new FixedRecvByteBufAllocator(65535))
                .childOption(ChannelOption.TCP_NODELAY, true)
                .childOption(ChannelOption.SO_REUSEADDR, true)
                // 绑定客户端连接时候触发操作
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel sh) throws Exception {
                        InetSocketAddress address = sh.remoteAddress();

                        logger.debug("WEB SOCKET客户端IP:" + address.getAddress() + ":" + address.getPort());
                        sh.pipeline()
                                .addLast(new HttpServerCodec())
                                .addLast(new ChunkedWriteHandler())
                                .addLast(new HttpObjectAggregator(65535))
                                .addLast(new WebSocketServerProtocolHandler("/ws", "WebSocket", true, 65535))
                                .addLast(new WebSocketHandler());
                    }
                });
        //绑定监听端口，调用sync同步阻塞方法等待绑定操作完成，完成后返回ChannelFuture类似于JDK中Future
        ChannelFuture futureDevice = device.bind(tcp).sync();
        ChannelFuture futureWebSocket = webSocket.bind(socket).sync();
        if (futureDevice.isSuccess()) {
            logger.debug("TCP 服务端启动成功");
        } else {
            logger.debug("TCP 服务端启动失败");
            futureDevice.cause().printStackTrace();
            bossGroup.shutdownGracefully(); //关闭线程组
            workerGroup.shutdownGracefully();
        }
        if (futureWebSocket.isSuccess()) {
            logger.debug("WEB-SOCKET服务端启动成功");
        } else {
            logger.debug("WEB-SOCKET服务端启动失败");
            futureWebSocket.cause().printStackTrace();
            bossGroup.shutdownGracefully(); //关闭线程组
            workerGroup.shutdownGracefully();
        }
        //成功绑定到端口之后,给channel增加一个 管道关闭的监听器并同步阻塞,直到channel关闭,线程才会往下执行,结束进程。
        futureDevice.channel().closeFuture().sync();
        futureWebSocket.channel().closeFuture().sync();

    }

    public void unbind() {
        if (null != bossGroup && !bossGroup.isShutdown()) {
            bossGroup.shutdownGracefully();
            bossGroup = null;
        }
        if (null != workerGroup && !workerGroup.isShutdown()) {
            workerGroup.shutdownGracefully();
            workerGroup = null;
        }
    }

    /**
     * WEB-SOCKET 操作 开始
     */
    public static void socketAdd(Channel channel) {
        socketChannelGroup.add(channel);
    }

    public static void socketRemove(Channel channel) {
        socketChannelGroup.remove(channel);
        removeSocketChannelId(channel.id());
    }

    public static ChannelGroup socketChannelGroup() {
        return socketChannelGroup;
    }

    public static void putSocketChannelId(String code, ChannelId channelId) {
        socketMap.put(code, channelId);
    }

    public static void removeSocketChannelId(ChannelId channelId) {
        socketMap.entrySet().removeIf(item -> item.getValue().equals(channelId));
    }
    public static ChannelId socketChannelId(String code) {
        return socketMap.getOrDefault(code, null);
    }

    public static Channel socketChannel(ChannelId channelId){
        return socketChannelGroup.find(channelId);
    }
    public static Map<String,ChannelId> socketMap(){
        return socketMap;
    }

    /**
     * WEB-SOCKET 操作结束
     * DEVICE 操作 开始
     */
    public static void deviceAdd(Channel channel) {
        deviceChannelGroup.add(channel);
    }

    public static void deviceRemove(Channel channel) {
        deviceChannelGroup.remove(channel);
        removeDeviceChannelId(channel.id());
    }

    public static ChannelGroup deviceChannelGroup() {
        return deviceChannelGroup;
    }

    public static void putDeviceChannelId(String code, ChannelId channelId) {
        deviceMap.put(code, channelId);
    }

    public static void removeDeviceChannelId(ChannelId channelId) {
        deviceMap.entrySet().removeIf(item -> item.getValue().equals(channelId));
    }

    public static ChannelId deviceChannelId(String code) {
        return deviceMap.getOrDefault(code, null);
    }

    public static Channel deviceChannel(ChannelId channelId){
        return deviceChannelGroup.find(channelId);
    }
    public static Map<String,ChannelId> deviceMap(){
        return deviceMap;
    }
    /**
     * DEVICE 操作 结束
     */
}

2.创建对应消息处理类

2.1（ModBus）消息处理类 HeartBeatHandler.java

@ChannelHandler.Sharable
public class HeartBeatHandler extends ChannelInboundHandlerAdapter {
    private static final Logger logger = LoggerFactory.getLogger("-----HeartBeatHandler-----");
    private RedisUtil redisUtil;
    private HandlerService handlerService;

    public HeartBeatHandler(RedisUtil redisUtil, HandlerService handlerService) {
        this.redisUtil = redisUtil;
        this.handlerService = handlerService;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        //以下为示例代码，具体按实际功能需求来；
        String code = "具体获取code操作";
        sendMessageToWebSocket(code,"发送消息");
    }

    public void sendMessageToWebSocket(String code, String message) {
        ChannelId channelId = NettyServer.socketChannelId(code);
        if (channelId != null) {
            Channel socketChannel = NettyServer.socketChannel(channelId);
            if (socketChannel != null) {
                socketChannel.writeAndFlush(new TextWebSocketFrame(message)).addListener((ChannelFutureListener) future -> {
                    logger.info("WEB SOCKET {},{}", code, message);
                    logger.info("WEB SOCKET DONE:{}", future.isDone());
                    logger.info("WEB SOCKET SUCCESS:{}", future.isSuccess());
                });
            } else {
                logger.info("channels is null");
            }
        } else {
            logger.info("channelsId is null");
        }
    }
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        logger.info("接收到客户端信息完成");
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        if (cause instanceof Exception) {
            logger.info("异常捕获");
            cause.printStackTrace();
        }
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        logger.info("CLIENT" + getRemoteAddress(ctx) + " 接入连接");
        NettyServer.deviceAdd(ctx.channel());
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        logger.info("CLIENT" + getRemoteAddress(ctx) + " 断开连接");
        NettyServer.deviceRemove(ctx.channel());
        ctx.close();
    }

    public static String getRemoteAddress(ChannelHandlerContext ctx) {
        return ctx.channel().remoteAddress().toString();
    }

2.2（WebSocket）消息处理类 WebSocketHandler.java

public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
    private static final Logger logger = LoggerFactory.getLogger(WebSocketHandler.class);
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        channel.id();
        logger.info("与客户端建立连接，通道开启！channelId:{}",channel.id());
        // 添加到channelGroup通道组
        NettyServer.socketAdd(ctx.channel());
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        logger.info("与客户端建立连接，通道关闭！");
        NettyServer.socketRemove(ctx.channel());
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
        logger.info("服务器收到的数据：" + msg.text());
        NettyServer.putSocketChannelId(msg.text(),ctx.channel().id());
        //简易的保持心跳
        sendMessage(ctx);
    }

    private void sendMessage(ChannelHandlerContext ctx) {
        logger.info("服务器回复：0");
        ctx.channel().writeAndFlush(new TextWebSocketFrame("0")).addListener((ChannelFutureListener) future -> {
            logger.info("WEB-SOCKET 心跳回复:0");
            logger.info("WEB SOCKET DONE:{}",future.isDone());
            logger.info("WEB SOCKET SUCCESS:{}",future.isSuccess());
        });;
    }

    private void sendAllMessage() {
        String message = "发送群消息";
        NettyServer.socketChannelGroup().writeAndFlush(new TextWebSocketFrame(message));
    }

3.使用方法

在对应的SpringBoot 启动类中使用
@Component
public static class StartApplication implements ApplicationRunner {
  private NettyServer nettyServer;
      @Resource
      private HandlerService handlerService;
      @Resource
      private RedisUtil redis;
      @Override
      public void run(ApplicationArguments args) throws Exception {
          logger.info("进程开启！");
          nettyServer = new NettyServer(redis, handlerService);
          nettyServer.bind(port1,port2);
      }
      @PreDestroy
      public void destroy() throws Exception {
          logger.info("进程关闭！");
          nettyServer.unbind();
        }
}

4.至此，功能完成

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