netty结合websocket实现音视频通话的前后端代码框架

下面是一个简单的 Netty 结合 WebSocket 实现音视频通话的前后端代码框架：

前端代码：

// 创建 WebSocket 连接
const socket = new WebSocket('ws://localhost:8080');

// 监听连接成功事件
socket.onopen = () => {
  console.log('WebSocket 连接成功');
};

// 监听消息事件
socket.onmessage = (event) => {
  const message = JSON.parse(event.data);

  // 处理消息
  switch (message.type) {
    case 'offer':
      handleOffer(message.offer);
      break;
    case 'answer':
      handleAnswer(message.answer);
      break;
    case 'candidate':
      handleCandidate(message.candidate);
      break;
    default:
      console.error('未知消息类型');
  }
};

// 监听连接关闭事件
socket.onclose = () => {
  console.log('WebSocket 连接关闭');
};

// 处理 offer 消息
function handleOffer(offer) {
  // 创建 PeerConnection
  const pc = new RTCPeerConnection();

  // 处理 ICE 候选人
  pc.onicecandidate = (event) => {
    if (event.candidate) {
      send({
        type: 'candidate',
        candidate: event.candidate,
      });
    }
  };

  // 设置远程描述
  pc.setRemoteDescription(new RTCSessionDescription(offer));

  // 创建应答
  pc.createAnswer().then((answer) => {
    pc.setLocalDescription(answer);

    // 发送应答
    send({
      type: 'answer',
      answer: answer,
    });
  });
}

// 处理 answer 消息
function handleAnswer(answer) {
  // 设置远程描述
  pc.setRemoteDescription(new RTCSessionDescription(answer));
}

// 处理 candidate 消息
function handleCandidate(candidate) {
  // 添加 ICE 候选人
  pc.addIceCandidate(new RTCIceCandidate(candidate));
}

// 发送消息
function send(message) {
  socket.send(JSON.stringify(message));
}

后端代码：

public class WebSocketServer {
    public static void main(String[] args) {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new HttpServerCodec());
                            pipeline.addLast(new HttpObjectAggregator(65536));
                            pipeline.addLast(new WebSocketServerProtocolHandler("/"));
                            pipeline.addLast(new WebSocketServerHandler());
                        }
                    });

            ChannelFuture channelFuture = serverBootstrap.bind(8080).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

public class WebSocketServerHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
    private static final Map<String, Channel> channels = new ConcurrentHashMap<>();

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        channels.put(channel.id().asShortText(), channel);
    }

    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        channels.remove(channel.id().asShortText());
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
        String text = msg.text();
        JsonObject json = new Gson().fromJson(text, JsonObject.class);

        String type = json.get("type").getAsString();
        JsonObject data = json.get("data").getAsJsonObject();

        switch (type) {
            case "offer":
                handleOffer(ctx, data);
                break;
            case "answer":
                handleAnswer(ctx, data);
                break;
            case "candidate":
                handleCandidate(ctx, data);
                break;
            default:
                System.err.println("未知消息类型");
        }
    }

    private void handleOffer(ChannelHandlerContext ctx, JsonObject data) {
        String recipient = data.get("recipient").getAsString();
        Channel channel = channels.get(recipient);

        if (channel != null) {
            JsonObject offer = new JsonObject();
            offer.addProperty("type", "offer");
            offer.add("offer", data.get("offer"));

            channel.writeAndFlush(new TextWebSocketFrame(offer.toString()));
        }
    }

    private void handleAnswer(ChannelHandlerContext ctx, JsonObject data) {
        String recipient = data.get("recipient").getAsString();
        Channel channel = channels.get(recipient);

        if (channel != null) {
            JsonObject answer = new JsonObject();
            answer.addProperty("type", "answer");
            answer.add("answer", data.get("answer"));

            channel.writeAndFlush(new TextWebSocketFrame(answer.toString()));
        }
    }

    private void handleCandidate(ChannelHandlerContext ctx, JsonObject data) {
        String recipient = data.get("recipient").getAsString();
        Channel channel = channels.get(recipient);

        if (channel != null) {
            JsonObject candidate = new JsonObject();
            candidate.addProperty("type", "candidate");
            candidate.add("candidate", data.get("candidate"));

            channel.writeAndFlush(new TextWebSocketFrame(candidate.toString()));
        }
    }
}

注意：上面的代码只是一个简单的框架，还需要根据具体的业务需求进行修改和完善。