springboot接入netty实现在线统计人数

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>4.1.68.Final</version>
</dependency>

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class NettyServer {

    private final int port;
    
    public NettyServer(int port) {
        this.port = port;
    }
    
    public void run() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
                .channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new YourChannelHandler());
                    }
                });

            ChannelFuture f = b.bind(port).sync();
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        int port = 8888; // 配置服务器端口号
        new NettyServer(port).run(); // 启动服务器
    }
}

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

public class YourChannelHandler extends SimpleChannelInboundHandler<String> {
    
    // 维护在线人数的变量
    private static AtomicInteger onlineCount = new AtomicInteger(0);
    
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        onlineCount.incrementAndGet(); // 新的连接上线，增加在线人数
    }
    
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        onlineCount.decrementAndGet(); // 连接下线，减少在线人数
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        // 处理接收到的消息
        // ...
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class YourApplication {

    public static void main(String[] args) throws Exception {
        int nettyPort = 8888; // 配置 Netty 服务器端口号
        new NettyServer(nettyPort).run(); // 启动 Netty 服务器
        
        SpringApplication.run(YourApplication.class, args); // 启动 Spring Boot 应用
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class OnlineUserController {
    
    @GetMapping("/online-count")
    public int getOnlineCount() {
        return YourChannelHandler.onlineCount.get(); // 获取在线人数
    }
}