springboot集成netty服务端(TCP socket服务端)

netty依赖:

	<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
	
		io.netty
		netty-all
		4.1.28.Final
	

代码:

server启动类

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import java.net.InetSocketAddress;

/**
 * @description: netty服务启动类
 **/

@Slf4j
@Component
public class NettyServer {

    public void start(InetSocketAddress address) {
        //配置服务端的NIO线程组
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            ServerBootstrap bootstrap = new ServerBootstrap()
                    .group(bossGroup, workerGroup)  // 绑定线程池
                    .channel(NioServerSocketChannel.class)
                    .localAddress(address)
                    .childHandler(new NettyServerChannelInitializer())//编码解码
                    .option(ChannelOption.SO_BACKLOG, 128)  //服务端接受连接的队列长度，如果队列已满，客户端连接将被拒绝
                    .childOption(ChannelOption.SO_KEEPALIVE, true);  //保持长连接，2小时无数据激活心跳机制

            // 绑定端口，开始接收进来的连接
            ChannelFuture future = bootstrap.bind(address).sync();
            log.info("netty服务器开始监听端口：" + address.getPort());
            //关闭channel和块，直到它被关闭
            future.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

}

server初始化类

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

/**
 * @description: 服务端初始化，客户端与服务器端连接一旦创建，这个类中方法就会被回调，设置出站编码器和入站解码器
 **/

public class NettyServerChannelInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel channel) throws Exception {

        channel.pipeline().addLast("decoder",new StringDecoder(CharsetUtil.UTF_8));
        channel.pipeline().addLast("encoder",new StringEncoder(CharsetUtil.UTF_8));
        channel.pipeline().addLast(new NettyServerHandler());
    }
}

server处理类

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelId;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import java.net.InetSocketAddress;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @description: netty服务端处理类
 **/

@Slf4j
@Component
public class NettyServerHandler extends ChannelInboundHandlerAdapter {

    /**
     * 管理一个全局map，保存连接进服务端的通道数量
     */
    private static final ConcurrentHashMap<ChannelId, ChannelHandlerContext> CHANNEL_MAP = new ConcurrentHashMap<>();

   

    /**
     * @param ctx
     * @DESCRIPTION: 有客户端连接服务器会触发此函数
     * @return: void
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) {

        InetSocketAddress insocket = (InetSocketAddress) ctx.channel().remoteAddress();

        String clientIp = insocket.getAddress().getHostAddress();
        int clientPort = insocket.getPort();

        //获取连接通道唯一标识
        ChannelId channelId = ctx.channel().id();

        System.out.println();
        //如果map中不包含此连接，就保存连接
        if (CHANNEL_MAP.containsKey(channelId)) {
            log.info("客户端【" + channelId + "】是连接状态，连接通道数量: " + CHANNEL_MAP.size());
        } else {
            //保存连接
            CHANNEL_MAP.put(channelId, ctx);

            log.info("客户端【" + channelId + "】连接netty服务器[IP:" + clientIp + "--->PORT:" + clientPort + "]");
            log.info("连接通道数量: " + CHANNEL_MAP.size());
        }
    }

    /**
     * @param ctx
     * @DESCRIPTION: 有客户端终止连接服务器会触发此函数
     * @return: void
     */
    @Override
    public void channelInactive(ChannelHandlerContext ctx) {

        InetSocketAddress insocket = (InetSocketAddress) ctx.channel().remoteAddress();

        String clientIp = insocket.getAddress().getHostAddress();

        ChannelId channelId = ctx.channel().id();

        //包含此客户端才去删除
        if (CHANNEL_MAP.containsKey(channelId)) {
            //删除连接
            CHANNEL_MAP.remove(channelId);
            System.out.println();
            log.info("客户端【" + channelId + "】退出netty服务器[IP:" + clientIp + "--->PORT:" + insocket.getPort() + "]");
            log.info("连接通道数量: " + CHANNEL_MAP.size());
        }
    }

    /**
     * @param ctx
     * @DESCRIPTION: 有客户端发消息会触发此函数
     * @return: void
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

        String msgStr = String.valueOf(msg);

        System.out.println();
        log.info("加载客户端报文......");
        log.info("【" + ctx.channel().id() + "】" + " :" + msg);

   
        /**
         *  下面可以解析数据，保存数据，生成返回报文，将需要返回报文写入write函数
         *
         */

        //响应客户端
        log.info("服务端端返回报文......");
        log.info("【" + ctx.channel().id() + "】" + " :" + msg);
        this.channelWrite(ctx.channel().id(), msg);
    }

    /**
     * @param msg        需要发送的消息内容
     * @param channelId 连接通道唯一id
     * @DESCRIPTION: 服务端给客户端发送消息
     * @return: void
     */
    public void channelWrite(ChannelId channelId, Object msg) throws Exception {

        ChannelHandlerContext ctx = CHANNEL_MAP.get(channelId);

        if (ctx == null) {
            log.info("通道【" + channelId + "】不存在");
            return;
        }

        if (msg == null || msg == "") {
            log.info("服务端响应空的消息");
            return;
        }

        //将客户端的信息直接返回写入ctx
        ctx.write(msg);
        //刷新缓存区
        ctx.flush();
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {

        String socketString = ctx.channel().remoteAddress().toString();

        if (evt instanceof IdleStateEvent) {
            IdleStateEvent event = (IdleStateEvent) evt;
            if (event.state() == IdleState.READER_IDLE) {
                log.info("Client: " + socketString + " READER_IDLE 读超时");
                ctx.disconnect();
            } else if (event.state() == IdleState.WRITER_IDLE) {
                log.info("Client: " + socketString + " WRITER_IDLE 写超时");
                ctx.disconnect();
            } else if (event.state() == IdleState.ALL_IDLE) {
                log.info("Client: " + socketString + " ALL_IDLE 总超时");
                ctx.disconnect();
            }
        }
    }

    /**
     * @param ctx
     * @DESCRIPTION: 发生异常会触发此函数
     * @return: void
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {

        System.out.println();
        ctx.close();
        log.info(ctx.channel().id() + " 发生了错误,此连接被关闭" + "此时连通数量: " + CHANNEL_MAP.size());
        //cause.printStackTrace();
    }
}

启动类

在springboot启动类中加入服务端的启动代码，让netty服务跟着项目一起启动。

@Slf4j
@SpringBootApplication
@EnableAutoConfiguration(exclude={MongoAutoConfiguration.class})
public class JeecgSystemApplication extends SpringBootServletInitializer implements CommandLineRunner{

    @Value("${netty.port}")
    private Integer port;
    @Value("${netty.host}")
    private String host;

    @Autowired
    private NettyServer nettyServer;

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(JeecgSystemApplication.class);
    }

    public static void main(String[] args) throws UnknownHostException {
        ConfigurableApplicationContext application = SpringApplication.run(JeecgSystemApplication.class, args);
        Environment env = application.getEnvironment();
        String ip = InetAddress.getLocalHost().getHostAddress();
        String port = env.getProperty("server.port");
        String path = oConvertUtils.getString(env.getProperty("server.servlet.context-path"));
    }

    /**
     * netty服务启动
     * @param args
     * @throws Exception
     */
    @Override
    public void run(String... args) throws Exception {
        InetSocketAddress address = new InetSocketAddress(host,port);
        log.info("neety服务器启动地址: "+host+":"+ port);
        nettyServer.start(address);
    }
}

结束!