springboot netty 搭建

maven

 
            io.netty
            netty-all
            4.1.36.Final
        

废话不说代码奉上(感觉有用的点个赞可好)

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
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.boot.CommandLineRunner;
import org.springframework.core.annotation.Order;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;
import javax.annotation.PreDestroy;
import java.net.InetSocketAddress;

/**
 * 

 * 服务启动监听器
 **/
@Slf4j
@Component//当成组件处理
@Order(value = 1)//这里表示启动顺序
public class NettyServer implements CommandLineRunner {

    /**
     * 配置服务端的NIO线程组
     * NioEventLoopGroup 是用来处理I/O操作的Reactor线程组
     * bossGroup：用来接收进来的连接，workerGroup：用来处理已经被接收的连接,进行socketChannel的网络读写，
     * bossGroup接收到连接后就会把连接信息注册到workerGroup
     * workerGroup的EventLoopGroup默认的线程数是CPU核数的二倍
     */
    EventLoopGroup bossGroup = new NioEventLoopGroup(1);
    //new 一个工作线程组  专门负责网络读写操作
    EventLoopGroup workGroup = new NioEventLoopGroup(200);

    private Channel channel;

    public void start(InetSocketAddress socketAddress) {
        ChannelFuture future = null;
        ServerBootstrap bootstrap = new ServerBootstrap()
                .group(bossGroup, workGroup)
                .channel(NioServerSocketChannel.class)
                .childHandler(new ServerChannelInitializer())
                .localAddress(socketAddress)
                //设置队列大小
                .option(ChannelOption.SO_BACKLOG, 2048)
                //关闭延迟发送
                .childOption(ChannelOption.TCP_NODELAY, true)
                // 两小时内没有数据的通信时,TCP会自动发送一个活动探测数据报文
                .childOption(ChannelOption.SO_KEEPALIVE, true);
        try {
            //绑定端口,开始接收进来的连接
            future = bootstrap.bind(socketAddress).sync();
            log.info("服务器启动开始监听端口: {}", socketAddress.getPort());
            channel = future.channel();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @PreDestroy
    public void destroy() {
        if (channel != null) {
            log.info("Netty Server close");
            channel.close();
            workGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
        log.info("关闭成功");
    }

    public Channel getChannel() {
        return channel;
    }

    @Async//注意这里，组件启动时会执行run，这个注解是让线程异步执行，这样不影响主线程
    @Override
    public void run(String... args) throws Exception {
        start(new InetSocketAddress(6789));
    }
}

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.CharsetUtil;


/**
 *
 * netty服务初始化器
 **/
public class ServerChannelInitializer extends ChannelInitializer {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        // 这里使用的是自定义分隔符作为 ，防止 数据粘包问题 分包
        ByteBuf delimiter = Unpooled.copiedBuffer(">###".getBytes());
        socketChannel.pipeline()
                .addLast(new DelimiterBasedFrameDecoder(1024*1024,delimiter))
                //三十秒没有收到消息 将IdleStateHandler 添加到 ChannelPipeline 中
                .addLast(new IdleStateHandler(30, 0, 0))//(8)
                // 往pipeline链中添加一个编码器,字符串->二进制
                .addLast("encoder", new StringEncoder(CharsetUtil.US_ASCII))
                // 往pipeline链中添加一个解码器
                .addLast("decoder", new StringDecoder(CharsetUtil.US_ASCII))
                .addLast(new NettyServerHandler())
        ;
    }
}

import io.netty.channel.ChannelFutureListener;
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 java.net.InetSocketAddress;
import java.util.concurrent.ConcurrentHashMap;

import static io.netty.handler.codec.stomp.StompHeaders.HEART_BEAT;

/**
 * 

 * netty服务端处理器
 **/

@Slf4j
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 CHANNEL_MAP = new ConcurrentHashMap<>();



    public void sendOne(){

    }

    /**
     * 客户端连接会触发
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        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());
        }

    }


    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        delectChannel(ctx);
    }



    /**
     * 客户端发消息会触发
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println();
        log.info("加载客户端报文......");
        log.info("【" + ctx.channel().id() + "】" + " :" + msg);

        //响应客户端
        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
     * @author xiongchuan on 2019/4/28 16:10
     * @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;
        }
        //将客户端的信息直接返回写入ctx
        ctx.write(msg);
        //刷新缓存区
        ctx.flush();
    }



    /**
     * 超时处理
     *
     * @param ctx
     * @param evt
     * @throws Exception
     */
    @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");
                this.channelWrite(ctx.channel().id(), "超时服务器断开".getBytes());
                ctx.disconnect();
                ctx.writeAndFlush(HEART_BEAT).addListener(ChannelFutureListener.CLOSE_ON_FAILURE) ;
            } else if (event.state() == IdleState.WRITER_IDLE) {
                log.info("Client: " + socketString + " WRITER_IDLE 写超时");
                this.channelWrite(ctx.channel().id(), "超时服务器断开".getBytes());
                ctx.disconnect();
            } else if (event.state() == IdleState.ALL_IDLE) {
                log.info("Client: " + socketString + " ALL_IDLE 总超时");
                this.channelWrite(ctx.channel().id(), "超时服务器断开".getBytes());
                ctx.disconnect();
            }
        }
    }


    /**
     * 发生异常触发
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        // 当出现异常就关闭连接
        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());
        delectChannel(ctx);
        ctx.close();
    }

    /**
     * 断开移除
     * @param ctx
     */
    public void delectChannel(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);
            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());
        }
    }

}