Springboot+yml+Netty4集成服务器端

我使用的是springboot+maven,所以先引入pom。（参考了网上的"许多"配置，然后自己做了一下修改）

在pom.xml中引用以下代码：

<dependency>
   <groupId>io.netty</groupId>
   <artifactId>netty-all</artifactId>
   <version>4.1.32.Final</version>
</dependency>

在application.yml中引用以下代码：

netty:
  tcp:
    server:
      host: 127.0.0.1
      port: 7000

然后创建文件NettyTcpServer.java
 

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 io.netty.util.concurrent.Future;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PreDestroy;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * description:
 * author:
 * date: 2018-11-28 12:07
 **/
@Component
public class NettyTcpServer {

    private static final Logger log = LoggerFactory.getLogger(NettyTcpServer.class);
    //boss事件轮询线程组
    //处理Accept连接事件的线程，这里线程数设置为1即可，netty处理链接事件默认为单线程，过度设置反而浪费cpu资源
    private EventLoopGroup boss = new NioEventLoopGroup(1);
    //worker事件轮询线程组
    //处理hadnler的工作线程，其实也就是处理IO读写 。线程数据默认为 CPU 核心数乘以2
    private EventLoopGroup worker = new NioEventLoopGroup();

    @Autowired
    ServerChannelInitializer serverChannelInitializer;

    @Value("${netty.tcp.server.port}")
    private Integer port;

    //与客户端建立连接后得到的通道对象
    private Channel channel;

    /**
     * 存储client的channel
     * key:ip，value:Channel
     */
    public static Map<String, Channel> map = new ConcurrentHashMap<String, Channel>();
    public static Map<String, String> macMap = new HashMap<String, String>();

    /**
     * 开启Netty tcp server服务
     *
     * @return
     */
    public ChannelFuture start() {
        //启动类
        ServerBootstrap serverBootstrap = new ServerBootstrap();
        serverBootstrap.group(boss, worker)//组配置，初始化ServerBootstrap的线程组
                .channel(NioServerSocketChannel.class)///构造channel通道工厂//bossGroup的通道，只是负责连接
                .childHandler(serverChannelInitializer)//设置通道处理者ChannelHandler////workerGroup的处理器
                .option(ChannelOption.SO_BACKLOG, 1024)
//                .option(ChannelOption.MAX_MESSAGES_PER_READ, Integer.MAX_VALUE)//socket参数，当服务器请求处理程全满时，用于临时存放已完成三次握手请求的队列的最大长度。如果未设置或所设置的值小于1，Java将使用默认值50。
                .childOption(ChannelOption.SO_KEEPALIVE, true);//启用心跳保活机制，tcp
        //Future：异步任务的生命周期，可用来获取任务结果
        ChannelFuture channelFuture1 = serverBootstrap.bind(port).syncUninterruptibly();//绑定端口，开启监听，同步等待
        if (channelFuture1 != null && channelFuture1.isSuccess()) {
            channel = channelFuture1.channel();//获取通道
            log.info("Netty tcp server start success, port = {}", port);
        } else {
            log.error("Netty tcp server start fail");
        }
        return channelFuture1;
    }

    /**
     * 停止Netty tcp server服务
     */
    @PreDestroy
    public void destroy() {
        if (channel != null) {
            channel.close();
        }
        try {
            Future<?> future = worker.shutdownGracefully().await();
            if (!future.isSuccess()) {
                log.error("netty tcp workerGroup shutdown fail, {}", future.cause());
            }
            Future<?> future1 = boss.shutdownGracefully().await();
            if (!future1.isSuccess()) {
                log.error("netty tcp bossGroup shutdown fail, {}", future1.cause());
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        log.info("Netty tcp server shutdown success");
    }

}

然后创建ServerChannelHandler.java文件

@Component
@ChannelHandler.Sharable
public class ServerChannelHandler extends ChannelDuplexHandler {

    private static Logger logger = LoggerFactory.getLogger(ServerChannelHandler.class);

    @Autowired
    private SelfLogsService selfLogService;

    @Autowired
    private SelfUserService selfUserService;
    @Autowired
    private SelfUserDeviceService selfUserDeviceService;

    /**
     * 拿到传过来的msg数据，开始处理
     *
     * @param ctx
     * @param msg
     * @throws Exception
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println("Netty tcp server receive msg : " + msg);
        ctx.channel().writeAndFlush(" response msg ").syncUninterruptibly();//发送数据，异步任务
    }

    /**
     * 活跃的、有效的通道
     * 第一次连接成功后进入的方法
     *
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        super.channelActive(ctx);
        logger.info("tcp client " + getRemoteAddress(ctx) + " connect success");
        //往channel map中添加channel信息
        NettyTcpServer.map.put(getIPString(ctx), ctx.channel());
    }

    /**
     * 不活动的通道
     * 连接丢失后执行的方法（client端可据此实现断线重连）
     *
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        //删除Channel Map中的失效Client
        NettyTcpServer.map.remove(getIPString(ctx));
        NettyTcpServer.macMap.remove(getIPString(ctx));
        ctx.close();
    }

    /**
     * 心跳机制，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) {
                logger.info("Client: " + socketString + " READER_IDLE 读超时");
                ctx.disconnect();//断开
            } else if (event.state() == IdleState.WRITER_IDLE) {
                logger.info("Client: " + socketString + " WRITER_IDLE 写超时");
                ctx.disconnect();
            } else if (event.state() == IdleState.ALL_IDLE) {
                logger.info("Client: " + socketString + " ALL_IDLE 总超时");
                ctx.disconnect();
            }
        }
    }

    /**
     * 获取client对象：ip+port
     *
     * @param ctx
     * @return
     */
    public String getRemoteAddress(ChannelHandlerContext ctx) {
        String socketString = "";
        socketString = ctx.channel().remoteAddress().toString();
        return socketString;
    }

    /**
     * 获取client的ip
     *
     * @param ctx
     * @return
     */
    public String getIPString(ChannelHandlerContext ctx) {
        String ipString = "";
        String socketString = ctx.channel().remoteAddress().toString();
        int colonAt = socketString.indexOf(":");
        ipString = socketString.substring(1, colonAt);
        return ipString;
    }

创建ServerChannelInitializer.java文件

/**
 * description: 通道初始化，主要用于设置各种Handler
 * author:
 * date: 2018-11-28 14:55
 **/
@Component
public class ServerChannelInitializer extends ChannelInitializer<SocketChannel> {

    @Autowired
    ServerChannelHandler serverChannelHandler;

    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        ChannelPipeline pipeline = socketChannel.pipeline();
        //IdleStateHandler心跳机制,如果超时触发Handle中userEventTrigger()方法
        pipeline.addLast("idleStateHandler",
                new IdleStateHandler(5, 0, 0, TimeUnit.MINUTES));
        //字符串编解码器

        pipeline.addLast(
                new StringDecoder(),
                new StringEncoder()
        );
        pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 4, 4, -8, 0));
//        pipeline.addLast("byteArrayEncoder", new ByteArrayEncoder());

        //自定义Handler
        pipeline.addLast("serverChannelHandler", serverChannelHandler);
    }
}

至此，大工告成，因为我自己修改的配置地方不多。