public class TCPServer {     private Logger log = LoggerFactory.getLogger(getClass());     //端口号    private int port=5080;     //服务器运行状态    private volatile boolean isRunning = false;      //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 final EventLoopGroup bossGroup = new NioEventLoopGroup(1);     //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 final EventLoopGroup workerGroup = new NioEventLoopGroup();           public void init() throws Exception{         //创建ServerBootstrap实例        ServerBootstrap serverBootstrap=new ServerBootstrap();         //初始化ServerBootstrap的线程组        serverBootstrap.group(workerGroup,workerGroup);//        //设置将要被实例化的ServerChannel类        serverBootstrap.channel(NioServerSocketChannel.class);//        //在ServerChannelInitializer中初始化ChannelPipeline责任链，并添加到serverBootstrap中        serverBootstrap.childHandler(new ServerChannelInitializer());         //标识当服务器请求处理线程全满时，用于临时存放已完成三次握手的请求的队列的最大长度        serverBootstrap.option(ChannelOption.SO_BACKLOG, 1024);         // 是否启用心跳保活机机制        serverBootstrap.childOption(ChannelOption.SO_KEEPALIVE, true);             //绑定端口后，开启监听        ChannelFuture channelFuture = serverBootstrap.bind(port).sync();         if(channelFuture.isSuccess()){             System.out.println("TCP服务启动 成功---------------");         }     }          /**      * 服务启动      */    public synchronized void startServer() {         try {               this.init();         }catch(Exception ex) {                      }     }          /**      * 服务关闭      */    public synchronized void stopServer() {         if (!this.isRunning) {             throw new IllegalStateException(this.getName() + " 未启动 .");         }         this.isRunning = false;         try {             Future<?> future = this.workerGroup.shutdownGracefully().await();             if (!future.isSuccess()) {                 log.error("workerGroup 无法正常停止:{}", future.cause());             }              future = this.bossGroup.shutdownGracefully().await();             if (!future.isSuccess()) {