EchoServer

EchoServer

public class EchoServer  {
    private final int port;
    public EchoServer(int port) {
        this.port = port;
    }
    public static void main(String[] args) throws InterruptedException {
        EchoServer echoServer = new EchoServer(9999);
        System.out.println("服务器即将启动");
        echoServer.start();
        System.out.println("服务器关闭");
    }
    public void start() throws InterruptedException {
        final EchoServerHandler serverHandler = new EchoServerHandler();
        EventLoopGroup group = new NioEventLoopGroup();/*线程组*/
        try {
            ServerBootstrap b = new ServerBootstrap();/*服务端启动必须*/
            b.group(group)/*将线程组传入*/
                .channel(NioServerSocketChannel.class)/*指定使用NIO进行网络传输*/
                .localAddress(new InetSocketAddress(port))/*指定服务器监听端口*/
                /*服务端每接收到一个连接请求，就会新启一个socket通信，也就是channel，
                所以下面这段代码的作用就是为这个子channel增加handle*/
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline().addLast(serverHandler);/*添加到该子channel的pipeline的尾部*/
                    }
                });
            ChannelFuture f = b.bind().sync();/*异步绑定到服务器，sync()会阻塞直到完成*/
            System.out.println("服务器启动完成，等待客户端的连接和数据.....");
            f.channel().closeFuture().sync();/*阻塞直到服务器的channel关闭*/
        } finally {
            group.shutdownGracefully().sync();/*优雅关闭线程组*/
        }
    }
}