content: package splicing.linebase;
  
  import constant.Constant;
  import io.netty.bootstrap.ServerBootstrap;
  import io.netty.channel.*;
  import io.netty.channel.nio.NioEventLoopGroup;
  import io.netty.channel.socket.nio.NioServerSocketChannel;
  import io.netty.handler.codec.LineBasedFrameDecoder;
  
  import java.net.InetSocketAddress;
  
  public class LineBaseEchoServer {
  
      public static void main(String[] args) throws InterruptedException {
          LineBaseEchoServer lineBaseEchoServer = new LineBaseEchoServer();
          System.out.println("服务器即将启动");
          lineBaseEchoServer.start();
      }
      
      public void start() throws InterruptedException {
          LineBaseServerHandler serverHandler = new LineBaseServerHandler();
          
          EventLoopGroup group = new NioEventLoopGroup();// 线程组
          try {
              // 服务端启动必须
              ServerBootstrap b = new ServerBootstrap();
              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(Constant.DEFAULT_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handler
                      .childHandler(new ChannelInitializerImp());
  
  
              // 异步绑定到服务器，sync()会阻塞直到完成
              ChannelFuture f = b.bind().sync();
              // 我们可以为这个ChannelFuture增加监听器，当它有回调结果的时候通知channelFutureListener
              f.addListener(new ChannelFutureListener() {
                  @Override
                  public void operationComplete(ChannelFuture future) throws Exception {
                      System.out.println("服务器端绑定已经完成");
                  }
              });
  
              System.out.println("服务器启动完成,等待客户端的连接和数据......");
              // 阻塞直到服务器的channel关闭
              f.channel().closeFuture().sync();
  
          }finally {
              group.shutdownGracefully().sync();
          }
      }
      
      private static class ChannelInitializerImp extends ChannelInitializer<Channel> {
  
          @Override
          protected void initChannel(Channel ch) throws Exception {
              ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
              ch.pipeline().addLast(new LineBaseServerHandler());
          }
      }
  }
  