package simpleDialogServer;import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;  public class HelloServer {  public void start(int port) throws Exception {  EventLoopGroup bossGroup = new NioEventLoopGroup();  EventLoopGroup workerGroup = new NioEventLoopGroup();  try {  ServerBootstrap b = new ServerBootstrap();  b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)  .childHandler(new ChannelInitializer<SocketChannel>() {  @Override  public void initChannel(SocketChannel ch)  throws Exception {  // 注册handler  ch.pipeline().addLast(new HelloServerInHandler());  }  }).option(ChannelOption.SO_BACKLOG, 128)  .childOption(ChannelOption.SO_KEEPALIVE, true);  ChannelFuture f = b.bind(port).sync();  f.channel().closeFuture().sync();  } finally {  workerGroup.shutdownGracefully();  bossGroup.shutdownGracefully();  }  }  public static void main(String[] args) throws Exception {  HelloServer server = new HelloServer();  server.start(8000);  }
}// 该handler是InboundHandler类型
class HelloServerInHandler extends ChannelInboundHandlerAdapter {  @Override  public void channelRead(ChannelHandlerContext ctx, Object msg)  throws Exception {  ByteBuf result = (ByteBuf) msg;  byte[] result1 = new byte[result.readableBytes()];  // msg中存储的是ByteBuf类型的数据，把数据读取到byte[]中
        result.readBytes(result1);  String resultStr = new String(result1);  // 接收并打印客户端的信息  System.out.println("Client said:" + resultStr);  // 释放资源，这行很关键
        result.release();  // 向客户端发送消息  String response = "I am ok!";  // 在当前场景下，发送的数据必须转换成ByteBuf数组  ByteBuf encoded = ctx.alloc().buffer(4 * response.length());  encoded.writeBytes(response.getBytes());  ctx.write(encoded);  ctx.flush();  }  @Override  public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {  ctx.flush();ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);}
}  

package simpleDialogClient;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;  public class HelloClient {  public void connect(String host, int port) throws Exception {  EventLoopGroup workerGroup = new NioEventLoopGroup();  try {  Bootstrap b = new Bootstrap();  b.group(workerGroup);  b.channel(NioSocketChannel.class);  b.option(ChannelOption.SO_KEEPALIVE, true);  b.handler(new ChannelInitializer<SocketChannel>() {  @Override  public void initChannel(SocketChannel ch) throws Exception {  ch.pipeline().addLast(new HelloClientIntHandler());  }  });  // Start the client.  ChannelFuture f = b.connect(host, port).sync();  // Wait until the connection is closed.
          f.channel().closeFuture().sync();  } finally {  workerGroup.shutdownGracefully();  }  }  public static void main(String[] args) throws Exception {  HelloClient client = new HelloClient();  client.connect("127.0.0.1", 8000);  }
}
class HelloClientIntHandler extends ChannelInboundHandlerAdapter {  // 接收server端的消息，并打印出来
    @Override  public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {  ByteBuf result = (ByteBuf) msg;  byte[] result1 = new byte[result.readableBytes()];  result.readBytes(result1);  System.out.println("Server said:" + new String(result1));  result.release();  }  // 连接成功后，向server发送消息
    @Override  public void channelActive(ChannelHandlerContext ctx) throws Exception {  String msg = "Are you ok?";  ByteBuf encoded = ctx.alloc().buffer(4 * msg.length());  encoded.writeBytes(msg.getBytes());  ctx.write(encoded);  ctx.flush();  }
}