Netty学习教程之基础使用篇

import io.netty.bootstrap.ServerBootstrap; 
import io.netty.buffer.ByteBuf; 
import io.netty.buffer.Unpooled; 
import io.netty.channel.ChannelFuture; 
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.handler.codec.DelimiterBasedFrameDecoder; 
import io.netty.handler.codec.string.StringDecoder; 
 
public class Server { 
  
 public static void main(String[] args) throws InterruptedException { 
  //1.第一个线程组是用于接收Client端连接的 
  EventLoopGroup bossGroup = new NioEventLoopGroup(); 
  //2.第二个线程组是用于实际的业务处理的 
  EventLoopGroup workerGroup = new NioEventLoopGroup(); 
  ServerBootstrap b = new ServerBootstrap(); 
  b.group(bossGroup, workerGroup);//绑定两个线程池 
  b.channel(NioServerSocketChannel.class);//指定NIO的模式，如果是客户端就是NioSocketChannel 
  b.option(ChannelOption.SO_BACKLOG, 1024);//TCP的缓冲区设置 
  b.option(ChannelOption.SO_SNDBUF, 32*1024);//设置发送缓冲的大小 
  b.option(ChannelOption.SO_RCVBUF, 32*1024);//设置接收缓冲区大小 
  b.option(ChannelOption.SO_KEEPALIVE, true);//保持连续 
  b.childHandler(new ChannelInitializer<SocketChannel>() { 
   @Override 
   protected void initChannel(SocketChannel sc) throws Exception { 
    ByteBuf buf = Unpooled.copiedBuffer("$_".getBytes());//拆包粘包定义结束字符串（第一种解决方案） 
    sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024,buf));//在管道中加入结束字符串 
   // sc.pipeline().addLast(new FixedLengthFrameDecoder(200));第二种定长 
    sc.pipeline().addLast(new StringDecoder());//定义接收类型为字符串把ByteBuf转成String 
    sc.pipeline().addLast(new ServertHandler());//在这里配置具体数据接收方法的处理 
   } 
  }); 
  ChannelFuture future = b.bind(8765).sync();//绑定端口 
  future.channel().closeFuture().sync();//等待关闭(程序阻塞在这里等待客户端请求) 
  bossGroup.shutdownGracefully();//关闭线程 
  workerGroup.shutdownGracefully();//关闭线程 
 } 
} 

public class ServertHandler extends ChannelHandlerAdapter { 
 
 @Override 
 public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
  String body = (String) msg; 
  System.out.println("server"+body);//前面已经定义了接收为字符串，这里直接接收字符串就可以 
  //服务端给客户端的响应 
  String response= " hi client!$_";//发送的数据以定义结束的字符串结尾 
  ctx.writeAndFlush(Unpooled.copiedBuffer(response.getBytes()));//发送必须还是ByteBuf类型 
 } 
 
 @Override 
 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { 
   cause.printStackTrace(); 
   ctx.close(); 
 } 
  
} 

public class Client { 
 
 public static void main(String[] args) throws InterruptedException { 
  EventLoopGroup worker = new NioEventLoopGroup(); 
  Bootstrap b = new Bootstrap(); 
  b.group(worker) 
  .channel(NioSocketChannel.class) 
  .handler(new ChannelInitializer<SocketChannel>() { 
   @Override 
   protected void initChannel(SocketChannel sc) throws Exception { 
    ByteBuf buf = Unpooled.copiedBuffer("$_".getBytes()); 
    sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024,buf)); 
    sc.pipeline().addLast(new StringDecoder()); 
    sc.pipeline().addLast(new ClientHandler()); 
   } 
  }); 
  ChannelFuture f=b.connect("127.0.0.1",8765).sync(); 
  f.channel().writeAndFlush(Unpooled.copiedBuffer(" hi server2$_".getBytes())); 
  f.channel().writeAndFlush(Unpooled.copiedBuffer(" hi server3$_".getBytes())); 
  f.channel().writeAndFlush(Unpooled.copiedBuffer(" hi server4$_".getBytes())); 
  f.channel().closeFuture().sync(); 
  worker.shutdownGracefully(); 
 } 
} 

public class ClientHandler extends ChannelHandlerAdapter{ 
 @Override 
 public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
  try { 
   System.out.println("client"+msg.toString()); 
  } finally { 
   ReferenceCountUtil.release(msg);//释放缓冲区 
  } 
 } 
 
 @Override 
 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { 
   cause.printStackTrace(); 
   ctx.close(); 
 } 
}