本文共 4540 字，大约阅读时间需要 15 分钟。

关于Netty，可以看做是对JDK的nio API的封装，提供了更简单的实现，同时性能，功能更加丰富以及相对应的安全机制，对于Netty的学习，大家可以访问如下网址，里面讲解的很详细，这里仅写一个小demo作为入门。

学习网址：http://ifeve.com/netty5-user-guide/

server：

package 网络编程_Netty;import io.netty.bootstrap.ServerBootstrap;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;public class Server {	private int port;	public Server(int port){		this.port = port;	}	public void run() throws Exception{		/*定义两个处理IO操作的多线程时间循环器，boss一般用来接受客户端连接，workers用来处理已经被接		收的连接，这里使用NIOEvent处理tcp协议，还有很多种实现类用于处理不同的传输协议。		*/		EventLoopGroup boss = new NioEventLoopGroup();		EventLoopGroup workers = new NioEventLoopGroup();		try {			//ServerBootstrap是服务端的启动NIO服务的辅助类，用于设置一些服务的参数			ServerBootstrap bootstrap = new ServerBootstrap();			//将两个事件循环器加入到辅助类中			bootstrap.group(boss, workers)					//指定具体的通道连接方式					 .channel(NioServerSocketChannel.class)					 //使用childHandler指定具体的事件处理类					 .childHandler(new ChannelInitializer
   
    () {						@Override						public void initChannel(SocketChannel ch) throws Exception {							ch.pipeline().addLast(new ServerHandler());						}					 })					 //关闭BACKLOG参数作用需要了解TCP底层三次握手机制，底部维持了2个队列，当两个队列和大于BACKLOG时，服务端会拒绝客户端连接					 .option(ChannelOption.SO_BACKLOG, 128)					 //保持存活状态					 .childOption(ChannelOption.SO_KEEPALIVE, true);			ChannelFuture f = bootstrap.bind(port).sync();//绑定端口			f.channel().closeFuture().sync();//相当于阻塞		} finally {			workers.shutdownGracefully();//关闭操作			boss.shutdownGracefully();		}	}	public static void main(String[] args) throws Exception{		new Server(8888).run();	}}
   

package 网络编程_Netty;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelFutureListener;import io.netty.channel.ChannelHandlerAdapter;import io.netty.channel.ChannelHandlerContext;/** * 处理器类，处理器是由netty生成用来处理IO事件的 * @author lihao * */public class ServerHandler extends ChannelHandlerAdapter{	@Override	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {		cause.printStackTrace();		ctx.close();	}	@Override	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {			ByteBuf buf = (ByteBuf)msg;			byte[] bys = new byte[buf.readableBytes()];			buf.readBytes(bys);			String accept = new String(bys,"utf-8");			System.out.println(accept);			String response = new String("你好，服务器已经接受到你的请求");			ChannelFuture writeAndFlush = ctx.writeAndFlush(Unpooled.copiedBuffer(response.getBytes()));//wirte的时候会手动的释放msg			writeAndFlush.addListener(ChannelFutureListener.CLOSE);//监听写数据进程，当数据写出完毕关闭连接	}	}

package 网络编程_Netty;import io.netty.bootstrap.Bootstrap;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelInitializer;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 Client {	public static void main(String[] args) throws Exception {		EventLoopGroup workers = new NioEventLoopGroup();		Bootstrap bootstrap = new Bootstrap();		bootstrap.group(workers)				 .channel(NioSocketChannel.class)				 .handler(new ChannelInitializer
   
    () {					@Override					protected void initChannel(SocketChannel ch) throws Exception {						ch.pipeline().addLast(new ClientHandler());					}				});				ChannelFuture f = bootstrap.connect("127.0.0.1",8888).sync();				f.channel().writeAndFlush(Unpooled.copiedBuffer("hello netty".getBytes()));				f.channel().closeFuture().sync();				workers.shutdownGracefully();	}}
   

package 网络编程_Netty;import io.netty.buffer.ByteBuf;import io.netty.channel.ChannelHandlerAdapter;import io.netty.channel.ChannelHandlerContext;import io.netty.util.ReferenceCountUtil;public class ClientHandler extends ChannelHandlerAdapter{	@Override	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {		cause.printStackTrace();		ctx.close();	}	@Override	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {				try {			ByteBuf buf = (ByteBuf)msg;			byte[] bys = new byte[buf.readableBytes()];			buf.readBytes(bys);			String accept = new String(bys,"utf-8");			System.out.println(accept);		} finally {			ReferenceCountUtil.release(msg);		}			}	}

转载地址：https://blog.csdn.net/Lee_Ho_/article/details/78128340 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！