netty实现服务端和客户端交互

系列文章目录

Netty是由JBOSS提供的一个java开源框架，现为 Github上的独立项目。Netty提供异步的、事件驱动的网络应用程序框架和工具，用以快速开发高性能、高可靠性的网络服务器和客户端程序。

---

---

前言

提示：学习netty要有nio的基础

---

一、上代码

1.引入库

代码如下（示例）：

<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
		<dependency>
			<groupId>io.netty</groupId>
			<artifactId>netty-all</artifactId>
			<version>4.1.80.Final</version>
		</dependency>

2.服务端

代码如下（示例）：NettyServer

package netty;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

/**
 * Create by zjg on 2022/9/12
 */
public class NettyServer {
    public static void main(String[] args) {
        NioEventLoopGroup bossGroup = null;
        NioEventLoopGroup workGroup= null;
        try {
            bossGroup=new NioEventLoopGroup();
            workGroup=new NioEventLoopGroup();
            ServerBootstrap bootstrap=new ServerBootstrap();
            bootstrap.group(bossGroup,workGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG,128)
                    .childOption(ChannelOption.SO_KEEPALIVE,true)
                    .childHandler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(Channel channel) throws Exception {
                            channel.pipeline().addLast(new NettyServerHandler());
                        }
                    });
            ChannelFuture channelFuture = bootstrap.bind(8080).sync();
            System.out.println("服务端启动完成!");
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}

代码如下（示例）：NettyServerHandler

package netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 * Create by zjg on 2022/9/12
 */
public class NettyServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf byteBuf= (ByteBuf) msg;
        String req=byteBuf.toString(CharsetUtil.UTF_8);
        System.out.println("接收到客户端请求:"+req);
        String res= "服务器响应["+ LocalDateTime.now().format(DateTimeFormatter.ISO_DATE)+" "+LocalDateTime.now().format(DateTimeFormatter.ISO_TIME)+"]:"+req+"--YYDS";
        System.out.println("服务端响应:"+res);
        ctx.writeAndFlush(Unpooled.copiedBuffer(res,CharsetUtil.UTF_8));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        System.out.println("异常");
        cause.printStackTrace();
        ctx.close();
    }
}

3.客户端

代码如下（示例）：NettyClient

package netty;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * Create by zjg on 2022/9/12
 */
public class NettyClient {
    public static void main(String[] args) {
        NioEventLoopGroup nioEventLoopGroup=null;
        try {
            nioEventLoopGroup=new NioEventLoopGroup();
            Bootstrap bootstrap=new Bootstrap();
            bootstrap.group(nioEventLoopGroup)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {
                            socketChannel.pipeline().addLast(new NettyClientHandler());
                        }
                    });
            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1", 8080).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            nioEventLoopGroup.shutdownGracefully();
        }

    }
}

代码如下（示例）：NettyClientHandler

package netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

/**
 * Create by zjg on 2022/9/12
 */
public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(Unpooled.copiedBuffer("扣鸡摩托，扎西得嘞!",CharsetUtil.UTF_8));
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf byteBuf= (ByteBuf) msg;
        System.out.println("接收到服务端响应:"+byteBuf.toString(CharsetUtil.UTF_8));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

---

总结

友情链接