Netty实现简单的Socket通讯_Touch&的博客-CSDN博客_netty socket

安宇雨 - 随手采集
2022-07-14 15:04:22
随手采集
0000-未整理-等待研究

Netty实现简单的Socket通讯

Netty简介

Netty是由JBOSS提供的一个java开源框架。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。也就是说，Netty 是一个基于NIO的客户、服务器端编程框架，使用Netty 可以确保你快速和简单的开发出一个网络应用，例如实现了某种协议的客户，服务端应用。Netty相当简化和流线化了网络应用的编程开发过程，例如，TCP和UDP的socket服务开发。

Netty 是一个吸收了多种协议的实现经验，这些协议包括FTP,SMTP,HTTP，各种二进制，文本协议，并经过相当精心设计的项目，最终，Netty 成功的找到了一种方式，在保证易于开发的同时还保证了其应用的性能，稳定性和伸缩性。

本文目的

使用Netty实现一个Socket通讯，包括客户端和服务端，通过服务端进行监听，客户端发送信息，服务端可进行接收，并进行返回数据，完成一个完整的通讯。

依赖引入：

 implementation 'io.netty:netty-all:4.1.43.Final'

<dependency>      <groupId>io.netty</groupId>      <artifactId>netty-all</artifactId>      <version>4.1.43.Final</version></dependency>

服务端编码

a.MyService.java

import io.netty.bootstrap.ServerBootstrap;import io.netty.channel.ChannelFuture;import io.netty.channel.EventLoopGroup;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioServerSocketChannel; public class MyServer {    public static void main(String[] args) {        //循环组接收连接，不进行处理,转交给下面的线程组        EventLoopGroup bossGroup = new NioEventLoopGroup();        //循环组处理连接，获取参数，进行工作处理        EventLoopGroup workerGroup = new NioEventLoopGroup();        try {            //服务端进行启动类            ServerBootstrap serverBootstrap = new ServerBootstrap();            //使用NIO模式，初始化器等等            serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new MyServerInitializer());            //绑定端口            ChannelFuture channelFuture = serverBootstrap.bind(9008).sync();            channelFuture.channel().closeFuture().sync();        } catch (InterruptedException e) {            e.printStackTrace();        } finally {            bossGroup.shutdownGracefully();            workerGroup.shutdownGracefully();        }    }}

b.MyServerInitializer.java

import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.socket.SocketChannel;import io.netty.handler.codec.LengthFieldBasedFrameDecoder;import io.netty.handler.codec.LengthFieldPrepender;import io.netty.handler.codec.string.StringDecoder;import io.netty.handler.codec.string.StringEncoder;import io.netty.util.CharsetUtil; public class MyServerInitializer extends ChannelInitializer<SocketChannel> {     //连接注册，创建成功，会被调用    @Override    protected void initChannel(SocketChannel ch) throws Exception {        ChannelPipeline pipeline = ch.pipeline();        pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4));        pipeline.addLast(new LengthFieldPrepender(4));        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));        pipeline.addLast(new MyServerHandler());    }}

c.MyServerHandler.java

import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory; import java.util.UUID; public class MyServerHandler extends SimpleChannelInboundHandler<String> {     private Log LOGGER = LogFactory.getLog(MyServerHandler.class);      @Override    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {        LOGGER.info(ctx.channel().remoteAddress() + "," + msg);        ctx.channel().writeAndFlush("from service:" + UUID.randomUUID());    }      @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {        cause.getCause();        ctx.channel().close();    }}

客户端编码

a.MyClient

import io.netty.bootstrap.Bootstrap;import io.netty.channel.ChannelFuture;import io.netty.channel.EventLoopGroup;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioSocketChannel; public class MyClient {    public static void main(String[] args) {        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();        try {            Bootstrap bootstrap = new Bootstrap();            bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class).handler(new MyClientInitializer());            //绑定服务器            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1", 9008).sync();            channelFuture.channel().closeFuture().sync();        } catch (Exception e) {            e.printStackTrace();            eventLoopGroup.shutdownGracefully();        }    }}

b.MyClientInitializer.java

import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.socket.SocketChannel;import io.netty.handler.codec.LengthFieldBasedFrameDecoder;import io.netty.handler.codec.LengthFieldPrepender;import io.netty.handler.codec.string.StringDecoder;import io.netty.handler.codec.string.StringEncoder;import io.netty.util.CharsetUtil; public class MyClientInitializer extends ChannelInitializer<SocketChannel> {     //连接注册，创建成功，会被调用    @Override    protected void initChannel(SocketChannel ch) throws Exception {        System.out.println("initChannel");        ChannelPipeline pipeline = ch.pipeline();        pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4));        pipeline.addLast(new LengthFieldPrepender(4));        //编解码        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));        pipeline.addLast(new MyClientHandler());    } }

c.MyClientHandler.java

import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory; import java.time.LocalDateTime; public class MyClientHandler extends SimpleChannelInboundHandler<String> {     private Log LOGGER = LogFactory.getLog(MyClientHandler.class);      @Override    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {        LOGGER.info(ctx.channel().remoteAddress());        LOGGER.info("client output:" + msg);        ctx.writeAndFlush("from client:" + LocalDateTime.now());    }     @Override    public void channelActive(ChannelHandlerContext ctx) throws Exception {        ctx.channel().writeAndFlush("来自客户端的问候！");    }     @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {        cause.printStackTrace();        ctx.channel().close();    }}

启动测试