哪里可以做网站啊,网站搭建免费视频教程,电子商务网站建设策划方案,企业画册设计模板文章目录 1 摘要2 核心 Maven 依赖3 核心代码3.1 服务端事务处理器 (DemoNettyServerHandler)3.2 服务端连接类(InitNettyServer)3.3 客户端事务处理器(DemoNettyClientHandler)3.4 客户端连接类(DemoNettyClient) 4 测试4.1 测试流程4.2 测试结果4.3 测试结论 5 推荐参考资料6… 文章目录 1 摘要2 核心 Maven 依赖3 核心代码3.1 服务端事务处理器 (DemoNettyServerHandler)3.2 服务端连接类(InitNettyServer)3.3 客户端事务处理器(DemoNettyClientHandler)3.4 客户端连接类(DemoNettyClient) 4 测试4.1 测试流程4.2 测试结果4.3 测试结论 5 推荐参考资料6 Github 源码 1 摘要
Netty 作为一款 NIO 底层通讯框架在高并发场景有着广泛的应用众多消息中间件内部也是基于 Netty 进行开发。本文将介绍基于 SpringBoot 2.7 集成 Netty 来模拟服务端与客户端进行通讯。
2 核心 Maven 依赖
demo-netty-server/pom.xml!-- Netty --dependencygroupIdio.netty/groupIdartifactIdnetty-all/artifactIdversion${netty.version}/version/dependencynetty 版本:
netty.version4.1.96.Final/netty.version3 核心代码
3.1 服务端事务处理器 (DemoNettyServerHandler)
demo-netty-server/src/main/java/com/ljq/demo/springboot/netty/server/handler/DemoNettyServerHandler.javapackage com.ljq.demo.springboot.netty.server.handler;import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;/*** Description: Netty 服务处理器* Author: junqiang.lu* Date: 2023/8/18*/
Slf4j
Component
// 标记该类实例可以被多个 channel 共享
ChannelHandler.Sharable
public class DemoNettyServerHandler extends ChannelInboundHandlerAdapter {/*** 每个传入的消息都会调用该方法** param ctx* param msg*/Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) {ByteBuf byteBuf (ByteBuf) msg;byte[] body new byte[byteBuf.readableBytes()];byteBuf.readBytes(body);log.info(服务端接收到数据:{}, new String(body));byte[] responseBytes hi,客户端,我是服务端.getBytes();ctx.writeAndFlush(Unpooled.wrappedBuffer(responseBytes));}/*** 在读取期间有异常抛出时会调用** param ctx* param cause*/Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {// 打印异常栈跟踪log.error(netty server error,cause);//关闭该channelctx.close();}}3.2 服务端连接类(InitNettyServer)
demo-netty-server/src/main/java/com/ljq/demo/springboot/netty/server/init/InitNettyServer.javapackage com.ljq.demo.springboot.netty.server.init;import com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler;
import io.netty.bootstrap.ServerBootstrap;
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.NioServerSocketChannel;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;import javax.annotation.Resource;
import java.net.InetSocketAddress;/*** Description: 初始化 netty 服务端* Author: junqiang.lu* Date: 2023/8/18*/
Slf4j
Component
public class InitNettyServer implements ApplicationRunner {Value(${netty.port:9120})private Integer nettyPort;Resourceprivate DemoNettyServerHandler nettyServerHandler;Overridepublic void run(ApplicationArguments args) throws Exception {this.start();}/*** 启动服务** throws InterruptedException*/public void start() throws InterruptedException {// 连接管理线程池EventLoopGroup mainGroup new NioEventLoopGroup(1);// 工作线程池EventLoopGroup workGroup new NioEventLoopGroup(4);ServerBootstrap bootstrap new ServerBootstrap();try {bootstrap.group(mainGroup, workGroup)// 指定 nio 通道.channel(NioServerSocketChannel.class)// 指定 socket 地址和端口.localAddress(new InetSocketAddress(nettyPort))// 添加子通道 handler.childHandler(new ChannelInitializerSocketChannel() {Overrideprotected void initChannel(SocketChannel socketChannel) throws Exception {socketChannel.pipeline().addLast(nettyServerHandler);}});// 异步绑定服务器调用sync方法阻塞等待直到绑定完成ChannelFuture channelFuture bootstrap.bind().sync();log.info(---------- [init] netty server start ----------);// 获取Channel的CloseFuture并且阻塞当前线程直到它完成channelFuture.channel().closeFuture().sync();} finally {// 关闭 EventLoopGroup释放资源mainGroup.shutdownGracefully().sync();}}}注意事项: 为什么要定义两个 EventLoopGroup ? 实际上这个 EventLoopGroup 相当于一个线程组如果只定义一个则这个线程组既负责服务端与客户端的连接管理也负责服务端的事务处理这就大大降低了服务端的吞吐量定义两个 EventLoopGroup 可以极大地提高系统的并发性能。
3.3 客户端事务处理器(DemoNettyClientHandler)
demo-netty-server/src/main/java/com/ljq/demo/springboot/netty/server/handler/DemoNettyClientHandler.javapackage com.ljq.demo.springboot.netty.server.handler;import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.ReferenceCountUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;/*** Description: netty 客户端处理器* Author: junqiang.lu* Date: 2023/8/18*/
Slf4j
Component
// 标记该类实例可以被多个 channel 共享
ChannelHandler.Sharable
public class DemoNettyClientHandler extends ChannelInboundHandlerAdapter {/*** 接收消息** param ctx* param msg* throws Exception*/Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {ByteBuf byteBuf (ByteBuf)msg;byte[] bodynew byte[byteBuf.readableBytes()];byteBuf.readBytes(body);log.info(接收到来自服务端的消息:{},new String(body));// 释放消息ReferenceCountUtil.release(msg);}/*** 和服务器建立连接时触发** param ctx* throws Exception*/Overridepublic void channelActive(ChannelHandlerContext ctx) throws Exception {log.info(客户端连接到服务器!!!);// 向服务端发送上线消息byte[] bytes hi,服务端我是客户端.getBytes();ByteBuf byteBuf Unpooled.wrappedBuffer(bytes);ctx.writeAndFlush(byteBuf);}/*** 有异常时触发** param ctx* param cause* throws Exception*/Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {log.error(客户端异常, cause);super.exceptionCaught(ctx, cause);}
}3.4 客户端连接类(DemoNettyClient)
demo-netty-server/src/main/java/com/ljq/demo/springboot/netty/server/client/DemoNettyClient.javapackage com.ljq.demo.springboot.netty.server.client;import com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.bytes.ByteArrayEncoder;
import io.netty.handler.codec.string.StringEncoder;
import lombok.extern.slf4j.Slf4j;import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;/*** Description: Netty 客户端* Author: junqiang.lu* Date: 2023/8/22*/
Slf4j
public class DemoNettyClient {private final String host;private final int port;private final EventLoopGroup mainGroup;private final Bootstrap bootstrap;private Channel channel;public DemoNettyClient(String host, int port) {this.host host;this.port port;this.mainGroup new NioEventLoopGroup();this.bootstrap new Bootstrap();}public Channel getChannel() {return this.channel;}/*** 创建连接*/public void connect() throws InterruptedException {bootstrap.group(mainGroup).channel(NioSocketChannel.class).remoteAddress(new InetSocketAddress(host, port)).handler(new ChannelInitializerSocketChannel() {Overrideprotected void initChannel(SocketChannel socketChannel) throws Exception {socketChannel.pipeline().addLast(new StringEncoder()).addLast(new ByteArrayEncoder()).addLast(new DemoNettyClientHandler());}});ChannelFuture future bootstrap.connect().sync();this.channel future.channel();}/*** 发送消息** param message*/public void sendMessage(String message) {log.info(客户端待发送消息:{}, message);Channel channel this.getChannel();byte[] bytes message.getBytes(StandardCharsets.UTF_8);ByteBuf byteBuf Unpooled.wrappedBuffer(bytes);channel.writeAndFlush(byteBuf);}public void close() throws InterruptedException {log.info(关闭客户端);mainGroup.shutdownGracefully().sync();}public static void main(String[] args) throws InterruptedException {String serverHost 127.0.0.1;int serverPort 9120;String message ahahaha啊哈哈哈啊哈;DemoNettyClient nettyClient new DemoNettyClient(serverHost, serverPort);nettyClient.connect();for (int i 0; i 10; i) {nettyClient.sendMessage(message i);}log.info(--------开始休眠 5 秒------------);Thread.sleep(5000L);for (int i 0; i 5; i) {nettyClient.sendMessage(i message);Thread.sleep(100L);}nettyClient.close();}}4 测试
4.1 测试流程
先启动 SpringBoot 应用程序此时服务端已经启动完成
再执行客户端连接类(DemoNettyClient) 中的 main 方法
4.2 测试结果
客户端日志:
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈0
2023-08-23 11:27:11 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 48| 客户端连接到服务器!!!
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈1
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈2
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈3
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈4
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈5
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈6
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈7
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈8
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:ahahaha啊哈哈哈啊哈9
2023-08-23 11:27:11 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 96| --------开始休眠 5 秒------------
2023-08-23 11:27:11 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:16 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:0ahahaha啊哈哈哈啊哈
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:16 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:1ahahaha啊哈哈哈啊哈
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:16 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:2ahahaha啊哈哈哈啊哈
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:17 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:3ahahaha啊哈哈哈啊哈
2023-08-23 11:27:17 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:17 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 74| 客户端待发送消息:4ahahaha啊哈哈哈啊哈
2023-08-23 11:27:17 | INFO | nioEventLoopGroup-2-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyClientHandler 35| 接收到来自服务端的消息:hi,客户端,我是服务端
2023-08-23 11:27:17 | INFO | main | com.ljq.demo.springboot.netty.server.client.DemoNettyClient 82| 关闭客户端
Disconnected from the target VM, address: 127.0.0.1:56274, transport: socket服务端日志:
2023-08-23 11:27:11 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:hi,服务端我是客户端ahahaha啊哈哈哈啊哈0ahahaha啊哈哈哈啊哈1ahahaha啊哈哈哈啊哈2ahahaha啊哈哈哈啊哈3ahahaha啊哈哈哈啊哈4ahahaha啊哈哈哈啊哈5ahahaha啊哈哈哈啊哈6ahahaha啊哈哈哈啊哈7ahahaha啊哈哈哈啊哈8ahahaha啊哈哈哈啊哈9
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:0ahahaha啊哈哈哈啊哈
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:1ahahaha啊哈哈哈啊哈
2023-08-23 11:27:16 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:2ahahaha啊哈哈哈啊哈
2023-08-23 11:27:17 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:3ahahaha啊哈哈哈啊哈
2023-08-23 11:27:17 | INFO | nioEventLoopGroup-3-1 | com.ljq.demo.springboot.netty.server.handler.DemoNettyServerHandler 33| 服务端接收到数据:4ahahaha啊哈哈哈啊哈4.3 测试结论
1从日志中可以看出客户端与服务端已经通讯成功2在第一个客户端循环发送消息中客户端发了10次然而服务端一次性接收到了所有消息并不是发送一次接收一次3在第二个客户端循环发送消息过程中客户端每间隔100毫秒发送一条消息此时服务端是一条一条接收的
关于第2点这是 Netty 通讯过程中的粘包问题欲知如何解决且听下回分解。
关于第3点由于添加了时间间隔Netty 会认为一条消息发送完成因此就能发送一条接收一条。
5 推荐参考资料
[Netty入门] 最简单的Netty应用程序实例
Netty4一个简单的消息传递的demo(分析和解析)
6 Github 源码
Gtihub 源码地址 : https://github.com/Flying9001/springBootDemo/tree/master/demo-netty-server
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