这篇文章主要介绍“Netty框架实现TCP/IP通信的详细过程”，在日常操作中，相信很多人在Netty框架实现TCP/IP通信的详细过程问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”Netty框架实现TCP/IP通信的详细过程”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
项目中需要使用到TCP/IP协议完成数据的发送与接收。如果只是用以前写的简单的socket套接字方法，每次接收发送消息都会创建新的socket再关闭socket，造成资源浪费。于是使用netty框架完成java网络通信。
Netty框架的内容很多，这里只是代码展示其中的一个功能。
代码仓库
这里使用的是Springboot+Netty框架，使用maven搭建项目。这里是在一个项目中搭建服务端与客户端，所以端口一样。还可以使用TCP/UTP工具自己搭建服务端和客户端，只要在yml文件中修改ip和端口就好。
pom.xml
<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.hzx.testmaven15netty</groupId> <artifactId>testmaven15netty</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.3.0.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.31.Final</version> </dependency> </dependencies></project>application.yml
server: port: 8080# 作为客户端请求的服务端地址netty: tcp: server: # 作为客户端请求的服务端地址 host: 127.0.0.1 # 作为客户端请求的服务端端口 port: 7000 client: # 作为服务端开放给客户端的端口 port: 7000服务端
import io.netty.bootstrap.ServerBootstrap;import io.netty.channel.Channel;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelOption;import io.netty.channel.EventLoopGroup;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioServerSocketChannel;import io.netty.util.concurrent.Future;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;@Componentpublic class NettyTcpServer { private static final Logger LOGGER = LoggerFactory.getLogger(NettyTcpServer.class); // boss事件轮询线程组 // 处理Accept连接事件的线程，这里线程数设置为1即可，netty处理链接事件默认为单线程，过度设置反而浪费cpu资源 private EventLoopGroup boss = new NioEventLoopGroup(1); //worker事件轮询线程组 //处理handler的工作线程，其实也就是处理IO读写 。线程数据默认为 CPU 核心数乘以2 private EventLoopGroup worker = new NioEventLoopGroup(); @Autowired ServerChannelInitializer serverChannelInitializer; @Value("${netty.tcp.client.port}") private Integer port; // 与客户端建立连接后得到的通道对象 private Channel channel; public static Map<String, Channel> map = new ConcurrentHashMap<String, Channel>(); public ChannelFuture start() { // 启动类 ServerBootstrap serverBootstrap = new ServerBootstrap(); serverBootstrap.group(boss, worker)//组配置，初始化ServerBootstrap的线程组 .channel(NioServerSocketChannel.class)//构造channel通道工厂 bossGroup的通道，只是负责连接 .childHandler(serverChannelInitializer) //设置通道处理者ChannelHandlerWorkerGroup的处理器 .option(ChannelOption.SO_BACKLOG, 1024)//socket参数，当服务器请求处理程全满时，用于临时存放已完成三次握手请求的队列的最大长度。如果未设置或所设置的值小于1，Java将使用默认值50。 .childOption(ChannelOption.SO_KEEPALIVE, true);//启用心跳保活机制，tcp，默认2小时发一次心跳 //Future：异步任务的生命周期，可用来获取任务结果 ChannelFuture channelFuture1 = serverBootstrap.bind(port).syncUninterruptibly(); // 绑定端口 开启监听 同步等待 if (channelFuture1 != null && channelFuture1.isSuccess()) { channel = channelFuture1.channel();// 获取通道 LOGGER.info("Netty tcp server start success,port={}",port); }else { LOGGER.error("Netty tcp server start fail"); } return channelFuture1; } public void destroy(){ if (channel != null) { channel.close(); } try { Future<?> future = worker.shutdownGracefully().await(); if (!future.isSuccess()) { LOGGER.error("netty tcp workerGroup shutdown fail,{}",future.cause()); } } catch (InterruptedException e) { LOGGER.error(e.toString()); } LOGGER.info("Netty tcp server shutdown success"); }}import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.socket.SocketChannel;import io.netty.handler.codec.string.StringDecoder;import io.netty.handler.codec.string.StringEncoder;import io.netty.handler.timeout.IdleStateHandler;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import java.util.concurrent.TimeUnit;@Componentpublic class ServerChannelInitializer extends ChannelInitializer<SocketChannel> { @Autowired ServerChannelHandler serverChannelHandler; @Override protected void initChannel(SocketChannel socketChannel) throws Exception { ChannelPipeline pipeline = socketChannel.pipeline(); //IdleStateHandler心跳机制,如果超时触发Handle中userEventTrigger()方法 pipeline.addLast("idleStateHandler", new IdleStateHandler(15,0,0, TimeUnit.MINUTES)); // 字符串编解码器 pipeline.addLast( new StringDecoder(), new StringEncoder() ); // 自定义Handler pipeline.addLast("serverChannelHandler",serverChannelHandler); }}import io.netty.channel.ChannelHandler;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import io.netty.handler.timeout.IdleState;import io.netty.handler.timeout.IdleStateEvent;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.stereotype.Component;@Component@ChannelHandler.Sharablepublic class ServerChannelHandler extends SimpleChannelInboundHandler<Object> { private static final Logger LOGGER = LoggerFactory.getLogger(ServerChannelHandler.class); @Override protected void channelRead0(ChannelHandlerContext channelHandlerContext, Object msg) throws Exception { LOGGER.info("Netty tcp server receive message: {}",msg); channelHandlerContext.writeAndFlush(" response message "+msg).syncUninterruptibly(); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { super.channelActive(ctx); LOGGER.info("tcp client "+getRemoteAddress(ctx)+" connect success"); NettyTcpServer.map.put(getIPString(ctx),ctx.channel()); } @Override public void channelInactive(ChannelHandlerContext ctx) throws Exception { // 删除Channel Map中失效的Client NettyTcpServer.map.remove(getIPString(ctx)); ctx.close(); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { super.exceptionCaught(ctx, cause); // 发生异常 关闭连接 LOGGER.error("引擎{}的通道发生异常，断开连接",getRemoteAddress(ctx)); ctx.close(); } @Override public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception { String socketString = ctx.channel().remoteAddress().toString(); if (evt instanceof IdleStateEvent) { IdleStateEvent event = (IdleStateEvent) evt; if (event.state()== IdleState.READER_IDLE) { LOGGER.info("Client: "+socketString+" READER_IDLE读超时"); ctx.disconnect(); }else if (event.state()==IdleState.WRITER_IDLE){ LOGGER.info("Client: "+socketString+" WRITER_IDLE写超时"); ctx.disconnect(); }else if (event.state()==IdleState.ALL_IDLE){ LOGGER.info("Client: "+socketString+" ALL_IDLE总超时"); ctx.disconnect(); } } } public String getRemoteAddress(ChannelHandlerContext channelHandlerContext){ String socketString = ""; socketString = channelHandlerContext.channel().remoteAddress().toString(); return socketString; } public String getIPString(ChannelHandlerContext channelHandlerContext){ String ipString = ""; String socketString = channelHandlerContext.channel().remoteAddress().toString(); int colonAt = socketString.indexOf(":"); ipString = socketString.substring(1,colonAt); return ipString; }}客户端
import io.netty.bootstrap.Bootstrap;import io.netty.channel.Channel;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelOption;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioSocketChannel;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import javax.xml.ws.Holder;@Componentpublic class NettyTcpClient { private static final Logger LOGGER = LoggerFactory.getLogger(NettyTcpClient.class); @Value("${netty.tcp.server.host}") String HOST; @Value("${netty.tcp.server.port}") int PORT; @Autowired ClientChannelInitializer clientChannelInitializer; private Channel channel; private final Bootstrap getBootstrap(){ Bootstrap bootstrap = new Bootstrap(); NioEventLoopGroup group = new NioEventLoopGroup(); bootstrap.group(group) .channel(NioSocketChannel.class)//通道连接者 .handler(clientChannelInitializer)//通道处理者 .option(ChannelOption.SO_KEEPALIVE,true);// 心跳报活 return bootstrap; } public void connect(){ ChannelFuture channelFuture = getBootstrap().connect(HOST, PORT).syncUninterruptibly(); if (channelFuture != null&&channelFuture.isSuccess()) { channel = channelFuture.channel(); LOGGER.info("connect tcp server host = {},port = {} success", HOST,PORT); }else { LOGGER.error("connect tcp server host = {},port = {} fail",HOST,PORT); } } public void sendMessage(Object msg) throws InterruptedException { if (channel != null) { channel.writeAndFlush(msg).sync(); }else { LOGGER.warn("消息发送失败，连接尚未建立"); } }}import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.socket.SocketChannel;import io.netty.handler.codec.string.StringDecoder;import io.netty.handler.codec.string.StringEncoder;import io.netty.handler.timeout.IdleStateHandler;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import java.util.concurrent.TimeUnit;@Componentpublic class ClientChannelInitializer extends ChannelInitializer<SocketChannel> { @Autowired ClientChannelHandler clientChannelHandler; @Override protected void initChannel(SocketChannel socketChannel) throws Exception { ChannelPipeline pipeline = socketChannel.pipeline(); pipeline.addLast("idleStateHandler", new IdleStateHandler(15,0,0, TimeUnit.MINUTES)); pipeline.addLast(new StringDecoder(),new StringEncoder()); pipeline.addLast("clientChannelHandler",clientChannelHandler); }}import io.netty.channel.ChannelHandler;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.stereotype.Component;@Component@ChannelHandler.Sharablepublic class ClientChannelHandler extends SimpleChannelInboundHandler<Object> { private static final Logger LOGGER = LoggerFactory.getLogger(ClientChannelHandler.class); @Override protected void channelRead0(ChannelHandlerContext channelHandlerContext, Object msg) throws Exception { LOGGER.info("Netty tcp client receive msg : " + msg); }}启动类
import com.netty.client.NettyTcpClient;import com.netty.server.NettyTcpServer;import io.netty.channel.ChannelFuture;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.CommandLineRunner;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublic class StartApplication implements CommandLineRunner { public static void main(String[] args) throws Exception { SpringApplication.run(StartApplication.class, args); } @Autowired NettyTcpServer nettyTcpServer; @Autowired NettyTcpClient nettyTcpClient; @Override public void run(String... args) throws Exception { ChannelFuture start = nettyTcpServer.start(); nettyTcpClient.connect(); for (int i = 0; i < 10; i++) { nettyTcpClient.sendMessage("hello world "+i); } start.channel().closeFuture().syncUninterruptibly(); }}使用循环让客户端向服务端发送10条数据
运行结果
"C:\Program Files\Java\jdk1.8.0_271\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\IDEA\IntelliJ IDEA 2019.1.1\lib\idea_rt.jar=62789:D:\IDEA\IntelliJ IDEA 2019.1.1\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_271\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sqljdbc4-4.0.0.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_271\jre\lib\rt.jar;D:\Java Code\testmaven15netty\target\classes;D:\Maven\myreprository\org\springframework\boot\spring-boot-starter\2.3.0.RELEASE\spring-boot-starter-2.3.0.RELEASE.jar;D:\Maven\myreprository\org\springframework\boot\spring-boot\2.3.0.RELEASE\spring-boot-2.3.0.RELEASE.jar;D:\Maven\myreprository\org\springframework\spring-context\5.2.6.RELEASE\spring-context-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\springframework\spring-aop\5.2.6.RELEASE\spring-aop-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\springframework\spring-beans\5.2.6.RELEASE\spring-beans-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\springframework\spring-expression\5.2.6.RELEASE\spring-expression-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\springframework\boot\spring-boot-autoconfigure\2.3.0.RELEASE\spring-boot-autoconfigure-2.3.0.RELEASE.jar;D:\Maven\myreprository\org\springframework\boot\spring-boot-starter-logging\2.3.0.RELEASE\spring-boot-starter-logging-2.3.0.RELEASE.jar;D:\Maven\myreprository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\Maven\myreprository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\Maven\myreprository\org\slf4j\slf4j-api\1.7.30\slf4j-api-1.7.30.jar;D:\Maven\myreprository\org\apache\logging\log4j\log4j-to-slf4j\2.13.2\log4j-to-slf4j-2.13.2.jar;D:\Maven\myreprository\org\apache\logging\log4j\log4j-api\2.13.2\log4j-api-2.13.2.jar;D:\Maven\myreprository\org\slf4j\jul-to-slf4j\1.7.30\jul-to-slf4j-1.7.30.jar;D:\Maven\myreprository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;D:\Maven\myreprository\org\springframework\spring-core\5.2.6.RELEASE\spring-core-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\springframework\spring-jcl\5.2.6.RELEASE\spring-jcl-5.2.6.RELEASE.jar;D:\Maven\myreprository\org\yaml\snakeyaml\1.26\snakeyaml-1.26.jar;D:\Maven\myreprository\io\netty\netty-all\4.1.31.Final\netty-all-4.1.31.Final.jar" com.netty.StartApplication
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/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
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=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.3.0.RELEASE)2021-07-13 08:32:17.161 INFO 18068 --- [ main] com.netty.StartApplication : Starting StartApplication on LAPTOP-H9JFQJGF with PID 18068 (D:\Java Code\testmaven15netty\target\classes started by huangzixiao in D:\Java Code\testmaven15netty)
2021-07-13 08:32:17.165 INFO 18068 --- [ main] com.netty.StartApplication : No active profile set, falling back to default profiles: default
2021-07-13 08:32:18.371 INFO 18068 --- [ main] com.netty.StartApplication : Started StartApplication in 1.706 seconds (JVM running for 2.672)
2021-07-13 08:32:18.931 INFO 18068 --- [ main] com.netty.server.NettyTcpServer : Netty tcp server start success,port=7000
2021-07-13 08:32:19.016 INFO 18068 --- [ main] com.netty.client.NettyTcpClient : connect tcp server host = 127.0.0.1,port = 7000 success
2021-07-13 08:32:19.078 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : tcp client /127.0.0.1:52653 connect success
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 0
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 1
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 0
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 2
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 1
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 3
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 2
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 4
2021-07-13 08:32:19.100 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 3
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 5
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 4
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 6
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 5
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 7
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 6 response message hello world 7
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 8
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 8
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-3-1] com.netty.server.ServerChannelHandler : Netty tcp server receive message: hello world 9
2021-07-13 08:32:19.104 INFO 18068 --- [ntLoopGroup-4-1] com.netty.client.ClientChannelHandler : Netty tcp client receive msg : response message hello world 9
到此，关于“Netty框架实现TCP/IP通信的详细过程”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注编程网网站，小编会继续努力为大家带来更多实用的文章！
