简述

最近在一些场景中需要使用UDP客户端进行，所以开始集成新的东西。本文集成了一个基于netty的SpringBoot的简单的应用场景。

Netty-UDP集成

pom引入

        <!-- netty --><dependency><groupId>io.netty</groupId><artifactId>netty-all</artifactId><version>4.1.84.Final</version></dependency>

如果项目本身使用redis,则redis默认会集成,我的项目中默认有netty-4.1.84.Final

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency>

Client

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioDatagramChannel;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;/*** @author fir*/
@Slf4j
@Component
public class LogPushUdpClient implements ApplicationRunner {private final Bootstrap bootstrap;public final NioEventLoopGroup workerGroup;public static Channel channel;@Overridepublic void run(ApplicationArguments args) {start();}public void start() {try {log.info("UDP客户端--启动");channel = bootstrap.bind(1234).sync().channel();channel.closeFuture().await(1000);} catch (InterruptedException e) {log.info("UDP客户端启动失败");}}private LogPushUdpClient() {bootstrap = new Bootstrap();workerGroup = new NioEventLoopGroup();bootstrap.group(workerGroup).channel(NioDatagramChannel.class).option(ChannelOption.SO_BROADCAST, true).handler(new ChannelInitializer<NioDatagramChannel>() {@Overrideprotected void initChannel(NioDatagramChannel ch) {// 获取了通道的管道，管道是一个处理网络事件和操作的处理器链。ChannelPipeline pipeline = ch.pipeline();// 向管道添加了自定义的 LogPushUdpClientHandler 处理器，它将处理网络 I/O 事件和数据pipeline.addLast(new LogPushUdpClientHandler());}});}}

Handler

package com.fir.home.handler.udp;import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.socket.DatagramPacket;
import io.netty.util.concurrent.GenericFutureListener;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;import lombok.extern.slf4j.Slf4j;/*** @author fir*/
@Slf4j
public class LogPushUdpClientHandler extends SimpleChannelInboundHandler<DatagramPacket> {public static HashMap<Long, Boolean> treedMap = new HashMap<>();/*** 客户端初次连接时执行的方法** @param ctx 通道处理上下文*/@Overridepublic void channelActive(ChannelHandlerContext ctx) {log.info("客户端通道已就绪!");}@Overrideprotected void channelRead0(ChannelHandlerContext ctx, DatagramPacket packet) {final ByteBuf buf = packet.content();int readableBytes = buf.readableBytes();byte[] content = new byte[readableBytes];buf.readBytes(content);String serverMessage = new String(content);log.info("[UDP客户端]接受消息: " + serverMessage);}/*** 向服务器发送消息** @param msg               按规则拼接的消息串* @param inetSocketAddress 目标服务器地址*/public static void sendMessage(final String msg, final InetSocketAddress inetSocketAddress) {log.info("[UDP客户端]发送消息消息: " + msg);if (msg == null) {throw new NullPointerException("[UDP客户端]发送数据为空");}DatagramPacket datagramPacket = datagramPacket(msg, inetSocketAddress);senderInternal(datagramPacket);}/*** 组装数据包** @param msg               消息串* @param inetSocketAddress 服务器地址* @return DatagramPacket*/public static DatagramPacket datagramPacket(String msg, InetSocketAddress inetSocketAddress) {DatagramPacket datagramPacket;ByteBuf dataBuf = Unpooled.copiedBuffer(msg, StandardCharsets.UTF_8);datagramPacket = new DatagramPacket(dataBuf, inetSocketAddress);return datagramPacket;}/*** 发送数据包服务器无返回结果** @param datagramPacket 数据报文包*/private static void senderInternal(final DatagramPacket datagramPacket) {if (LogPushUdpClient.channel != null) {LogPushUdpClient.channel.writeAndFlush(datagramPacket).addListener((GenericFutureListener<ChannelFuture>) future -> {boolean success = future.isSuccess();if (log.isInfoEnabled()) {log.info("[UDP客户端]发送结果 : " + success);}});} else {throw new NullPointerException("UPD上下文通道为空");}}
}

调用

        InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1", 50000);LogPushUdpClientHandler.sendMessage("hello", inetSocketAddress);

消息发送与接收

在线UDP服务

服务端可以使用在线UDP服务
http://udp.xnkiot.com/

系统调用

调用后，可以看到，数据发送成功，并且接受成功。