物联网 基于netty核心实战-握手与认证

• 物联网 基于netty核心实战-握手与认证
  • 简述
  • 源码(netty-sample-05-auth)
  • 协议结构
  • 简易demo
    • 服务端
    • 客户端

物联网 基于netty核心实战-握手与认证

简述

MQTT PUBLISH 报文 的二进制结构（固定头、可变头、有效载荷），并基于 Netty 实现一个支持 QoS 0 的发布/订阅 Broker

源码(netty-sample-05-auth)

https://gitee.com/kcnf-iot/iot-sample/tree/master/netty/netty-sample-05

协议结构

MQTT 报文结构	Netty 中的对应 Java 类	关键字段/作用
固定报头 (Fixed Header)	MqttFixedHeader	包含 messageType (如 CONNECT), qosLevel, isRetain 等标志位
可变报头 (Variable Header)	MqttConnectVariableHeader	包含协议名、版本号、连接标志（如 Clean Session）、保活时间
有效载荷 (Payload)	MqttConnectPayload	包含实际数据，如客户端ID、遗嘱消息、用户名和密码
完整连接请求	MqttConnectMessage	一个对象就包含了上述三部分，可以直接在处理器中使用

简易demo

服务端

package com.jysemel.iot;

import com.jysemel.iot.handler.MqttAuthHandler;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.mqtt.MqttDecoder;
import io.netty.handler.codec.mqtt.MqttEncoder;

public class MqttAuthServer {
    public static void main(String[] args) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) {
                            ChannelPipeline p = ch.pipeline();
                            // (A) 使用 Netty 内置的 MqttDecoder
                            p.addLast("mqttDecoder", new MqttDecoder(1024));
                            // (B) 使用单例的 MqttEncoder
                            p.addLast("mqttEncoder", MqttEncoder.INSTANCE);
                            // (C) 实现我们自己的业务逻辑处理器
                            p.addLast("authHandler", new MqttAuthHandler());
                        }
                    });
            ChannelFuture f = b.bind(1883).sync();
            System.out.println("MQTT Auth Server started on port 1883");
            f.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

客户端

package com.jysemel.iot;

import com.jysemel.iot.handler.MqttAuthClientHandler;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.mqtt.MqttDecoder;
import io.netty.handler.codec.mqtt.MqttEncoder;

public class MqttAuthClient {
    public static void main(String[] args) throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) {
                            ChannelPipeline p = ch.pipeline();
                            p.addLast("mqttDecoder", new MqttDecoder(1024));
                            p.addLast("mqttEncoder", MqttEncoder.INSTANCE);
                            p.addLast("clientHandler", new MqttAuthClientHandler());
                        }
                    });
            ChannelFuture f = b.connect("127.0.0.1", 1883).sync();
            f.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }
}