物联网消息队列客户端-MQTT-基本功能实现

1. 主要实现功能

自动配置
消息自动解析
消息分组共享订阅
消息不分组共享订阅
消息排它订阅
延时发布
多数据源

4. 快速开始

4.1 引入依赖

    
            org.eclipse.paho
            org.eclipse.paho.client.mqttv3
            1.2.5

4.2 配置

spring:
  mqtt:
    emq:
      client:
        # 多数据源客户端名称，默认default
        default:
          # broker地址
          host: 127.0.0.1
          # 端口
          port: 31883
          # 用户名
          username: admin
          # 密码
          password: 123456

更多配置如下

spring:
  mqtt:
    emq:
      client:
        # 多数据源客户端名称，默认default
        default:
          # broker地址
          host: 127.0.0.1
          # 端口
          port: 31883
          # 用户名
          username: admin
          # 密码
          password: 123456
          # 客户端标识，需保持全局唯一
          client-id: parking_server
          # 是否清除session
          clean-session: false
          # 连接超时时间，单位秒
          connection-timeout: 10
          # 心跳间隔时间，单位秒
          keep-alive-interval: 10
          # 全局消息质量
          global-qos: 1
          # 重新连接之间等待的最长时间
          maxReconnect-delay: 128000
          # 是否自动重新连接
          automatic-reconnect: true
          # 最大消息并发数量，超过此数量并发时可能会丢消息
          maxInflight: 1000

4.3 开启自动配置

在启动类上增加@EnableRabbitMqAutoConfiguration注解

import com.demo.mqttclient.anno.EnableEmqAutoConfiguration;


@SpringBootApplication
@EnableEmqAutoConfiguration
public class TestApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestApplication.class, args);
    }

}

4.4 发布消息

在生产者的业务程序中，注入MQTTClient

import com.demo.mqttclient.MQTTClient;

@Resource
private MQTTClient defaultMQTTClient;

为了兼容第三方及优化内部使用逻辑，所以内置提供了两种消息发送方式。

4.4.1 第三方消息发送

public String publishHeartbeatReply() {
    HeartbeatReplyMessage heartbeatReplyMessage = new HeartbeatReplyMessage();
    heartbeatReplyMessage.setCmd(32896);
    heartbeatReplyMessage.setExpire(1605252875L);
    heartbeatReplyMessage.setDevid("095437323930030130523933");
    heartbeatReplyMessage.setServer_time("1605252875");

    defaultMQTTClient.publish2ThirdParty("npt/park/type1/dev/095437323930030130523933", 1, heartbeatReplyMessage);

    return "success";
}

4.4.2 内部消息发送

消息实体实现Message接口

package com.example.test.message;

import com.demo.mqttclient.MQTTMessage;
import lombok.Data;

import java.util.UUID;

@Data
public class demoMessage implements MQTTMessage {
    
    private String msgId = UUID.randomUUID().toString();
    
    private String name;
    
    private String gender;
    
    @Override
    public String getMsgId() {
        return this.msgId;
    }
    
}

然后直接调用该类的publish方法发送即可

@GetMapping("demo/publish")
public String demoPublish() {
    demoMessage demoMessage = new demoMessage();
    demoMessage.setName("点都");
    demoMessage.setGender("xx");

    defaultMQTTClient.publish("demo/topic", demoMessage);

    return "success";
}

其中存在多个重载的方法。

package com.demo.mqttclient;

import com.demo.mqttclient.enums.ShareModelEnum;
import com.demo.plugin.core.lang.json.JSONUtil;
import org.eclipse.paho.client.mqttv3.MqttMessage;


public interface MQTTClient {

    
    void start();

    
    void close();

    
    default  void publish(String topic, T message) {
        this.publish(topic, message, 1);
    }

    
    default  void publish(String topic, T message, int qos) {
        this.publish(topic, message, qos, 0);
    }

    
    default  void publish(String topic, T message, int qos, long delay) {
        this.publish(topic, message, qos, delay, false);
    }

    
    default  void publish(String topic, T message, int qos, long delay, boolean retained) {
        MQTTMessageContext mqttMessageContext = new MQTTMessageContext();
        mqttMessageContext.setId(message.getMsgId());
        mqttMessageContext.setPayload(JSONUtil.write(message));
        mqttMessageContext.setQos(qos);
        mqttMessageContext.setDelay(delay);
        mqttMessageContext.setRetained(retained);
        mqttMessageContext.setTimestamp(System.currentTimeMillis());

        this.publish(topic, mqttMessageContext);
    }

    
    void publish(String topic, MQTTMessageContext messageContext);

    
    default void publish2ThirdParty(String topic, Object message) {
        this.publish2ThirdParty(topic, 1, message);
    }

    
    default void publish2ThirdParty(String topic, int qos, Object message) {
        this.publish2ThirdParty(topic, qos, message, Constant.DEFAULT_CHARSET.name());
    }

    
    default void publish2ThirdParty(String topic, int qos, Object message, String charsetName) {
        this.publish2ThirdParty(topic, qos, message, charsetName, 0);
    }

    
    default void publish2ThirdParty(String topic, int qos, Object message, String charsetName, long delay) {
        this.publish2ThirdParty(topic, qos, message, charsetName, delay, false);
    }

    
    default void publish2ThirdParty(String topic, int qos, Object message, String charsetName, long delay, boolean retained) {
        this.publish2ThirdParty(topic, qos, JSONUtil.toString(message).getBytes(charsetName), delay, retained);
    }

    
    default void publish2ThirdParty(String topic, byte[] payload) {
        this.publish2ThirdParty(topic, 1, payload, 0);
    }

    
    default void publish2ThirdParty(String topic, int qos, byte[] payload) {
        this.publish2ThirdParty(topic, qos, payload, 0);
    }

    
    default void publish2ThirdParty(String topic, int qos, byte[] payload, long delay) {
        this.publish2ThirdParty(topic, qos, payload, delay, false);
    }

    
    default void publish2ThirdParty(String topic, int qos, byte[] payload, long delay, boolean retained) {
        MqttMessage mqttMessage = new MqttMessage();
        mqttMessage.setPayload(payload);
        mqttMessage.setQos(qos);
        mqttMessage.setRetained(retained);

        this.publish2ThirdParty(topic, delay, mqttMessage);
    }

    
    void publish2ThirdParty(String topic, long delay, MqttMessage mqttMessage);

    
    void subscribe(String topic, int qos, ShareModelEnum shareModel, String groupName, boolean exclusive, MessageHandler messageHandler);

}

4.5 接收消息

消费者需要在消息处理类上添加@MQTTSubscriber(topics = {"npt/park/type1/server/10010"})注解，指定要监听topics和客户端名称即可。如果没有显示的指定客户端名称，则使用defaultMQTTClient，使用qos执行订阅消息质量。
当消息处理类中有多个public方法时，需要@MQTTConsumerMethod标记具体消费方法

package com.example.test.handler;

import com.demo.mqttclient.MessageHandler;
import com.demo.mqttclient.anno.MQTTConsumerMethod;
import com.demo.mqttclient.anno.MQTTSubscriber;
import com.demo.mqttclient.enums.ShareModelEnum;
import com.demo.plugin.core.lang.json.JSONUtil;
import com.example.test.message.DeviceStartMessage;
import com.example.test.message.PlateRecognitionReportMessage;
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.MqttMessage;

import java.util.Map;


@Slf4j
@MQTTSubscriber(topics = ParkingMessageHandler.TOPIC, qos = 1, share = ShareModelEnum.GROUP_SHARE)
public class ParkingMessageHandler {

    public static final String TOPIC = "npt/park/type1/server/10010";

    public static final String CMD_KEY = "cmd";

    @MQTTConsumerMethod
    public void handle(Map message) {
        log.info("handle:{}", message);
        if (message.containsKey(CMD_KEY)) {
            Integer cmd = (Integer) message.get(CMD_KEY);

            switch (cmd) {
                case 129:
                    handleDeviceStartMessage(message);
                    break;
                case 140:
                    handlePlateRecognitionReportMessage(message);
                    break;
                default:
                    log.warn("不支持此cmd:[{}]", cmd);
                    break;
            }
        } else {
            log.warn("消息消费异常");
        }
    }

    private void handleDeviceStartMessage(Map message) {
        DeviceStartMessage deviceStartMessage = JSONUtil.toObject(JSONUtil.toString(message), DeviceStartMessage.class);
        log.info("接收到设备启动消息:{}", deviceStartMessage);
    }

    private void handlePlateRecognitionReportMessage(Map message) {
        PlateRecognitionReportMessage plateRecognitionReportMessage = JSONUtil.toObject(JSONUtil.toString(message), PlateRecognitionReportMessage.class);
        log.info("接收到车牌上报识别消息:{}", plateRecognitionReportMessage);
    }

}

4.6 发送延迟消息

要发送延迟消息，需要先开启emq延迟发布配置。
发送延时消息的方式相比之前，仅仅增加一个延时时间。其中延时时长的单位为秒，最大为4294967秒

//发送一个延时时长为10s的消息
defaultMQTTClient.publish2ThirdParty("npt/park/type1/dev/095437323930030130523933", 1, heartbeatReplyMessage, 10);

4.7 多数据源

多数据源与单数据源配置属性相同，在配置文件中声明即可

spring:
  mqtt:
    emq:
      client:
        # 多数据源客户端名称，默认default
        default:
          # broker地址
          host: 127.0.0.1
          # 端口
          port: 31883
          # 用户名
          username: admin
          # 密码
          password: 123456
        # 多数据源客户端名称
        parking:
          # broker地址
          host: 127.0.0.1
          # 端口
          port: 31883
          # 用户名
          username: admin
          # 密码
          password: 123456

4.7.1 发布消息

首先注入MQTTClient，与单数据源的唯一区别就是bean的名称。默认向Spring容器中添加的实现类名称为“${数据源名称}MQTTClient”
以上面的配置文件为例，默认的bean名称为 defaultMQTTClient 和 billMQTTClient

import com.demo.mqttclient.MQTTClient;

@Resource
private MQTTClient defaultMQTTClient;

@Resource
private MQTTClient billMQTTClient;

其他操作同单数据源

4.7.2 接收消息

接收消息与单数据源基本一致，唯一的区别是在@MQTTSubscriber中指定clientName属性，指定当前从哪个数据源进行消费。

import com.demo.mqttclient.anno.MQTTSubscriber;

@MQTTSubscriber(topics = {"npt/park/type1/server/10010"}, clientName = "parking")
public class ParkingMessageHandler {}

4.8 分组共享订阅

系统默认使用spring.application.name作为分组名称，用户可在消息消费类上指定@MQTTSubscriber属性中groupName = "group_name"即可

import com.demo.mqttclient.anno.MQTTSubscriber;

@MQTTSubscriber(topics = ParkingMessageHandler.TOPIC, qos = 1, share = ShareModelEnum.GROUP_SHARE, groupName = "group_name")
public class ParkingMessageHandler {}

4.9 不分组共享订阅

只需要在消息消费类上指定@MQTTSubscriber属性中share = ShareModelEnum.UN_GROUP_SHARE即可。

import com.demo.mqttclient.anno.MQTTSubscriber;

@MQTTSubscriber(topics = ParkingMessageHandler.TOPIC, qos = 1, share = ShareModelEnum.UN_GROUP_SHARE)
public class ParkingMessageHandler {}

4.10 排它订阅

只需要在消息消费类上指定@MQTTSubscriber属性中exclusive = true即可，开启排它订阅时，默认关闭共享订阅。

import com.demo.mqttclient.anno.MQTTSubscriber;

@MQTTSubscriber(topics = ParkingMessageHandler.TOPIC, qos = 1, exclusive = true)
public class ParkingMessageHandler {}

物联网消息队列客户端-MQTT-基本功能实现

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