Mqtt消费端实现的几种方式

此处测试的mqtt的Broker是使用的EMQX 5.7.1，可移步至https://blog.csdn.net/tiantang_1986/article/details/140443513查看详细介绍

一、方式1

添加必要的依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-integration</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-mqtt</artifactId>
</dependency>

配置

# mqtt 服务端配置
spring:
  # mqtt 配置
  mqtt:
    url: tcp://127.0.0.1:1883,tcp://127.0.0.2:1883
    clientId: "00000001"       # 客户端Id（不可重复）
    username: <访问用户名>      # 认证的用户名
    password: <访问密码>        # 认证的密码
    qos: 1
    topic: test/#              # 监听的topic

读取配置文件

import org.apache.commons.lang3.StringUtils;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;

@Data
@Configuration
@ConfigurationProperties(prefix = "spring.mqtt")
public class MqttConfig {
    private String username;
    private String password;
    private String url;
    private String clientId;
    private String topic;
    private Integer qos;

    @Bean
    public MqttPahoClientFactory mqttClientFactory() {
        DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
        MqttConnectOptions options = new MqttConnectOptions();
        options.setUserName(username);
        options.setPassword(password.toCharArray());
        if (StringUtils.isNotBlank(url) && url.contains(",")) {
            options.setServerURIs(url.split(","));
        } else {
            options.setServerURIs(new String[]{url});
        }        
        options.setCleanSession(true);
        //自动重连
        options.setAutomaticReconnect(true);
        //设置超时时间，单位为秒
        options.setConnectionTimeout(0);
        //设置心跳时间 单位为秒，表示服务器每隔 1.5*20秒的时间向客户端发送心跳判断客户端是否在线
        options.setKeepAliveInterval(90);
        //设置遗嘱消息
        options.setWill("will_topic", (this.clientId + "与服务器断开连接").getBytes(), qos, false);

        factory.setConnectionOptions(options);
        factory.setPersistence(new MemoryPersistence());
        return factory;
    }
}

MQTT消息入站配置

@Slf4j
@Configuration
@IntegrationComponentScan
public class MqttInboundConfiguration {
    @Resource
    private MqttConfig mqttConfig;
    @Resource
    private MqttPahoClientFactory mqttClientFactory;
    @Resource
    private MqttMessageReceiver mqttMessageReceiver;

    @Bean
    public MessageChannel mqttInBoundChannel() {
        return new PublishSubscribeChannel();
    }

    @Bean
    public MessageProducerSupport mqttInbound() {
        MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter(mqttConfig.getClientId(), mqttClientFactory, mqttConfig.getTopic());
        DefaultPahoMessageConverter converter = new DefaultPahoMessageConverter();
        //传输Hex数据，如果是String则可使用默认值false
        converter.setPayloadAsBytes(true);
        adapter.setConverter(converter);
        adapter.setRecoveryInterval(10000);
        adapter.setQos(mqttConfig.getQos());
        adapter.setOutputChannel(mqttInBoundChannel());
        return adapter;
    }

    @Bean
    @ServiceActivator(inputChannel = "mqttInBoundChannel")
    public MessageHandler mqttMessageHandler() {
        return this.mqttMessageReceiver;
    }
}

消费者

@Slf4j
@Component
public class MqttMessageReceiver implements MessageHandler {
    @Resource
    private DataConvertStrategyFactory convertStrategyContext;

    @Override
    public void handleMessage(Message<?> message) throws MessagingException {
        MessageHeaders headers = message.getHeaders();
        String topic = (String) headers.get(MqttHeaders.RECEIVED_TOPIC);
        if (StringUtils.isNotBlank(topic)) {
            return;
        }
        byte[] payload = (byte[]) message.getPayload();
        log.info("topic: {}, message: {}", topic, HexUtils.bytesToHex(payload));
        //从topic中获取clientId，topic的格式：{业务}/{clientId}/{事件标识}
        Map<String, String> map = MqttDataConverter.covertTopic(topic);
        String clientId = map.get("clientId");
        log.info("clientId: {}", clientId);
		//topic中的事件标识
        String eventUrl = map.get("event");
		//自定义的enum，主要用来消息处理消息分组，相同组可以使用相同的数据转换服务
        Event[] events = Event.values();
        String deviceId = clientId;
        Arrays.stream(events).filter(item -> item.getEvent().equals(eventUrl)).findFirst().ifPresent(item -> {
        	//使用策略模式实现
            DataConvertService convertService = convertStrategyContext.getStrategy(item.getGroup());
            convertService.convert(deviceId, eventUrl, payload);
        });
    }
}

数据转换服务接口，具体的数据解析只要实现这个接口就行

public interface DataConvertService {
    /**
     * 转换数据
     *
     * @param clientId 设备SN
     * @param topic  topic
     * @param data  数据
     * @return
     */
    Boolean convert(String clientId, String topic, byte[] data);

    /**
     * 获取转换器
     *
     * @return
     */
    String getConverter();
}

MQTT数据转换策略工厂

@Component
public class DataConvertStrategyFactory implements InitializingBean {
    @Resource
    private List<DataConvertService> handlers;
    private Map<String, DataConvertService> dataConvertServiceMap = new ConcurrentHashMap<>();

    /**
     * 初始化
     */
    @Override
    public void afterPropertiesSet() {
        //进行初始化
        if (CollectionUtils.isNotEmpty(handlers)) {
            handlers.forEach(item -> {
                dataConvertServiceMap.put(item.getConverter(), item);
            });
        }
    }

    /**
     * 返回实际处理对象
     *
     * @param strategy 处理策略
     * @return 实际处理对象
     */
    public DataConvertService getStrategy(String strategy) {
        return dataConvertServiceMap.get(strategy);
    }
}

二、方式2

使用EMQX的Webhook钩子
首先创建钩子函数，把需要监听的事件加上处理逻辑，示例：

@Slf4j
@RequestMapping("/mqtt/client")
@RestController
public class ClientController {
	@PostMapping("/webhook")
	public Result webhook(@RequestBody Map<String, Object> message) {
        log.info("webhook map：{}", message);
        String action = (String) message.get("action");
        String clientid = (String) message.get("clientid");
        if ("client_connected".equals(action)) {
            log.info("client:{} 上线", clientid);
        }
        if ("client_disconnected".equals(action)) {
            log.info("client:{} 下线", clientid);
        }
        if ("message.publish".equals(action)) {
            log.info("已接收到 client:{} 的消息：{}", clientid, message.get("payload"));
        }
        return Result.success("OK");
    }
}

然后在EMQX的Dashboard中创建Webhook，可以选择多个触发器
在这里插入图片描述
填好URL后可以进行测试，之后使用MQTTX进行消息发送测试

控制台输出日志

三、方式3

package com.iinplus.mqtt.handler;

import com.iinplus.mqtt.config.MqttConfig;
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;

@Slf4j
@Component
public class MqttSubscriber implements InitializingBean {
    @Resource
    private MqttConfig config;

    @Override
    public void afterPropertiesSet() {
        try {
            MqttClient client = new MqttClient(config.getUrl(), config.getClientId(), new MemoryPersistence());
            MqttConnectOptions options = new MqttConnectOptions();
            options.setUserName(config.getUsername());
            options.setPassword(config.getPassword().toCharArray());
            options.setCleanSession(true);
            options.setAutomaticReconnect(true);
            options.setConnectionTimeout(0);
            client.connect(options);
            client.subscribe(config.getTopic());
			//设置消息回调
            client.setCallback(new MqttMsgHandler());
        } catch (MqttException e) {
            log.error("MqttException：", e);
        }
    }
}

消息回调处理

@Slf4j
public class MqttMsgHandler implements MqttCallback {
    @Override
    public void connectionLost(Throwable t) {
        // 连接丢失
        log.info("Connection lost：", t);
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) {
        // 接收到消息
        log.info("Message arrived：" + new String(message.getPayload()));
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        // 消息发送成功
        log.info("Delivery complete");
    }
}