### 业务场景硬件采集的数据传入MQTT(这边MQTT的服务器用的是EMQX，有兴趣的可以自己去了解一下)，JAVA通过代码连接MQTT服务器，对数据进行处理 ### 新建SpringBoot项目，pom文件中直接引入下面MQTT的依赖 ```java org.springframework.integration spring-integration-stream org.springframework.boot spring-boot-starter-integration org.springframework.integration spring-integration-mqtt ``` ### MQTT工具类 #### MqttServerData 因为是多连接，所以说MQTT的配置需要存放在数据库中，需要新增MQTT基础表MqttServerData，我这边用的是Spring Data JPA，大家可以用自己的ORM框架生成这些基础表的信息 ```java package com.huibo.xx.xx.entity; import com.huibo.core.entity.BaseEntity; import lombok.Data; import lombok.EqualsAndHashCode; import javax.persistence.Entity; /** * @author ：cola * @description： Mqtt配置表 * @date ：2023/7/18 8:51 */ @Data @Entity @EqualsAndHashCode(callSuper = true) public class MqttServerData extends BaseEntity { private String serverHost; private String serverPort; private String userName; private String password; private String clientId; /** * mqtt订阅的主体，以“，”隔开 */ private String clientTopic; /** * 客户端每次重连是否清除session */ private String clientCleanSession; private String remark; private Boolean enableFlag; } ``` #### MqttServerDataRepository ```java package com.xx.xx.mqtt.repository; import com.xx.xx.mqtt.entity.MqttServerData; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.data.jpa.repository.JpaSpecificationExecutor; public interface MqttServerDataRepository extends JpaRepository, JpaSpecificationExecutor findByList(MqttServerDataQueryDto queryDto); Page findByPage(MqttServerDataQueryDto queryDto, Pageable page); /** * 初始化MQTT连接 * * @param response 响应体 */ void initMqttServer(MqttServerData mqttServerData) throws MqttException; } ``` #### MqttServerDataServiceImpl ```java /** * @author cola * @date 2023/7/13 16:23 */ @Service @Slf4j public class MqttServerDataServiceImpl implements MqttServerDataService { @Autowired private MqttServerDataRepository mqttServerDataRepository; @Autowired private ExcelHandler excelHandler; @Override public MqttServerData add(MqttServerDataAddDto addDto) { MqttServerData mqttServerData = mqttServerDataRepository.save(from(addDto)); if (mqttServerData.getEnableFlag()) { this.initMqttServer(mqttServerData); } return mqttServerData; } @Override @Transactional public boolean update(MqttServerDataUpdateDto updateDto) throws MqttException { MqttServerData entity = findById(updateDto.getId()); assemble(entity, updateDto); if (!entity.getEnableFlag() && updateDto.getEnableFlag()) { if (!MqttClientListener.mqttClients.containsKey(entity.getId().toString())) { this.initMqttServer(entity); } else { } } if (entity.getEnableFlag() && !updateDto.getEnableFlag()) { MqttClientConnect mqttClientConnect = MqttClientListener.mqttClients.get(entity.getId().toString()); mqttClientConnect.close(); } return true; } @Override public MqttServerData findById(Long id) { return mqttServerDataRepository.findById(id).orElseThrow(() -> new NoEntityFoundException("No record found by id = " + id)); } @Override @Transactional public boolean delete(Long id) throws MqttException { MqttServerData entity = findById(id); entity.setDeleted(true); MqttClientConnect mqttClientConnect = MqttClientListener.mqttClients.get(entity.getId().toString()); if (Objects.nonNull(mqttClientConnect)) { mqttClientConnect.close(); } return true; } @Override public List findByList(MqttServerDataQueryDto queryDto) { return mqttServerDataRepository.findAll(getSpecification(queryDto)); } @Override public Page findByPage(MqttServerDataQueryDto queryDto, Pageable page) { return mqttServerDataRepository.findAll(getSpecification(queryDto), page); } @Override public void initMqttServer(MqttServerData mqttServerData) { try { MqttClientConnect mqttClientConnect = new MqttClientConnect(); mqttClientConnect.setMqttClientId(String.valueOf(mqttServerData.getId())); String host = "tcp://" + mqttServerData.getServerHost() + ":" + mqttServerData.getServerPort(); mqttClientConnect.setMqttClient(host, String.valueOf(mqttServerData.getId()), mqttServerData.getUserName(), mqttServerData.getPassword(), new MqttClientCallback(String.valueOf(mqttServerData.getId()))); //订阅CPUId mqttClientConnect.sub(String.format(DEVICE_DOWN_TOPIC, ServerUtil.getCPUSerial())); MqttClientListener.mqttClients.put(String.valueOf(mqttServerData.getId()), mqttClientConnect); log.info("{}--连接成功！！订阅主题--{}", mqttServerData.getId(), mqttServerData.getClientTopic()); } catch (MqttException e) { e.printStackTrace(); } } @Override public void addSubTopicForDevice(Device device) { MqttClientListener.mqttClients.forEach((key, value) -> { try { value.sub(String.format(DEVICE_DOWN_TOPIC, device.getName())); } catch (MqttException e) { e.printStackTrace(); } }); } private MqttServerData from(MqttServerDataAddDto dto) { MqttServerData entity = new MqttServerData(); BeanUtils.copyProperties(dto, entity); entity.setClientTopic("/topic/default"); return entity; } private void assemble(MqttServerData entity, MqttServerDataUpdateDto updateDto) { BeanUtils.copyProperties(updateDto, entity); } private Specification getSpecification(MqttServerDataQueryDto queryDto) { return (root, query, builder) -> { List predicates = Lists.newArrayList(); if (!StringUtils.isEmpty(queryDto.getServerHost())) { predicates.add(builder.like(root.get("serverHost"), "%".concat(queryDto.getServerHost()).concat("%"))); } if (Objects.nonNull(queryDto.getEnableFlag())) { predicates.add(builder.isTrue(root.get("enableFlag"))); } predicates.add(builder.isFalse(root.get("isDeleted"))); return builder.and(predicates.toArray(new Predicate[0])); }; } } ``` #### MqttClientListener 项目启动，监听主题 ```java package com.huibo.acquisition.mqtt.listener; import com.xx.xx.mqtt.config.MqttClientConnect; import com.xx.xx.acquisition.mqtt.controller.dto.MqttServerDataQueryDto; import com.xx.xx.acquisition.mqtt.entity.MqttServerData; import com.xx.xx.acquisition.mqtt.service.MqttServerDataService; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.ApplicationListener; import org.springframework.context.event.ContextRefreshedEvent; import org.springframework.stereotype.Component; import org.springframework.util.CollectionUtils; import java.util.List; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.atomic.AtomicBoolean; /** * @author ：cola * @description：项目启动监听主题 * @date ：2023/7/18 10:53 */ @Slf4j @Component public class MqttClientListener implements ApplicationListener { @Autowired private MqttServerDataService mqttServerDataService; /** * 客户端 */ public static ConcurrentHashMap mqttClients = new ConcurrentHashMap(); private final AtomicBoolean isInit = new AtomicBoolean(false); @Override public void onApplicationEvent(ContextRefreshedEvent event) { //防止重复触发 if (!isInit.compareAndSet(false, true)) { return; } //TODO 需要传入启用参数 List mqttServers = mqttServerDataService.findByList(new MqttServerDataQueryDto() {{ setEnableFlag(Boolean.TRUE); }}); try { if (!CollectionUtils.isEmpty(mqttServers)) { for (MqttServerData mqttServerData : mqttServers) { mqttServerDataService.initMqttServer(mqttServerData); } } } catch (Exception e) { log.error(e.getMessage(), e); } } } ``` #### MqttClientConnect ```java package com.xx.xx.mqtt.config; import com.huibo.acquisition.mqtt.callback.MqttClientCallback; import lombok.extern.slf4j.Slf4j; import org.eclipse.paho.client.mqttv3.*; import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence; import org.springframework.stereotype.Component; import java.io.UnsupportedEncodingException; /** * @author ：cola * @description： Mqtt * @date ：2023/7/18 10:33 */ @Slf4j @Component public class MqttClientConnect { private MqttClient mqttClient; /** * 系统的mqtt客户端id */ private String mqttClientId; /** * 客户端connect连接mqtt服务器 * * @param userName 用户名 * @param passWord 密码 * @param mqttCallback 回调函数 **/ public void setMqttClient(String host, String clientId, String userName, String passWord, MqttCallback mqttCallback) throws MqttException { // 连接设置 MqttConnectOptions options = mqttConnectOptions(host, clientId, userName, passWord); if (mqttCallback == null) { mqttClient.setCallback(new MqttClientCallback(mqttClientId)); } else { mqttClient.setCallback(mqttCallback); } mqttClient.connect(options); } /** * MQTT连接参数设置 */ private MqttConnectOptions mqttConnectOptions(String host, String clientId, String userName, String passWord) throws MqttException { // 创建 MQTT 客户端对象 mqttClient = new MqttClient(host, clientId, new MemoryPersistence()); // 连接设置 MqttConnectOptions options = new MqttConnectOptions(); // 设置连接用户名 options.setUserName(userName); // 设置连接密码 options.setPassword(passWord.toCharArray()); // 设置超时时间，单位为秒 options.setConnectionTimeout(30); // 设置心跳时间单位为秒，表示服务器每 30 秒向客户端发送心跳判断客户端是否在线 options.setKeepAliveInterval(30); // 设置遗嘱消息的话题，若客户端和服务器之间的连接意外断开，服务器将发布客户端的遗嘱信息 options.setWill("willTopic", (mqttClientId + "与服务器断开连接").getBytes(), 0, false); // 断线自动重连 options.setAutomaticReconnect(true); // 是否清空 session，设置为 false 表示服务器会保留客户端的连接记录，客户端重连之后能获取到服务器在客户端断开连接期间推送的消息 // 设置为 true 表示每次连接到服务端都是以新的身份 options.setCleanSession(true); return options; } /** * 关闭MQTT连接 */ public void close() throws MqttException { mqttClient.close(); mqttClient.disconnect(); } /** * 向某个主题发布消息默认qos：1 * * @param topic:发布的主题 * @param msg：发布的消息 */ public void pub(String topic, String msg) throws MqttException { MqttMessage mqttMessage = new MqttMessage(); //mqttMessage.setQos(2); try { mqttMessage.setPayload(msg.getBytes("UTF-8")); } catch (UnsupportedEncodingException e) { log.error(e.getMessage()); } MqttTopic mqttTopic = mqttClient.getTopic(topic); MqttDeliveryToken token = mqttTopic.publish(mqttMessage); token.waitForCompletion(); } /** * 向某个主题发布消息 * * @param topic: 发布的主题 * @param msg: 发布的消息 * @param qos: 消息质量 Qos：0、1、2 */ public void pub(String topic, String msg, int qos) throws MqttException { MqttMessage mqttMessage = new MqttMessage(); mqttMessage.setQos(qos); mqttMessage.setPayload(msg.getBytes()); MqttTopic mqttTopic = mqttClient.getTopic(topic); MqttDeliveryToken token = mqttTopic.publish(mqttMessage); token.waitForCompletion(); } /** * 订阅多个主题，此方法默认的的Qos等级为：1 * * @param topic 主题 */ public void sub(String[] topic) throws MqttException { mqttClient.subscribe(topic); } /** * 订阅一个个主题，此方法默认的的Qos等级为：1 * * @param topic 主题 */ public void sub(String topic) throws MqttException { mqttClient.subscribe(topic); } /** * 订阅某一个主题，可携带Qos * * @param topic 所要订阅的主题 * @param qos 消息质量：0、1、2 */ public void sub(String topic, int qos) throws MqttException { mqttClient.subscribe(topic, qos); } public String getMqttClientId() { return mqttClientId; } public void setMqttClientId(String mqttClientId) { this.mqttClientId = mqttClientId; } } ``` #### MqttClientCallback Mqtt的回调 ```java package com.huibo.acquisition.mqtt.callback; import com.huibo.acquisition.mqtt.listener.MqttClientListener; import com.huibo.acquisition.service.DeviceService; import com.huibo.acquisition.utils.ApplicationContextUtil; import com.huibo.acquisition.utils.ServerUtil; import lombok.extern.slf4j.Slf4j; import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken; import org.eclipse.paho.client.mqttv3.MqttCallbackExtended; import org.eclipse.paho.client.mqttv3.MqttException; import org.eclipse.paho.client.mqttv3.MqttMessage; import java.nio.charset.StandardCharsets; import static com.huibo.acquisition.constant.GlobalConstant.DEVICE_DOWN_TOPIC; /** * @author ：cola * @description：Mqtt的回调 * @date ：2023/7/18 10:43 */ @Slf4j public class MqttClientCallback implements MqttCallbackExtended { /** * 系统的mqtt客户端id */ private String mqttClientId; public MqttClientCallback(String mqttClientId) { this.mqttClientId = mqttClientId; } /** * TODO subscribe订阅后得到的消息会执行到这里 */ @Override public void messageArrived(String topic, MqttMessage message) { String data = new String(message.getPayload(), StandardCharsets.UTF_8); System.out.printf("接收消息主题: %s%n", topic); System.out.printf("接收消息Qos: %d%n", message.getQos()); // message.toString() 也可以拿到消息内容 System.out.printf("接收消息内容: %s%n", data); System.out.printf("接收消息retained: %b%n", message.isRetained()); //处理消息 ApplicationContextUtil.getBean(DeviceService.class).handleMqttMessage(data); } /** * MQTT 断开连接会执行此方法 */ @Override public void connectionLost(Throwable cause) { log.info("断开了MQTT连接：{}", cause.getMessage()); } /** * publish发布成功后会执行到这里 */ @Override public void deliveryComplete(IMqttDeliveryToken token) { log.info("发布消息成功"); } @Override public void connectComplete(boolean reconnect, String serverURI) { MqttClientListener.mqttClients.forEach((k, v) -> { try { log.info("Mqtt重连成功：" + v.getMqttClientId() + " 已连接"); v.sub(String.format(DEVICE_DOWN_TOPIC, ServerUtil.getCPUSerial())); } catch (MqttException e) { e.printStackTrace(); } }); } } ```