本文主要是介绍Mqtt消费端实现的几种方式，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
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://127.0.0.2:1883clientId: "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: 1topic: 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;@Beanpublic 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 {@Resourceprivate MqttConfig mqttConfig;@Resourceprivate MqttPahoClientFactory mqttClientFactory;@Resourceprivate MqttMessageReceiver mqttMessageReceiver;@Beanpublic MessageChannel mqttInBoundChannel() {return new PublishSubscribeChannel();}@Beanpublic 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falseconverter.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 {@Resourceprivate DataConvertStrategyFactory convertStrategyContext;@Overridepublic 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 {@Resourceprivate List<DataConvertService> handlers;private Map<String, DataConvertService> dataConvertServiceMap = new ConcurrentHashMap<>();/*** 初始化*/@Overridepublic 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
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 {@Resourceprivate MqttConfig config;@Overridepublic 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 {@Overridepublic void connectionLost(Throwable t) {// 连接丢失log.info("Connection lost：", t);}@Overridepublic void messageArrived(String topic, MqttMessage message) {// 接收到消息log.info("Message arrived：" + new String(message.getPayload()));}@Overridepublic void deliveryComplete(IMqttDeliveryToken token) {// 消息发送成功log.info("Delivery complete");}
}
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