<!-- 
  spring-boot版本 2.1.0.RELEASE
-->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-integration</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.integration</groupId>
  <artifactId>spring-integration-stream</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.integration</groupId>
  <artifactId>spring-integration-mqtt</artifactId>
</dependency>

# src/main/resources/config/mqtt.properties
##################
#  MQTT 配置
##################
# 用戶名
mqtt.username=admin
# 密碼
mqtt.password=password
# 推送信息的連接地址，如果有多個，用逗號隔開，如：tcp://127.0.0.1:61613,tcp://192.168.1.61:61613
mqtt.url=tcp://127.0.0.1:61613
##################
#  MQTT 生產(chǎn)者
##################
# 連接服務器默認客戶端ID
mqtt.producer.clientId=mqttProducer
# 默認的推送主題，實際可在調用接口時指定
mqtt.producer.defaultTopic=topic1
##################
#  MQTT 消費者
##################
# 連接服務器默認客戶端ID
mqtt.consumer.clientId=mqttConsumer
# 默認的接收主題，可以訂閱多個Topic，逗號分隔
mqtt.consumer.defaultTopic=topic1

import org.apache.commons.lang3.StringUtils;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.core.MessageProducer;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.MessagingException;
/**
 * MQTT配置，生產(chǎn)者
 *
 * @author BBF
 */
@Configuration
public class MqttConfig {
  private static final Logger LOGGER = LoggerFactory.getLogger(MqttConfig.class);
  private static final byte[] WILL_DATA;
  static {
    WILL_DATA = "offline".getBytes();
  }
  /**
   * 訂閱的bean名稱
   */
  public static final String CHANNEL_NAME_IN = "mqttInboundChannel";
  /**
   * 發(fā)布的bean名稱
   */
  public static final String CHANNEL_NAME_OUT = "mqttOutboundChannel";
  @Value("${mqtt.username}")
  private String username;
  @Value("${mqtt.password}")
  private String password;
  @Value("${mqtt.url}")
  private String url;
  @Value("${mqtt.producer.clientId}")
  private String producerClientId;
  @Value("${mqtt.producer.defaultTopic}")
  private String producerDefaultTopic;
  @Value("${mqtt.consumer.clientId}")
  private String consumerClientId;
  @Value("${mqtt.consumer.defaultTopic}")
  private String consumerDefaultTopic;
  /**
   * MQTT連接器選項
   *
   * @return {@link org.eclipse.paho.client.mqttv3.MqttConnectOptions}
   */
  @Bean
  public MqttConnectOptions getMqttConnectOptions() {
    MqttConnectOptions options = new MqttConnectOptions();
    // 設置是否清空session,這里如果設置為false表示服務器會保留客戶端的連接記錄，
    // 這里設置為true表示每次連接到服務器都以新的身份連接
    options.setCleanSession(true);
    // 設置連接的用戶名
    options.setUserName(username);
    // 設置連接的密碼
    options.setPassword(password.toCharArray());
    options.setServerURIs(StringUtils.split(url, ","));
    // 設置超時時間 單位為秒
    options.setConnectionTimeout(10);
    // 設置會話心跳時間 單位為秒 服務器會每隔1.5*20秒的時間向客戶端發(fā)送心跳判斷客戶端是否在線，但這個方法并沒有重連的機制
    options.setKeepAliveInterval(20);
    // 設置“遺囑”消息的話題，若客戶端與服務器之間的連接意外中斷，服務器將發(fā)布客戶端的“遺囑”消息。
    options.setWill("willTopic", WILL_DATA, 2, false);
    return options;
  }
  /**
   * MQTT客戶端
   *
   * @return {@link org.springframework.integration.mqtt.core.MqttPahoClientFactory}
   */
  @Bean
  public MqttPahoClientFactory mqttClientFactory() {
    DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
    factory.setConnectionOptions(getMqttConnectOptions());
    return factory;
  }
  /**
   * MQTT信息通道（生產(chǎn)者）
   *
   * @return {@link org.springframework.messaging.MessageChannel}
   */
  @Bean(name = CHANNEL_NAME_OUT)
  public MessageChannel mqttOutboundChannel() {
    return new DirectChannel();
  }
  /**
   * MQTT消息處理器（生產(chǎn)者）
   *
   * @return {@link org.springframework.messaging.MessageHandler}
   */
  @Bean
  @ServiceActivator(inputChannel = CHANNEL_NAME_OUT)
  public MessageHandler mqttOutbound() {
    MqttPahoMessageHandler messageHandler = new MqttPahoMessageHandler(
        producerClientId,
        mqttClientFactory());
    messageHandler.setAsync(true);
    messageHandler.setDefaultTopic(producerDefaultTopic);
    return messageHandler;
  }
  /**
   * MQTT消息訂閱綁定（消費者）
   *
   * @return {@link org.springframework.integration.core.MessageProducer}
   */
  @Bean
  public MessageProducer inbound() {
    // 可以同時消費（訂閱）多個Topic
    MqttPahoMessageDrivenChannelAdapter adapter =
        new MqttPahoMessageDrivenChannelAdapter(
            consumerClientId, mqttClientFactory(),
            StringUtils.split(consumerDefaultTopic, ","));
    adapter.setCompletionTimeout(5000);
    adapter.setConverter(new DefaultPahoMessageConverter());
    adapter.setQos(1);
    // 設置訂閱通道
    adapter.setOutputChannel(mqttInboundChannel());
    return adapter;
  }
  /**
   * MQTT信息通道（消費者）
   *
   * @return {@link org.springframework.messaging.MessageChannel}
   */
  @Bean(name = CHANNEL_NAME_IN)
  public MessageChannel mqttInboundChannel() {
    return new DirectChannel();
  }
  /**
   * MQTT消息處理器（消費者）
   *
   * @return {@link org.springframework.messaging.MessageHandler}
   */
  @Bean
  @ServiceActivator(inputChannel = CHANNEL_NAME_IN)
  public MessageHandler handler() {
    return new MessageHandler() {
      @Override
      public void handleMessage(Message<?> message) throws MessagingException {
        LOGGER.error("===================={}============", message.getPayload());
      }
    };
  }
}

import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.stereotype.Component;
/**
 * MQTT生產(chǎn)者消息發(fā)送接口
 * <p>MessagingGateway要指定生產(chǎn)者的通道名稱</p>
 * @author BBF
 */
@Component
@MessagingGateway(defaultRequestChannel = MqttConfig.CHANNEL_NAME_OUT)
public interface IMqttSender {
  /**
   * 發(fā)送信息到MQTT服務器
   *
   * @param data 發(fā)送的文本
   */
  void sendToMqtt(String data);
  /**
   * 發(fā)送信息到MQTT服務器
   *
   * @param topic 主題
   * @param payload 消息主體
   */
  void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic,
      String payload);
  /**
   * 發(fā)送信息到MQTT服務器
   *
   * @param topic 主題
   * @param qos 對消息處理的幾種機制。
 0 表示的是訂閱者沒收到消息不會再次發(fā)送，消息會丟失。

   * 1 表示的是會嘗試重試，一直到接收到消息，但這種情況可能導致訂閱者收到多次重復消息。

   * 2 多了一次去重的動作，確保訂閱者收到的消息有一次。
   * @param payload 消息主體
   */
  void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic,
      @Header(MqttHeaders.QOS) int qos,
      String payload);
}

/**
 * MQTT消息發(fā)送
 *
 * @author BBF
 */
@Controller
@RequestMapping(value = "/")
public class MqttController {
  /**
   * 注入發(fā)送MQTT的Bean
   */
  @Resource
  private IMqttSender iMqttSender;
  /**
   * 發(fā)送MQTT消息
   * @param message 消息內容
   * @return 返回
   */
  @ResponseBody
  @GetMapping(value = "/mqtt", produces ="text/html")
  public ResponseEntity<String> sendMqtt(@RequestParam(value = "msg") String message) {
    iMqttSender.sendToMqtt(message);
    return new ResponseEntity<>("OK", HttpStatus.OK);
  }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.context.annotation.PropertySource;
/**
 * SpringBoot 入口類
 *
 * @author BBF
 */
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class,
    HibernateJpaAutoConfiguration.class})
@PropertySource(encoding = "UTF-8", value = {"classpath:config/mqtt.properties"})
public class Application {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}