SpringBoot+MQTT+apollo实现订阅发布功能的示例

  <!-- MQTT -->
  <dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-stream</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-mqtt</artifactId>
  </dependency>

mqtt:
 username: admin
 password: password
 host-url: tcp://127.0.0.1:8161 # 你自己服务器的地址和端口，这个需要改
 clientID: test1    # 这个改不改随意，但不同的客户端肯定不能一样
 default-topic: home/garden/fountain   # 默认主题
 timeout: 100
 keepalive: 100

# Tomcat
server:
 tomcat:
  uri-encoding: UTF-8
  max-threads: 1000
  min-spare-threads: 30
 port: 8088

@Component
@ConfigurationProperties("mqtt")
@Setter
@Getter
public class MqttConfig {
  @Autowired
  private MqttPushClient mqttPushClient;

  /**
   * 用户名
   */
  // @Value("username")
  private String username;
  /**
   * 密码
   */
  private String password;
  /**
   * 连接地址
   */
  private String hostUrl;
  /**
   * 客户Id
   */
  private String clientID;
  /**
   * 默认连接话题
   */
  private String defaultTopic;
  /**
   * 超时时间
   */
  private int timeout;
  /**
   * 保持连接数
   */
  private int keepalive;

  @Bean
  public MqttPushClient getMqttPushClient() {
    System.out.println("hostUrl: "+ hostUrl);
    System.out.println("clientID: "+ clientID);
    System.out.println("username: "+ username);
    System.out.println("password: "+ password);
    System.out.println("timeout: "+timeout);
    System.out.println("keepalive: "+ keepalive);
    mqttPushClient.connect(hostUrl, clientID, username, password, timeout, keepalive);
    // 以/#结尾表示订阅所有以test开头的主题
    mqttPushClient.subscribe(defaultTopic, 0);
    return mqttPushClient;
  }
}

@Component
public class MqttPushClient {
  private static final Logger logger = LoggerFactory.getLogger(MqttPushClient.class);

  @Autowired
  private PushCallback pushCallback;

  private static MqttClient client;

  private static MqttClient getClient() {
    return client;
  }

  private static void setClient(MqttClient client) {
    MqttPushClient.client = client;
  }

  /**
   * 客户端连接
   *
   * @param host   ip+端口
   * @param clientID 客户端Id
   * @param username 用户名
   * @param password 密码
   * @param timeout  超时时间
   * @param keepalive 保留数
   */
  public void connect(String host, String clientID, String username, String password, int timeout, int keepalive) {
    MqttClient client;
    try {
      client = new MqttClient(host, clientID, new MemoryPersistence());
      MqttConnectOptions options = new MqttConnectOptions();
      options.setCleanSession(true);
      options.setUserName(username);
      options.setPassword(password.toCharArray());
      options.setConnectionTimeout(timeout);
      options.setKeepAliveInterval(keepalive);
      MqttPushClient.setClient(client);
      try {
        client.setCallback(pushCallback);
        client.connect(options);
      } catch (Exception e) {
        e.printStackTrace();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * 发布
   *
   * @param qos     连接方式
   * @param retained  是否保留
   * @param topic    主题
   * @param pushMessage 消息体
   */
  public void publish(int qos, boolean retained, String topic, String pushMessage) {
    MqttMessage message = new MqttMessage();
    message.setQos(qos);
    message.setRetained(retained);
    message.setPayload(pushMessage.getBytes());
    MqttTopic mTopic = MqttPushClient.getClient().getTopic(topic);
    if (null == mTopic) {
      logger.error("topic not exist");
    }
    MqttDeliveryToken token;
    try {
      token = mTopic.publish(message);
      token.waitForCompletion();
    } catch (MqttPersistenceException e) {
      e.printStackTrace();
    } catch (MqttException e) {
      e.printStackTrace();
    }
  }

  /**
   * 订阅某个主题
   *
   * @param topic 主题
   * @param qos  连接方式
   */
  public void subscribe(String topic, int qos) {
    logger.info("开始订阅主题" + topic);
    try {
      MqttPushClient.getClient().subscribe(topic, qos);
    } catch (MqttException e) {
      e.printStackTrace();
    }
  }
}

@RestController
@RequestMapping("/")
public class TestController {

  @Autowired
  private MqttPushClient mqttPushClient;

  @GetMapping(value = "/publishTopic")
  public String publishTopic() {
    String topicString = "home/garden/fountain";
    mqttPushClient.publish(0, false, topicString, "测试一下发布消息");
    return "ok";
  }
  // 发送自定义消息内容（使用默认主题）
  @RequestMapping("/publishTopic/{data}")
  public String test1(@PathVariable("data") String data) {
    String topicString = "home/garden/fountain";
    mqttPushClient.publish(0,false,topicString, data);
    return "ok";
  }

  // 发送自定义消息内容，且指定主题
  @RequestMapping("/publishTopic/{topic}/{data}")
  public String test2(@PathVariable("topic") String topic, @PathVariable("data") String data) {
    mqttPushClient.publish(0,false,topic, data);
    return "ok";
  }
}