springboot emqx 搭建环境

以下是在Windows环境下使用Spring Boot和EMQ X搭建MQTT消息代理的步骤：

1. 下载EMQ X
从EMQ X官网下载最新版本的EMQ X，解压缩到本地目录。

2. 创建Spring Boot项目
在IDE中创建一个新的Spring Boot项目。

3. 添加EMQ X依赖
在pom.xml文件中添加EMQ X的依赖：

   <dependency>
       <groupId>org.eclipse.paho</groupId>
       <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
       <version>1.2.5</version>
   </dependency>

4. 配置EMQ X
在application.properties文件中添加以下配置：

   mqtt.host=tcp://localhost:1883
   mqtt.username=admin
   mqtt.password=public

5. 编写代码
在Spring Boot项目中编写代码，连接到EMQ X代理并发布和订阅MQTT消息。

   import org.eclipse.paho.client.mqttv3.MqttClient;
   import org.eclipse.paho.client.mqttv3.MqttConnectOptions;   import org.eclipse.paho.client.mqttv3.MqttException;
   import org.eclipse.paho.client.mqttv3.MqttMessage;
   import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
   import org.springframework.beans.factory.annotation.Value;
   import org.springframework.stereotype.Component;

   @Component
   public class MqttClientWrapper {

       @Value("${mqtt.host}")
       private String host;

       @Value("${mqtt.username}")
       private String username;

       @Value("${mqtt.password}")
       private String password;

       private MqttClient client;

       public void connect() throws MqttException {
           String clientId = MqttClient.generateClientId();
           MemoryPersistence persistence = new MemoryPersistence();
           client = new MqttClient(host, clientId, persistence);

           MqttConnectOptions connOpts = new MqttConnectOptions();
           connOpts.setUserName(username);
           connOpts.setPassword(password.toCharArray());

           client.connect(connOpts);
       }

       public void publish(String topic, String content) throws MqttException {
           MqttMessage message = new MqttMessage(content.getBytes());
           message.setQos(2);
           client.publish(topic, message);
       }

       public void subscribe(String topic) throws MqttException {
           client.subscribe(topic, 2);
       }

       public void disconnect() throws MqttException {
           client.disconnect();
       }
   }

6. 运行应用程序
运行Spring Boot应用程序并测试连接到EMQ X代理。