Spring Boot需要与硬件设备进行交互
,使用MQTT
作为通信协议。对于这种情况,MQTT
的服务端(Broker)
需要在服务器上安装和配置,硬件设备和Java应用程序(Spring Boot)通过该Broker进行消息的发布和订阅
。以下是详细步骤:
一、服务器安装步骤
安装 Mosquitto (MQTT Broker)
Ubuntu:
shell
# 更新软件包列表
sudo apt-get update
# 安装 Mosquitto 及其客户端工具
sudo apt-get install mosquitto mosquitto-clients
# 配置 Mosquitto 开机自启动
sudo systemctl enable mosquitto
# 启动 Mosquitto 服务
sudo systemctl start mosquitto
CentOS:
shell
# 更新软件包列表
sudo yum update
# 安装 EPEL 仓库
sudo yum install epel-release
# 安装 Mosquitto
sudo yum install mosquitto
# 配置 Mosquitto 开机自启动
sudo systemctl enable mosquitto
# 启动 Mosquitto 服务
sudo systemctl start mosquitto
配置 Mosquitto(可选)
默认情况下,Mosquitto
允许匿名连接,但为了安全性,可以配置用户名和密码。在 /etc/mosquitto/mosquitto.conf
文件中进行配置:
shell
# 启用监听1883端口
listener 1883
# 允许匿名访问
allow_anonymous true
二、Spring Boot 配置和工具类
添加依赖
在pom.xml
文件中添加以下依赖:
java
<dependency>
<groupId>org.springframework.integration</groupId>
<artifactId>spring-integration-mqtt</artifactId>
</dependency>
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
</dependency>
application.yml配置
可以将所有MQTT
相关的配置,包括client_id
和默认主题
,配置在application.yml
中
yaml
mqtt:
broker:
# 设备MQTT应用配置
url: tcp://your_server_ip:1883
username: your_username
password: your_password
# 自定义约定client_id
clientId: your_client_id
topics:
# 默认监听
default: your/default_topic
# 自定义监听
subscriptions:
- your/topic1
- your/topic2
配置类
创建一个 MqttConfig
配置类:
java
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
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.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.beans.factory.annotation.Autowired;
@Configuration
public class MqttConfig {
@Autowired
private MqttUtil mqttUtil;
@Value("${mqtt.broker.url}")
private String brokerUrl;
@Value("${mqtt.broker.username}")
private String username;
@Value("${mqtt.broker.password}")
private String password;
@Value("${mqtt.broker.clientId}")
private String clientId;
@Value("${mqtt.topics.default}")
private String defaultTopic;
@Value("${mqtt.topics.subscriptions}")
private String[] topics;
// 配置MQTT客户端工厂
@Bean
public MqttPahoClientFactory mqttClientFactory() {
DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
MqttConnectOptions options = new MqttConnectOptions();
options.setServerURIs(new String[]{brokerUrl});
options.setUserName(username);
options.setPassword(password.toCharArray());
factory.setConnectionOptions(options);
return factory;
}
// (接收消息:步骤一)定义一个消息通道,用于接收消息
@Bean
public MessageChannel mqttInputChannel() {
return new DirectChannel();
}
// (接收消息:步骤二)配置消息驱动通道适配器,用于接收指定主题的消息
@Bean
public MessageProducer inbound() {
MqttPahoMessageDrivenChannelAdapter adapter =
new MqttPahoMessageDrivenChannelAdapter(clientId, mqttClientFactory(), topics);
adapter.setOutputChannel(mqttInputChannel());
return adapter;
}
// (接收消息:步骤三)配置消息处理器,用于处理接收到的消息
@Bean
@ServiceActivator(inputChannel = "mqttInputChannel")
public MessageHandler handler() {
return message -> {
String topic = message.getHeaders().get("mqtt_receivedTopic").toString();
String payload = message.getPayload().toString();
System.out.println("接收到消息: 主题 = " + topic + ", 内容 = " + payload);
// 发布接收到的消息事件
mqttUtil.publishReceivedMessage(topic, payload);
};
}
// 配置MQTT消息发送处理器
@Bean
@ServiceActivator(inputChannel = "mqttOutboundChannel")
public MessageHandler mqttOutbound() {
MqttPahoMessageHandler messageHandler =
new MqttPahoMessageHandler(clientId, mqttClientFactory());
messageHandler.setAsync(true);
messageHandler.setDefaultTopic(defaultTopic); // 设置默认主题
return messageHandler;
}
// 定义一个消息通道,用于发送消息
@Bean
public MessageChannel mqttOutboundChannel() {
return new DirectChannel();
}
}
MQTT 工具类
创建一个 MqttUtil
工具类:
java
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
@Component
public class MqttUtil {
@Autowired
private MessageChannel mqttOutboundChannel;
@Autowired
private ApplicationEventPublisher eventPublisher;
/**
* 发送消息到默认主题
* @param payload 消息内容
*/
public void sendMessage(String payload) {
mqttOutboundChannel.send(MessageBuilder.withPayload(payload).build());
}
/**
* 发送消息到指定主题
* @param topic 主题
* @param payload 消息内容
*/
public void sendMessage(String topic, String payload) {
mqttOutboundChannel.send(MessageBuilder.withPayload(payload)
.setHeader("mqtt_topic", topic)
.build());
}
/**
* (接收消息:步骤四)发布接收到的MQTT消息事件
* @param topic 主题
* @param payload 消息内容
*/
public void publishReceivedMessage(String topic, String payload) {
MqttMessageEvent event = new MqttMessageEvent(this, topic, payload);
eventPublisher.publishEvent(event);
}
}
MQTT 消息事件( MqttUtil.publishReceivedMessage() 方法使用)
创建一个事件类,用于封装接收到的MQTT
消息:
java
import org.springframework.context.ApplicationEvent;
public class MqttMessageEvent extends ApplicationEvent {
private final String topic;
private final String payload;
public MqttMessageEvent(Object source, String topic, String payload) {
super(source);
this.topic = topic;
this.payload = payload;
}
public String getTopic() {
return topic;
}
public String getPayload() {
return payload;
}
}
消息监听器( MqttUtil.publishReceivedMessage() 方法使用)
创建一个监听器,用于处理接收到的MQTT
消息:
java
import org.springframework.context.event.EventListener;
import org.springframework.stereotype.Component;
@Component
public class MqttMessageListener {
/**
* (接收消息:步骤五)事件监听器中处理消息
* 说明:此方法将接收到上方 MqttUtil.publishReceivedMessage() 发布的事件并处理这些消息
* @param event 接收到的事件
*/
@EventListener
public void handleMqttMessage(MqttMessageEvent event) {
String topic = event.getTopic();
String payload = event.getPayload();
System.out.println("处理接收到的消息: 主题 = " + topic + ", 内容 = " + payload);
// 根据不同的主题进行不同的处理
if ("your/topic1".equals(topic)) {
handleTopic1Message(payload);
} else if ("your/topic2".equals(topic)) {
handleTopic2Message(payload);
}
}
private void handleTopic1Message(String payload) {
// 处理来自 topic1 的消息
System.out.println("处理 topic1 消息: " + payload);
}
private void handleTopic2Message(String payload) {
// 处理来自 topic2 的消息
System.out.println("处理 topic2 消息: " + payload);
}
}
使用示例
在你的Spring Boot应用中,可以通过注入MqttUtil
来发送消息:
java
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class MqttController {
@Autowired
private MqttUtil mqttUtil;
@GetMapping("/send")
public String sendMessage() {
mqttUtil.sendMessage("your/topic1", "Hello from Spring Boot");
return "Message sent!";
}
}
运行流程
- 1.在
application.yml
文件中配置MQTT
服务器的URL、用户名、密码、client_id、默认主题和订阅的主题
。 - 2.启动
MQTT Broker(如Mosquitto)
。 - 3.确保硬件设备连接到
MQTT Broker
,并发布和订阅消息。 - 4.启动Spring Boot应用程序,确保它可以
发送
和接收MQTT
消息。 - 5.在控制台中查看接收到的消息,并根据不同的主题进行处理。
通过以上步骤,你可以在Spring Boot
中配置和使用MQTT
,并将其封装为工具类和事件监听机制,方便其他项目集成和使用。这种配置方式使得MQTT
连接认证更加安全,代码更加灵活。
30岁终于买了一台不卡的电脑,可 坐在电脑前我的 却卡住了...