开始研究JAVA及MQTT，写下该文章方便使用参考
1、添加依赖 pom.xml
<dependency>
<groupId>org.springframework.integration</groupId>
<artifactId>spring-integration-stream</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.integration</groupId>
<artifactId>spring-integration-mqtt</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.35</version>
</dependency>
2、mqtt配置 application.yml
# Spring配置
spring:
# MQTT
mqtt:
# 服务器连接地址，如果有多个，用逗号隔开
host: tcp://192.168.1.1:1883
# 连接服务器默认客户端ID
clientId: mqtt_jlsId_
# 默认的消息推送主题，实际可在调用接口时指定
topic: topic_a,topic_b,topic_c
# 用户名
username:
# 密码
password:
# 连接超时
timeout: 30
# 心跳
keepalive: 30
3、获取配置信息工具类
当然可以使用注解 @Value获取配置信息
这里是网上查的资料直接使用以下类来获取
package com.projuct.junlaishun.mqtt;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
/**
* 获取配置信息
**/
public class PropertiesUtil {
public static String MQTT_HOST;
public static String MQTT_CLIENT_ID;
public static String MQTT_USER_NAME;
public static String MQTT_PASSWORD;
public static String MQTT_TOPIC;
public static Integer MQTT_TIMEOUT;
public static Integer MQTT_KEEP_ALIVE;
/**
* mqtt配置
*/
static {
Properties properties = loadMqttProperties();
MQTT_HOST = properties.getProperty("host");
MQTT_CLIENT_ID = properties.getProperty("clientId")+Math.random();
MQTT_USER_NAME = properties.getProperty("username");
MQTT_PASSWORD = properties.getProperty("password");
MQTT_TOPIC = properties.getProperty("topic");
MQTT_TIMEOUT = Integer.valueOf(properties.getProperty("timeout"));
MQTT_KEEP_ALIVE = Integer.valueOf(properties.getProperty("keepalive"));
}
private static Properties loadMqttProperties() {
InputStream inputstream = PropertiesUtil.class.getResourceAsStream("/application.yml");
Properties properties = new Properties();
try {
properties.load(inputstream);
return properties;
} catch (IOException e) {
throw new RuntimeException(e);
} finally {
try {
if (inputstream != null) {
inputstream.close();
}
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
}
4、MQTT客户端 MqttConsumer类
package com.projuct.junlaishun.mqtt;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;
@Component
public class MqttConsumer implements ApplicationRunner {
private static MqttClient client;
@Override
public void run(ApplicationArguments args) {
System.out.println("初始化并启动mqtt......");
this.connect();
}
/**
* 连接mqtt服务器
*/
private void connect() {
try {
// 1 创建客户端
getClient();
// 2 设置配置
MqttConnectOptions options = getOptions();
String[] topic = PropertiesUtil.MQTT_TOPIC.split(",");
// 3 消息发布质量
int[] qos = getQos(topic.length);
// 4 最后设置
create(options, topic, qos);
} catch (Exception e) {
System.out.println("mqtt连接异常：" + e);
}
}
/**
* 创建客户端 --- 1 ---
*/
public void getClient() {
try {
if (null == client) {
client = new MqttClient(PropertiesUtil.MQTT_HOST, PropertiesUtil.MQTT_CLIENT_ID, new MemoryPersistence());
}
System.out.println("创建mqtt客户端：" );
} catch (Exception e) {
System.out.println("创建mqtt客户端异常：\" + e：" );
}
}
/**
* 生成配置对象，用户名，密码等 --- 2 ---
*/
public MqttConnectOptions getOptions() {
MqttConnectOptions options = new MqttConnectOptions();
options.setUserName(PropertiesUtil.MQTT_USER_NAME);
options.setPassword(PropertiesUtil.MQTT_PASSWORD.toCharArray());
// 设置超时时间
options.setConnectionTimeout(PropertiesUtil.MQTT_TIMEOUT);
// 设置会话心跳时间
options.setKeepAliveInterval(PropertiesUtil.MQTT_KEEP_ALIVE);
// 是否清除session
options.setCleanSession(false);
System.out.println("--生成mqtt配置对象");
return options;
}
/**
* qos --- 3 ---
*/
public int[] getQos(int length) {
int[] qos = new int[length];
for (int i = 0; i < length; i++) {
/**
* MQTT协议中有三种消息发布服务质量:
*
* QOS0： “至多一次”，消息发布完全依赖底层 TCP/IP 网络。会发生消息丢失或重复。这一级别可用于如下情况，环境传感器数据，丢失一次读记录无所谓，因为不久后还会有第二次发送。
* QOS1： “至少一次”，确保消息到达，但消息重复可能会发生。
* QOS2： “只有一次”，确保消息到达一次。这一级别可用于如下情况，在计费系统中，消息重复或丢失会导致不正确的结果，资源开销大
*/
qos[i] = 1;
}
System.out.println("--设置消息发布质量");
return qos;
}
/**
* 装载各种实例和订阅主题 --- 4 ---
*/
public void create(MqttConnectOptions options, String[] topic, int[] qos) {
try {
client.setCallback(new MqttConsumerCallback(client, options, topic, qos));
System.out.println("--添加回调处理类");
client.connect(options);
} catch (Exception e) {
System.out.println("装载实例或订阅主题异常：" + e);
}
}
/**
* 订阅某个主题
*
* @param topic
* @param qos
*/
public static void subscribe(String topic, int qos) {
try {
System.out.println("topic:" + topic);
client.subscribe(topic, qos);
} catch (MqttException e) {
e.printStackTrace();
}
}
/**
* 发布，非持久化
*
* qos根据文档设置为1
*
* @param topic
* @param msg
*/
public static void publish(String topic, String msg) {
publish(1, false, topic, msg);
}
/**
* 发布
*/
public static 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 = client.getTopic(topic);
if (null == mTopic) {
System.out.println("topic：" + topic + " 不存在");
}
MqttDeliveryToken token;
try {
token = mTopic.publish(message);
token.waitForCompletion();
if (!token.isComplete()) {
System.out.println("消息发送成功");
}
} catch (MqttPersistenceException e) {
e.printStackTrace();
} catch (MqttException e) {
e.printStackTrace();
}
}
}
5、mqtt回调处理类
package com.projuct.junlaishun.mqtt;
import org.eclipse.paho.client.mqttv3.*;
import java.util.Arrays;
/**
* mqtt回调处理类
*/
public class MqttConsumerCallback implements MqttCallbackExtended {
private MqttClient client;
private MqttConnectOptions options;
private String[] topic;
private int[] qos;
public MqttConsumerCallback(MqttClient client, MqttConnectOptions options, String[] topic, int[] qos) {
this.client = client;
this.options = options;
this.topic = topic;
this.qos = qos;
}
/**
* 断开重连
*/
@Override
public void connectionLost(Throwable cause) {
System.out.println("MQTT连接断开，发起重连......");
try {
if (null != client && !client.isConnected()) {
client.reconnect();
System.out.println("尝试重新连接");
} else {
client.connect(options);
System.out.println("尝试建立新连接");
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 接收到消息调用令牌中调用
*/
@Override
public void deliveryComplete(IMqttDeliveryToken token) {
System.out.println("deliveryComplete---------" + Arrays.toString(topic));
}
/**
* 消息处理
*/
@Override
public void messageArrived(String topic, MqttMessage message) {
try {
String msg = new String(message.getPayload());
System.out.println("收到topic:" + topic + " 消息：" + msg);
System.out.println("收到消息后执行具体的业务逻辑操作，比如将消息存储进数据库");
} catch (Exception e) {
System.out.println("处理mqtt消息异常:" + e);
}
}
/**
* mqtt连接后订阅主题
*/
@Override
public void connectComplete(boolean b, String s) {
try {
if (null != topic && null != qos) {
if (client.isConnected()) {
client.subscribe(topic, qos);
System.out.println("mqtt连接成功，客户端ID：" + PropertiesUtil.MQTT_CLIENT_ID);
System.out.println("--订阅主题:：" + Arrays.toString(topic));
} else {
System.out.println("mqtt连接失败，客户端ID：" + PropertiesUtil.MQTT_CLIENT_ID);
}
}
} catch (Exception e) {
System.out.println("mqtt订阅主题异常:" + e);
}
}
}
6、编写测试方法MqttController
package com.projuct.junlaishun.mqtt;
import com.alibaba.fastjson.JSONObject;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/mqtt")
public class MqttController {
/**
* 推送消息
*/
@ResponseBody
//@GetMapping(value = "/push")
@RequestMapping("sendMqttMessage")
public JSONObject push(String topic,
String message) {
MqttConsumer.publish(topic, message);
JSONObject res = new JSONObject();
res.put("code",0);
res.put("msg","测试发布主题成功");
return res;
}
}
测试记录截图
