物联网mqtt协议是可以发布和订阅通过java就可以实现

话不多说,mqtt,加载pom.xml文件格式

 1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 2   <modelVersion>4.0.0</modelVersion>
 3   <groupId>com.mqtt</groupId>
 4   <artifactId>MQTTmosquitto</artifactId>
 5   <version>0.0.1-SNAPSHOT</version>
 6   <dependencies>
 7     <!-- MQTT依赖 -->
 8         <dependency>
 9             <groupId>org.eclipse.paho</groupId>
10             <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
11             <version>1.0.2</version>
12         </dependency>
13     <!-- JDBC -->
14         <dependency>
15             <groupId>mysql</groupId>
16             <artifactId>mysql-connector-java</artifactId>
17             <version>5.1.39</version>
18         </dependency>
19         
20         <!-- 阿里巴巴JSON -->
21          <dependency>
22             <groupId>com.alibaba</groupId>
23             <artifactId>fastjson</artifactId>
24             <version>1.2.28</version>
25         </dependency> 
26         
27         
28   </dependencies>
29   
30   <build>
31         <plugins>
32             <plugin>
33                 <artifactId>maven-compiler-plugin</artifactId>
34                 <version>2.3.2</version>
35                 <configuration>
36                     <source>1.8</source>
37                     <target>1.8</target>
38                 </configuration>
39             </plugin>
40             <plugin>
41                    <artifactId> maven-assembly-plugin </artifactId>
42                    <configuration>
43                         <descriptorRefs>
44                         <descriptorRef>MQTT</descriptorRef>
45                         </descriptorRefs>
46                         <archive>
47                              <manifest>
48                                   <mainClass>com.mqtt.ServerMQTT</mainClass>
49                              </manifest>
50                         </archive>
51                    </configuration>
52                    <executions>
53                         <execution>
54                              <id>make-assembly</id>
55                              <phase>package</phase>
56                              <goals>
57                                   <goal>single</goal>
58                              </goals>
59                         </execution>
60                    </executions>
61               </plugin>
62         </plugins>
63     </build>
64     
65 </project>

 

这块是发布信息代码

 1 package com.mqtt;
 2 
 3 import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
 4 import org.eclipse.paho.client.mqttv3.MqttCallback;
 5 import org.eclipse.paho.client.mqttv3.MqttClient;
 6 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
 7 import org.eclipse.paho.client.mqttv3.MqttDeliveryToken;
 8 import org.eclipse.paho.client.mqttv3.MqttException;
 9 import org.eclipse.paho.client.mqttv3.MqttMessage;
10 import org.eclipse.paho.client.mqttv3.MqttPersistenceException;
11 import org.eclipse.paho.client.mqttv3.MqttTopic;
12 import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
13 
14 public class ServerMQTT {
15 
16     public static void main(String[] args) throws MqttException {
17         ServerMQTT server = new ServerMQTT();
18         
19         server.message = new MqttMessage();
20         server.message.setQos(2);
21         server.message.setRetained(true);
22         //编辑消息
23         server.message.setPayload("你的肉".getBytes());
24         server.publish(server.topic , server.message);
25         System.out.println(server.message.isRetained() + "------ratained状态");
26     }
27         
28         //MQTT安装的服务器地址和端口号
29         public static final String HOST = "tcp://localhost:1883";
30         //定义一个主题
31         public static final String TOPIC = "test";
32         //定义MQTT的ID,可以在MQTT服务配置中指定
33         private static final String clientid = "client-1";
34         
35         private MqttClient client;
36         private MqttTopic topic;
       //用户和密码
37 private String userName = "zhny"; 38 private String passWord = "zhny2020"; 39 private MqttMessage message; 40 41 /** 42 * g构造函数 43 */ 44 public ServerMQTT() throws MqttException { 45 // MemoryPersistence设置clientid的保存形式,默认为以内存保存 46 client = new MqttClient(HOST, clientid, new MemoryPersistence()); 47 connect(); 48 } 49 50 /** 51 * l连接服务器 52 */ 53 private void connect() { 54 MqttConnectOptions options = new MqttConnectOptions(); 55 options.setCleanSession(false); 56 options.setUserName(userName); 57 options.setPassword(passWord.toCharArray()); 58 // 设置超时时间 59 options.setConnectionTimeout(10); 60 // 设置会话心跳时间 61 options.setKeepAliveInterval(20); 62 try { 63 client.setCallback(new MqttCallback() { 64 public void connectionLost(Throwable cause) { 65 // 连接丢失后,一般在这里面进行重连 66 System.out.println("连接断开……(可以做重连)"); 67 } 68 69 public void deliveryComplete(IMqttDeliveryToken token) { 70 System.out.println("deliveryComplete---------" + token.isComplete()); 71 } 72 73 public void messageArrived(String topic, MqttMessage message) throws Exception { 74 // subscribe后得到的消息会执行到这里面 75 System.out.println("接收消息主题:" + topic + " 接收消息Qos:" + message.getQos() + "接收消息内容:" + new String(message.getPayload())); 76 } 77 }); 78 client.connect(options); 79 80 topic = client.getTopic(TOPIC); 81 } catch (Exception e) { 82 e.printStackTrace(); 83 } 84 } 85 86 /** 87 * t推送消息 88 */ 89 public void publish(MqttTopic topic , MqttMessage message) throws MqttPersistenceException, MqttException { 90 MqttDeliveryToken token = topic.publish(message); 91 token.waitForCompletion(); 92 System.out.println("测试成功为true失败为false " + token.isComplete()); 93 } 94 95 96 97 }

订阅接收代码

 1 package com.mqtt;
 2  
 3 import org.eclipse.paho.client.mqttv3.MqttClient;
 4 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
 5 import org.eclipse.paho.client.mqttv3.MqttException;
 6 import org.eclipse.paho.client.mqttv3.MqttTopic;
 7 import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
 8  
 9 /**
10  * MQTT工具类操作
11  *
12  */
13 public class MQTTConnect {
14  
15         
16         public static void main(String[] args) throws MqttException {
17             MQTTConnect client = new MQTTConnect();
18             client.start();
19         }
20         
21         
22         
23         
24         
25         //MQTT安装的服务器地址和端口号(本机的ip)
26         public static final String HOST = "tcp://localhost:1883";
27         //定义一个主题
28         public static final String TOPIC = "test";
29         //定义MQTT的ID,可以在MQTT服务配置中指定
30         private static final String clientid = "client-2";
31         private MqttClient client;
32         private MqttConnectOptions options;
       //用户和密码
33 private String userName = "zhny"; 34 private String passWord = "zhny2020"; 35 36 // private ScheduledExecutorService scheduler; 37 38 public void start() { 39 try { 40 // host为主机名,clientid即连接MQTT的客户端ID,一般以唯一标识符表示,MemoryPersistence设置clientid的保存形式,默认为以内存保存 41 client = new MqttClient(HOST, clientid, new MemoryPersistence()); 42 // MQTT的连接设置 43 options = new MqttConnectOptions(); 44 // 设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录,这里设置为true表示每次连接到服务器都以新的身份连接 45 options.setCleanSession(true); 46 // 设置连接的用户名 47 options.setUserName(userName); 48 // 设置连接的密码 49 options.setPassword(passWord.toCharArray()); 50 // 设置超时时间 单位为秒 51 options.setConnectionTimeout(10); 52 // 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送个消息判断客户端是否在线,但这个方法并没有重连的机制 53 options.setKeepAliveInterval(20); 54 55 // 设置回调,client.setCallback就可以调用PushCallback类中的messageArrived()方法 56 client.setCallback(new PushCallback()); 57 MqttTopic topic = client.getTopic(TOPIC); 58 59 int qos = 2; 60 61 //setWill方法,如果项目中需要知道客户端是否掉线可以调用该方法。设置最终端口的通知消息 62 //options.setWill(topic, "This is yizhu...".getBytes(), qos, true); 63 client.connect(options); 64 //订阅消息 65 int[] Qos = {qos}; 66 String[] topic1 = {TOPIC}; 67 client.subscribe(topic1, Qos); 68 69 } catch (Exception e) { 70 e.printStackTrace(); 71 } 72 } 73 74 } 75 76 77 78 79 80 81 82
 1 package com.mqtt;
 2 
 3 
 4 
 5 
 6 
 7 import java.text.SimpleDateFormat;
 8 
 9 import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
10 import org.eclipse.paho.client.mqttv3.MqttCallback;
11 import org.eclipse.paho.client.mqttv3.MqttMessage;
12 
13 import com.alibaba.fastjson.JSONObject;
14 import com.jdbc.MySQLDemo;
15 
16 
17 
18 /**
19  * 必须实现MqttCallback的接口并实现对应的相关接口方法CallBack 类将实现 MqttCallBack。 
20  * 每个客户机标识都需要一个回调实例。在此示例中,构造函数传递客户机标识以另存为实例数据。 
21  * 在回调中,将它用来标识已经启动了该回调的哪个实例。 
22  * 必须在回调类中实现三个方法: 
23  *  public void messageArrived(MqttTopic topic, MqttMessage message)接收已经预订的发布。 
24  *  public void connectionLost(Throwable cause)在断开连接时调用。 
25  *  public void deliveryComplete(MqttDeliveryToken token)) 
26  *  接收到已经发布的 QoS 1 或 QoS 2 消息的传递令牌时调用。 
27  *  由 MqttClient.connect 激活此回调。 
28  */
29 public class PushCallback implements MqttCallback{
30     
31     
32    public void connectionLost(Throwable cause) {
33        // 连接丢失后,一般在这里面进行重连
34        System.out.println("连接断开……(可以做重连)");
35    }
36    
37    
38 
39    public void deliveryComplete(IMqttDeliveryToken token) {
40        System.out.println("deliveryComplete---------" + token.isComplete());
41    }
42    
43    
44         public void messageArrived(String topic, MqttMessage message) throws Exception {
45             // subscribe后得到的消息会执行到这里面
46             System.out.println("接收消息主题:" + topic + "  接收消息Qos:" + message.getQos() + "接收消息内容:" + new String(message.getPayload()));
47             
          //特别注意一下,messageArrived这个里面不允许调用代码和写方法,如果调用就会断开连接这个是个坑,然后用我这个try{}catch{}就没有问题了,就不会再去掉线断开连接
          try { 48 JSONObject jsonObject = JSONObject.parseObject(message.toString()); 49 String equipment=jsonObject.getString("equipment"); 50 double temperature=Double.parseDouble(jsonObject.getString("temperature")); 51 double humidity=Double.parseDouble(jsonObject.getString("humidity")); 52 String datetime=jsonObject.getString("datetime"); 53 SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd hh-mm-ss"); 54 System.out.println(equipment); 55 56 MySQLDemo mysqldemo=new MySQLDemo(); 57 mysqldemo.add(equipment, temperature, humidity, datetime); 58 } catch (Exception e) { 59 e.printStackTrace(); 60 } 61 62 } 63 64 private void MqttPublisherFetch() { 65 // 66 // JSONObject jsonObject = JSONObject.parseObject(messtr); 67 // 68 // jsonObject.put("李鹏", "1111"); 69 // 70 // jsonObject.put("李12", "222"); 71 // 72 // System.out.println(jsonObject.toString()); 73 74 // System.out.println(equipment+"-------"+temperature+"---------------"+humidity+"-----------"+datetime+"-----------猪蹄---"); 75 } 76 77 78 } 79 80
特别注意一下,messageArrived这个里面不允许调用代码和写方法,如果调用就会断开连接这个是个坑,然后用我这个try{}catch{}就没有问题了,就不会再去掉线断开连接

简单的一个小maven项目集成mqtt还有个jdbc简单的也给大家粘上去

  1 package com.jdbc;
  2  
  3 import java.sql.*;
  4 
  5 import com.alibaba.fastjson.JSONObject;
  6  
  7 public class MySQLDemo {
  8  
  9     // MySQL 8.0 以下版本 - JDBC 驱动名及数据库 URL
 10     static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
 11     static final String DB_URL = "jdbc:mysql://localhost:3306/zhny?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true";
 12  
 13     // MySQL 8.0 以上版本 - JDBC 驱动名及数据库 URL
 14     //static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";  
 15     //static final String DB_URL = "jdbc:mysql://localhost:3306/RUNOOB?useSSL=false&serverTimezone=UTC";
 16  
 17  
 18     // 数据库的用户名与密码,需要根据自己的设置
 19     static final String USER = "root";
 20     static final String PASS = "root";
 21  
 22     
 23     public void select() {
 24           Connection conn = null;
 25           Statement stmt = null;
 26           try{
 27               // 注册 JDBC 驱动
 28               Class.forName(JDBC_DRIVER);
 29           
 30               // 打开链接
 31               System.out.println("连接数据库...");
 32               conn = DriverManager.getConnection(DB_URL,USER,PASS);
 33               
 34               
 35               // 执行查询
 36               System.out.println(" 实例化Statement对象...");
 37               stmt = conn.createStatement();
 38               String sql;
 39               sql = "select * from crop";
 40               ResultSet rs = stmt.executeQuery(sql);
 41               // 展开结果集数据库
 42               while(rs.next()){
 43                   // 通过字段检索
 44                   int id  = rs.getInt("id");
 45                   String name = rs.getString("crop_name");
 46       
 47                   // 输出数据
 48                   System.out.print("ID: " + id);
 49                   System.out.print(", 站点名称: " + name);
 50                   System.out.print("\n");
 51               }
 52               // 完成后关闭
 53               rs.close();
 54               stmt.close();
 55               conn.close();
 56           }catch(SQLException se){
 57               // 处理 JDBC 错误
 58               se.printStackTrace();
 59           }catch(Exception e){
 60               // 处理 Class.forName 错误
 61               e.printStackTrace();
 62           }finally{
 63               // 关闭资源
 64               try{
 65                   if(stmt!=null) stmt.close();
 66               }catch(SQLException se2){
 67               }// 什么都不做
 68               try{
 69                   if(conn!=null) conn.close();
 70               }catch(SQLException se){
 71                   se.printStackTrace();
 72               }
 73           }
 74           System.out.println("Goodbye!");
 75     }
 76     
 77     public void add(String equipment,double temperature,double humidity,String datetime) {
 78         
 79         
 80         Connection conn = null;
 81         Statement stmt = null;
 82         try{
 83             // 注册 JDBC 驱动
 84             Class.forName(JDBC_DRIVER);
 85         
 86             // 打开链接
 87             System.out.println("连接数据库...");
 88             conn = DriverManager.getConnection(DB_URL,USER,PASS);
 89             
 90             
 91             // 执行查询
 92             System.out.println(" 实例化Statement对象...");
 93             stmt = conn.createStatement();
 94             String sql = "INSERT INTO sensor (model,device_id,temperature,humidity,date_time,section_id)\r\n" + 
 95                     "VALUES('"+equipment+"','"+temperature+"','"+temperature+"','"+humidity+"','"+datetime+"',12)";//传感器
 96             int rs = stmt.executeUpdate(sql);
 97             if (rs>0) {
 98                  System.out.println("true"+rs);
 99             }else {
100                  System.out.println("flase"+rs);
101             }
102            
103             
104             
105             stmt.close();
106             conn.close();
107         }catch(SQLException se){
108             // 处理 JDBC 错误
109             se.printStackTrace();
110         }catch(Exception e){
111             // 处理 Class.forName 错误
112             e.printStackTrace();
113         }finally{
114             // 关闭资源
115             try{
116                 if(stmt!=null) stmt.close();
117             }catch(SQLException se2){
118             }// 什么都不做
119             try{
120                 if(conn!=null) conn.close();
121             }catch(SQLException se){
122                 se.printStackTrace();
123             }
124         }
125         System.out.println("Goodbye!");
126     }
127 }

 最后接收结果