基于开源JAVA MQTT Client连接阿里云IoT-阿里云开发者社区

概述

在使用阿里云官方IoT JAVA Device SDK连接云端测试的时候，发现日志总是会打印一些莫名其妙Topic消息的订阅和发布，但是用户并没有操作这些Topic，这是因为SDK底层默认做了很多系统Topic的订阅和发布设置，且无法关闭，导致很多测试不能满足预期的测试期望。如果不希望一些系统Topic的默认订阅和发布，建议可以使用开源MQTT Client进行Topic消息的订阅和发布。

操作步骤

1、创建产品和设备

参考：阿里云物联网平台Qucik Start 创建产品和设备部分。

2、pom.xml

   <dependencies>
        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.1.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>23.0</version>
        </dependency>
    </dependencies>

3、工具类 AliyunIoTSignUtil

import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.util.Arrays;
import java.util.Map;

/**
 * AliyunIoTSignUtil
 */

public class AliyunIoTSignUtil {
    public static String sign(Map<String, String> params, String deviceSecret, String signMethod) {
        //将参数Key按字典顺序排序
        String[] sortedKeys = params.keySet().toArray(new String[] {});
        Arrays.sort(sortedKeys);

        //生成规范化请求字符串
        StringBuilder canonicalizedQueryString = new StringBuilder();
        for (String key : sortedKeys) {
            if ("sign".equalsIgnoreCase(key)) {
                continue;
            }
            canonicalizedQueryString.append(key).append(params.get(key));
        }

        try {
            String key = deviceSecret;
            return encryptHMAC(signMethod,canonicalizedQueryString.toString(), key);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * HMACSHA1加密
     *
     */
    public static String encryptHMAC(String signMethod,String content, String key) throws Exception {
        SecretKey secretKey = new SecretKeySpec(key.getBytes("utf-8"), signMethod);
        Mac mac = Mac.getInstance(secretKey.getAlgorithm());
        mac.init(secretKey);
        byte[] data = mac.doFinal(content.getBytes("utf-8"));
        return bytesToHexString(data);
    }

    public static final String bytesToHexString(byte[] bArray) {

        StringBuffer sb = new StringBuffer(bArray.length);
        String sTemp;
        for (int i = 0; i < bArray.length; i++) {
            sTemp = Integer.toHexString(0xFF & bArray[i]);
            if (sTemp.length() < 2) {
                sb.append(0);
            }
            sb.append(sTemp.toUpperCase());
        }
        return sb.toString();
    }
}

4、main方法

import com.alibaba.taro.AliyunIoTSignUtil;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import java.util.HashMap;
import java.util.Map;

public class IoTDemoPubSubDemo {

    public static String productKey = "********";
    public static String deviceName = "OpenMQTTDevice";
    public static String deviceSecret = "********";
    public static String regionId = "cn-shanghai";

    // 物模型-属性上报topic
    private static String pubTopic = "/sys/" + productKey + "/" + deviceName + "/thing/event/property/post";
    // 自定义topic，在产品Topic列表位置定义
    private static String subTopic = "/"+productKey + "/" + deviceName+"/user/newdatademo";

    private static MqttClient mqttClient;

    public static void main(String [] args){

        initAliyunIoTClient();
//        ScheduledExecutorService scheduledThreadPool = new ScheduledThreadPoolExecutor(1,
//                new ThreadFactoryBuilder().setNameFormat("thread-runner-%d").build());
//
//        scheduledThreadPool.scheduleAtFixedRate(()->postDeviceProperties(), 10,10, TimeUnit.SECONDS);
        // 汇报属性
        postDeviceProperties();
        try {
            mqttClient.subscribe(subTopic); // 订阅Topic
        } catch (MqttException e) {
            System.out.println("error:" + e.getMessage());
            e.printStackTrace();
        }

        // 设置订阅监听
        mqttClient.setCallback(new MqttCallback() {
            @Override
            public void connectionLost(Throwable throwable) {
                System.out.println("connection Lost");

            }

            @Override
            public void messageArrived(String s, MqttMessage mqttMessage) throws Exception {
                System.out.println("Sub message");
                System.out.println("Topic : " + s);
                System.out.println(new String(mqttMessage.getPayload())); //打印输出消息payLoad
            }

            @Override
            public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {

            }
        });

    }

    /**
     * 初始化 Client 对象
     */
    private static void initAliyunIoTClient() {

        try {
            // 构造连接需要的参数
            String clientId = "java" + System.currentTimeMillis();
            Map<String, String> params = new HashMap<>(16);
            params.put("productKey", productKey);
            params.put("deviceName", deviceName);
            params.put("clientId", clientId);
            String timestamp = String.valueOf(System.currentTimeMillis());
            params.put("timestamp", timestamp);
            // cn-shanghai
            String targetServer = "tcp://" + productKey + ".iot-as-mqtt."+regionId+".aliyuncs.com:1883";

            String mqttclientId = clientId + "|securemode=3,signmethod=hmacsha1,timestamp=" + timestamp + "|";
            String mqttUsername = deviceName + "&" + productKey;
            String mqttPassword = AliyunIoTSignUtil.sign(params, deviceSecret, "hmacsha1");

            connectMqtt(targetServer, mqttclientId, mqttUsername, mqttPassword);

        } catch (Exception e) {
            System.out.println("initAliyunIoTClient error " + e.getMessage());
        }
    }

    public static void connectMqtt(String url, String clientId, String mqttUsername, String mqttPassword) throws Exception {

        MemoryPersistence persistence = new MemoryPersistence();
        mqttClient = new MqttClient(url, clientId, persistence);
        MqttConnectOptions connOpts = new MqttConnectOptions();
        // MQTT 3.1.1
        connOpts.setMqttVersion(4);
        connOpts.setAutomaticReconnect(false);
        connOpts.setCleanSession(true);

        connOpts.setUserName(mqttUsername);
        connOpts.setPassword(mqttPassword.toCharArray());
        connOpts.setKeepAliveInterval(60);

        mqttClient.connect(connOpts);
    }

    /**
     * 汇报属性
     */
    private static void postDeviceProperties() {

        try {
            //上报数据
            //高级版 物模型-属性上报payload
            System.out.println("上报属性值");
            String payloadJson = "{\"params\":{\"Status\":0,\"Data\":\"15\"}}";
            MqttMessage message = new MqttMessage(payloadJson.getBytes("utf-8"));
            message.setQos(1);
            mqttClient.publish(pubTopic, message);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

5、运行测试情况

参考链接

基于开源MQTT自主接入阿里云IoT平台（Java）
MQTT-TCP连接通信