完整工程链接

链接：https://pan.baidu.com/s/1ykcJHPBSKBXVMaMWKoVRvA?pwd=8888 
提取码：8888

（1）创建一个新工程

（2）添加mqtt包的依赖

implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.0'

（3）联网权限配置

<uses-permission android:name="android.permission.INTERNET" />
<!--允许程序获取网络状态-->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> `

（4）添加AliyunIoTSignUtil工具类 

将创建的工具类中的所有内容   除开第一行package   剩下全部内容替换成下面内容

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();
    }

}

（5）替换MainActivity方法

此时会出现特别多报错部分，使用 ALT+ENTER引入class即可

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.os.Handler;
import android.util.Log;

import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = MainActivity.class.getSimpleName();
    private String productKey = "";// 高级版产品key
    private String deviceName = "";//已经注册的设备id
    private String deviceSecret = "";//设备秘钥

    final int POST_DEVICE_PROPERTIES_SUCCESS = 1002;
    final int POST_DEVICE_PROPERTIES_ERROR = 1003;
    private MqttClient mqttClient = null;
    private Handler mHandler ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        findViewById(R.id.MQTT_Connect_Button).setOnClickListener((l) -> {
            new Thread(() -> initAliyunIoTClient()).start();
        });
    }


    /**
     * 使用 productKey，deviceName，deviceSecret 三元组建立IoT MQTT连接
     */
    private void initAliyunIoTClient() {

        try {
            String clientId = "androidthings" + System.currentTimeMillis();

            Map<String, String> params = new HashMap<String, String>(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.cn-shanghai.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) {
            e.printStackTrace();
            mHandler.sendEmptyMessage(POST_DEVICE_PROPERTIES_ERROR);
        }
    }

    public 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(true);
        connOpts.setCleanSession(true);

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

        mqttClient.connect(connOpts);
        Log.d(TAG, "connected " + url);
    }

}

（6）添加连接阿里云按钮 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/MQTT_Connect_Button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="连接阿里云IOT"/>

</LinearLayout>

（6）将阿里云的三元组填入到代码中即可

 

 （7）开始连接