Android Mqtt通信案例

依赖包：

implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.0'
implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'

MqttService，主要功能，连接mqtt服务器，验证用户名密码，订阅Topic，回调接收到的mqtt消息

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Binder;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

import com.geti.switchcabinet.R;
import com.geti.switchcabinet.application.App;
import com.geti.switchcabinet.constant.MqttTopics;
import com.geti.switchcabinet.mqttevent.MqttConnectEvent;
import com.geti.switchcabinet.mqttevent.MqttSubscribeEvent;
import com.geti.switchcabinet.util.SaveLogUtil;

import org.eclipse.paho.android.service.MqttAndroidClient;
import org.eclipse.paho.client.mqttv3.IMqttActionListener;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.IMqttToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.greenrobot.eventbus.EventBus;

public class MQTTService extends Service {
    public static final String TAG = MQTTService.class.getSimpleName();

    private static MqttAndroidClient client;
    private MqttConnectOptions conOpt;
    private String clientId = "androidId";//客户端标识
    private IGetMessageCallBack IGetMessageCallBack;


    @Override
    public void onCreate() {
        super.onCreate();
        SaveLogUtil.saveLog(getClass().getName(), "onCreate");
        init();
    }

    public static void publish(String topic,String msg){
        Integer qos = 0;
        Boolean retained = false;
        try {
            if (client != null){
                client.publish(topic, msg.getBytes(), qos.intValue(), retained.booleanValue());
            }
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

    private void init() {
        // 服务器地址（协议+地址+端口号）
        String uri = App.MQTT_HOST;
        client = new MqttAndroidClient(this, uri, clientId);
        // 设置MQTT监听并且接受消息
        client.setCallback(mqttCallback);

        conOpt = new MqttConnectOptions();
        // 清除缓存
        conOpt.setCleanSession(true);
        // 设置超时时间，单位：秒
        conOpt.setConnectionTimeout(10);
        // 心跳包发送间隔，单位：秒
        conOpt.setKeepAliveInterval(20);
        // 用户名
        conOpt.setUserName(App.MQTT_USER);//mqtt用户名 可以全局可以写死
        // 密码
        conOpt.setPassword(App.MQTT_PWD.toCharArray());     //mqtt用户密码，全局或者写死，将字符串转换为字符串数组
      doClientConnection();

    }


    @Override
    public void onDestroy() {
        stopSelf();
        try {
            client.disconnect();
        } catch (MqttException e) {
            e.printStackTrace();
        }
        super.onDestroy();
    }

    /** 连接MQTT服务器 */
    private void doClientConnection() {
        if (!client.isConnected() && isConnectIsNormal()) {
            try {
                client.connect(conOpt, null, iMqttActionListener);
            } catch (MqttException e) {
                e.printStackTrace();
            }
        }

    }

    // MQTT是否连接成功，订阅需要的Topic
    private IMqttActionListener iMqttActionListener = new IMqttActionListener() {

        @Override
        public void onSuccess(IMqttToken arg0) {
            SaveLogUtil.saveLog(TAG, "连接成功 ");
            try {
                // 订阅myTopic话题
                client.subscribe(MqttTopics.AllSubscribeTopics,new int[]{1,1,1,1,1},null,mqttActionListener);
                EventBus.getDefault().post(new MqttConnectEvent(true));
            } catch (MqttException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onFailure(IMqttToken arg0, Throwable arg1) {
            arg1.printStackTrace();
            EventBus.getDefault().post(new MqttConnectEvent(false));
            // 连接失败，重连
        }
    };

    // MQTT监听并且接受消息
    private MqttCallback mqttCallback = new MqttCallback() {

        @Override
        public void messageArrived(String topic, MqttMessage message) throws Exception {

            String str1 = new String(message.getPayload());
            if (IGetMessageCallBack != null){
                IGetMessageCallBack.setMessage(str1);
            }
            String str2 = topic + ";qos:" + message.getQos() + ";retained:" + message.isRetained();
            SaveLogUtil.saveLog(TAG, "==收到MQTT消息1==:" + str1+"=="+str2);
        }

        @Override
        public void deliveryComplete(IMqttDeliveryToken arg0) {

        }

        @Override
        public void connectionLost(Throwable arg0) {
            // 失去连接，重连
            EventBus.getDefault().post(new MqttConnectEvent(false));
        }
    };

    private IMqttActionListener mqttActionListener = new IMqttActionListener() {
        @Override
        public void onSuccess(IMqttToken asyncActionToken) {

        }

        @Override
        public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
            EventBus.getDefault().post(new MqttSubscribeEvent(asyncActionToken.getTopics()[0],false));
        }
    };

    /** 判断网络是否连接 */
    private boolean isConnectIsNormal() {
        ConnectivityManager connectivityManager = (ConnectivityManager) this.getApplicationContext()
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = connectivityManager.getActiveNetworkInfo();
        if (info != null && info.isAvailable()) {
            String name = info.getTypeName();
            SaveLogUtil.saveLog(TAG, "==MQTT当前网络名称==" + name);
            return true;
        } else {
            SaveLogUtil.saveLog(TAG, "==MQTT 没有可用网络==");
            return false;
        }
    }


    @Override
    public IBinder onBind(Intent intent) {
        SaveLogUtil.saveLog(getClass().getName(), "==onBind==");
        return new CustomBinder();
    }

    public void setIGetMessageCallBack(IGetMessageCallBack IGetMessageCallBack){
        this.IGetMessageCallBack = IGetMessageCallBack;
    }

    public class CustomBinder extends Binder {
        public MQTTService getService(){
            return MQTTService.this;
        }
    }
}

Mqtt消息回调，也可以用 EventBus 代替

public interface IGetMessageCallBack {
    public void setMessage(String message);
}

ServiceConnection,不用说

public class MyServiceConnection implements ServiceConnection {

    private MQTTService mqttService;
    private IGetMessageCallBack IGetMessageCallBack;

    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        mqttService = ((MQTTService.CustomBinder)iBinder).getService();
        mqttService.setIGetMessageCallBack(IGetMessageCallBack);
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }

    public MQTTService getMqttService(){
        return mqttService;
    }

    public void setIGetMessageCallBack(IGetMessageCallBack IGetMessageCallBack){
        this.IGetMessageCallBack = IGetMessageCallBack;
    }
}

Activity中初始化

1.初始化主题，好在mqttservice 初始化后直接订阅这些主题，也可以根据需要修改

2.启动连接mqtt，启动mqttservice 来连接mqtt服务器，并且订阅主题，写好回调方法，大功告成