Android客户端阿里云MQTT签名鉴权模式的使用

项目需要，要实现Android端消息推送，预研了极光推送、阿里云MQTT，最终选择阿里云MQTT。

具体实现步骤如下：

1、添加依赖项：

在项目根目录下的build.gradle中添加：

repositories {
    maven {
        url "https://repo.eclipse.org/content/repositories/paho-releases/"
    }
}

在app目录下的build.gradle中添加：

dependencies {
    compile 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'
    compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.1'
}

2、声明权限

在AndroidManifest.xml中添加：

<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET" />

3、开启服务

在Androidmanifest.xml中添加：

<service android:name="org.eclipse.paho.android.service.MqttService" />

4、在Android Studio中采用创建Service的方式，实现阿里云MQTT，实例采用的订阅/发布者方式，也可采用p2p方式即将topic的二级设为“p2p”，三级设为目标接收方的ClientID。Service代码如下：

public class MQTTService extends Service {

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

    private static MqttAndroidClient client;
    private MqttConnectOptions conOpt;

    private String host = "tcp://192.168.0.11:61613";
    private String userName = "admin";
    private String passWord = "password";
    private static String myTopic = "ForTest";      //要订阅的主题
    private String clientId = "androidId";//客户端标识
    private IGetMessageCallBack IGetMessageCallBack;


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

    public static void publish(String msg){
        String topic = myTopic;
        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 = 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(userName);
        // 密码
        conOpt.setPassword(passWord.toCharArray());     //将字符串转换为字符串数组

        // last will message
        boolean doConnect = true;
        String message = "{\"terminal_uid\":\"" + clientId + "\"}";
        Log.e(getClass().getName(), "message是:" + message);
        String topic = myTopic;
        Integer qos = 0;
        Boolean retained = false;
        if ((!message.equals("")) || (!topic.equals(""))) {
            // 最后的遗嘱
            // MQTT本身就是为信号不稳定的网络设计的，所以难免一些客户端会无故的和Broker断开连接。
            //当客户端连接到Broker时，可以指定LWT，Broker会定期检测客户端是否有异常。
            //当客户端异常掉线时，Broker就往连接时指定的topic里推送当时指定的LWT消息。

            try {
                conOpt.setWill(topic, message.getBytes(), qos.intValue(), retained.booleanValue());
            } catch (Exception e) {
                Log.i(TAG, "Exception Occured", e);
                doConnect = false;
                iMqttActionListener.onFailure(null, e);
            }
        }

        if (doConnect) {
            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
    private IMqttActionListener iMqttActionListener = new IMqttActionListener() {

        @Override
        public void onSuccess(IMqttToken arg0) {
            Log.i(TAG, "连接成功 ");
            try {
                // 订阅myTopic话题
                client.subscribe(myTopic,1);
            } catch (MqttException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onFailure(IMqttToken arg0, Throwable arg1) {
            arg1.printStackTrace();
            // 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();
            Log.i(TAG, "messageArrived:" + str1);
            Log.i(TAG, str2);
        }

        @Override
        public void deliveryComplete(IMqttDeliveryToken arg0) {

        }

        @Override
        public void connectionLost(Throwable arg0) {
            // 失去连接，重连
        }
    };

    /** 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();
            Log.i(TAG, "MQTT当前网络名称：" + name);
            return true;
        } else {
            Log.i(TAG, "MQTT 没有可用网络");
            return false;
        }
    }


    @Override
    public IBinder onBind(Intent intent) {
        Log.e(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;
        }
    }

    public  void toCreateNotification(String message){
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 1, new Intent(this,MQTTService.class), PendingIntent.FLAG_UPDATE_CURRENT);
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);//3、创建一个通知，属性太多，使用构造器模式

        Notification notification = builder
                .setTicker("测试标题")
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("")
                .setContentText(message)
                .setContentInfo("")
                .setContentIntent(pendingIntent)//点击后才触发的意图，“挂起的”意图
                .setAutoCancel(true)        //设置点击之后notification消失
                .build();
        NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        startForeground(0, notification);
        notificationManager.notify(0, notification);

    }
}

备注：

①通过BindService去启动服务，因此没有onStartCommand()方法

②当获取从服务器推送过来的消息时，使用回调去更新UI，方便代码的迁移

③MqttAndroidClient.publish()方法，相当于服务器发布一个消息。

回调接口如下：

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

为了实现通过回调去传递从服务器端获取的消息，需要实现一个ServiceConnection类，并通过onBind来从Service和Activity之间传递数据：

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;
    }
}

测试代码：

public class MainActivity extends AppCompatActivity implements IGetMessageCallBack {

    private TextView textView;
    private Button button;
    private MyServiceConnection serviceConnection;
    private MQTTService mqttService;

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

        textView = (TextView) findViewById(R.id.text);
        button = (Button) findViewById(R.id.button);

        serviceConnection = new MyServiceConnection();
        serviceConnection.setIGetMessageCallBack(MainActivity.this);

        Intent intent = new Intent(this, MQTTService.class);

        bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);


        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                MQTTService.publish("测试一下子");
            }
        });
    }

    @Override
    public void setMessage(String message) {
        textView.setText(message);
        mqttService = serviceConnection.getMqttService();
        mqttService.toCreateNotification(message);
    }

    @Override
    protected void onDestroy() {
        unbindService(serviceConnection);
        super.onDestroy();
    }
}