【Android】MQTT的接入

Prepare

依赖

1 implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.0' 
2 implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'

权限

<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" />

注册Service

<service android:name=".MQTTService" />
<!--自己开启的服务,导入包,Android自带Mqtt的服务,需要注册-->
<service android:name="org.eclipse.paho.android.service.MqttService" />

Crazy Coding

public class MQTTService extends Service {

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

    private static MqttAndroidClient client;
    private MqttConnectOptions conOpt;

    private String host = "tcp://xxx";   //服务器地址
    private String userName = "xxx";   //账号
    private String passWord = " xxx";   //密码
    private static String myTopic = "topic";   //频道名
    private String clientId = "mqtt_client";   //客户端ID

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        init();
        return super.onStartCommand(intent, flags, startId);
    }
　　//发布消息 msg
    public static void publish(String msg){
        String topic = myTopic;
        Integer qos = 2;
        Boolean retained = false;
        try {
            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());

        // last will message
        boolean doConnect = true;
        String message = "{\"terminal_uid\":\"" + clientId + "\"}";
        String topic = myTopic;
        Integer qos = 2;
        Boolean retained = false;
        if ((!message.equals("")) || (!topic.equals(""))) {
            // 最后
            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() {
        try {
            client.disconnect();  //服务销毁,断开连接
        } catch (MqttException e) {
            e.printStackTrace();
        }
        super.onDestroy();
    }

    /** 连接MQTT服务器 */
    private void doClientConnection() {
        if (!client.isConnected() && isConnectIsNomarl()) {
            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,当订阅多条频道,需要遍历逐条订阅,否则有可能订阅失败
                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());
            MQTTMessage msg = new MQTTMessage(); //自定义接口
            msg.setMessage(str1);
        　　//订阅信息,接收的信息message
            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 isConnectIsNomarl() {
        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;
        }
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}