android studio 使用MQTT协议连接onenet 注意事项和相关函数

一、注意事项：

1.添加依赖：

    implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.5'
    implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'

2.在注册表允许打开网络

3.在之间添加用于支持 MQTT（Message Queuing Telemetry Transport）通信协议的 Eclipse Paho Android 服务。

4.打开项目中的 gradle.properties 文件，并确保以下属性设置为true------更新所有的支持库到AndroidX中。

android.useAndroidX=true
android.enableJetifier=true

二、程序实现：

1.建立onenet连接

private void connectToMQTT() {
        String serverUri = "tcp://183.230.40.39:6002";
        String clientId = "设备ID";
        String username = "产品ID";
        String password = "鉴权信息";
        mqttClient = new MqttAndroidClient(this, serverUri, clientId);
        MqttConnectOptions options = new MqttConnectOptions();
        options.setUserName(username);
        options.setPassword(password.toCharArray());
        try {
            mqttClient.connect(options, null, new IMqttActionListener() {
                @Override
                public void onSuccess(IMqttToken asyncActionToken) {
                    // 连接成功（订阅主题）
                    subscribeToTopic();
                }
                @Override
                public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                    // 连接失败
                    exception.printStackTrace();
                }
            });
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

2.订阅主题

private void subscribeToTopic() {
        String topic = "data/#";
        int qos = 1;
        try {
            mqttClient.subscribe(topic, qos, null, new IMqttActionListener() {
                @Override
                public void onSuccess(IMqttToken asyncActionToken) {
                    // 订阅成功
                }
                @Override
                public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                    // 订阅失败
                    exception.printStackTrace();
                }
            });
            mqttClient.setCallback(new MqttCallback() {
                @Override
                public void connectionLost(Throwable cause) {
                    // 处理连接丢失的情况
                }
                @Override
                public void messageArrived(String topic, MqttMessage message) throws Exception {
                    // 处理收到的消息
                    String data = new String(message.getPayload());
                    if(data.indexOf("temp")!=-1)
                    {
                    }
                }
                @Override
                public void deliveryComplete(IMqttDeliveryToken token) {
                    // 处理消息发送完成的情况
                }
            });
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

3.发布消息

private void publishDataToMQTT() {
        String topic = "cmd/water";
        String payload = "flag:"+count;
        int qos = 1;
        try {
            MqttMessage message = new MqttMessage(payload.getBytes());
            message.setQos(qos);
            mqttClient.publish(topic, message);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

4.断开onenet连接

private void disconnectFromMQTT() {
        try {
            mqttClient.disconnect();
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

下面就是连接成功后的效果图