java - MQTT Android Studio 和 Raspberry PI 代理

Question

我正在学习 MQTT 和 Android Studio。我想在 Android Studio 中制作一个简单的应用程序，但我已经奋斗了 4 天，无法应对。

应用说明:1 按钮 ---> 按下 ---> 发送到 mqtt 主题/消息 ( "mqtt"/"test")仅此而已。

Mqtt Broker = rpi (IP: namerpibrok.ddns.net ) 

经纪商工作正常，不需要密码或用户名

问题出在应用程序上 - 这是我第一次使用 Android Studio 进行工作。

我按照页面上的描述做了一切:https://www.hivemq.com/blog/mqtt-client-library-enyclopedia-paho-android-service

现在，当我按下按钮时......什么也没有发生。

    MqttAndroidClient client;

    private static final String TAG = "LOG";

    // Used to load the 'native-lib' library on application startup.
static {
    System.loadLibrary("native-lib");
}

    private Object bytes;

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


    String clientId = MqttClient.generateClientId();
    client = new MqttAndroidClient(this.getApplicationContext(), "rpidomwroled.ddns.net:1883", clientId);

        MqttConnectOptions options = new MqttConnectOptions();

    try {
        IMqttToken token = client.connect(options);
        token.setActionCallback(new IMqttActionListener() {
            @Override
            public void onSuccess(IMqttToken asyncActionToken) {
                // We are connected
                                    Toast.makeText(MainActivity.this,"Połączono", Toast.LENGTH_LONG).show();

            }

            @Override
            public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                // Something went wrong e.g. connection timeout or firewall problems
                Toast.makeText(MainActivity.this,"Połączono", Toast.LENGTH_LONG).show();

            }
        });
    } catch (MqttException e) {
        e.printStackTrace();
    }
}



    MqttAndroidClient client;

    private static final String TAG = "LOG";

    // Used to load the 'native-lib' library on application startup.
static {
    System.loadLibrary("native-lib");
}

    private Object bytes;

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


    String clientId = MqttClient.generateClientId();
    client = new MqttAndroidClient(this.getApplicationContext(), "rpidomwroled.ddns.net:1883", clientId);

        MqttConnectOptions options = new MqttConnectOptions();

    try {
        IMqttToken token = client.connect(options);
        token.setActionCallback(new IMqttActionListener() {
            @Override
            public void onSuccess(IMqttToken asyncActionToken) {
                // We are connected
                                    Toast.makeText(MainActivity.this,"Połączono", Toast.LENGTH_LONG).show();

            }

            @Override
            public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                // Something went wrong e.g. connection timeout or firewall problems
                Toast.makeText(MainActivity.this,"Połączono", Toast.LENGTH_LONG).show();

            }
        });
    } catch (MqttException e) {
        e.printStackTrace();
    }
}

public void pub(View v)
{
    String topic = "mqtt";
    String payload = "mqtt";
    byte[] encodedPayload = new byte[0];
    try {
        encodedPayload = payload.getBytes("UTF-8");
        MqttMessage message = new MqttMessage(encodedPayload);
        client.publish(topic, message);
    } catch (UnsupportedEncodingException | MqttException e) {
        e.printStackTrace();
    }
    }

    }

谁能告诉我我做错了什么？

Answer 1

这段代码对我有用

String topic = "mqtt";
MqttMessage message = new MqttMessage();
message.setPayload("Message from IoT dev".getBytes());
client.publish(topic, message);

您可以通过以下方式获得回电

client.setCallback(new IoTCallbacks() {
                @Override
                public void connectionLost(Throwable cause) {

                }

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

                }

                @Override
                public void deliveryComplete(IMqttDeliveryToken token) {

                }
            });