MQTT: Android Studio MQTT Test

settings.gradle

pluginManagement {
    repositories {
        gradlePluginPortal()
        google()
        mavenCentral()
        maven {
            url "https://repo.eclipse.org/content/repositories/paho-snapshots/"
        }
    }
}
dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        google()
        mavenCentral()
        maven {
            url "https://repo.eclipse.org/content/repositories/paho-snapshots/"
        }
    }
}
rootProject.name = "MQTTTest"
include ':app'

build.gradle (:app)

.....
dependencies {
    ......
    implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.0'
    implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'
    implementation 'org.greenrobot:eventbus:3.3.1'
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btnConnect"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:layout_marginBottom="10dp"
        android:text="Connect"
        app:layout_constraintBottom_toTopOf="@+id/btnPublish"
        tools:layout_editor_absoluteX="0dp" />

    <Button
        android:id="@+id/btnPublish"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:layout_marginBottom="10dp"
        android:text="Publish"
        app:layout_constraintBottom_toTopOf="@+id/btnSubscribe"
        tools:layout_editor_absoluteX="0dp" />

    <Button
        android:id="@+id/btnSubscribe"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:layout_marginBottom="10dp"
        android:text="Subscribe"
        app:layout_constraintBottom_toTopOf="@+id/textmqttmessage"
        tools:layout_editor_absoluteX="0dp" /> 

    <TextView
        android:id="@+id/textmqttmessage"
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:text="MQTT Message"
        app:layout_constraintBottom_toTopOf="@+id/btndisConnect"
        tools:layout_editor_absoluteX="0dp" />

    <Button
        android:id="@+id/btndisConnect"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        android:layout_marginBottom="52dp"
        android:text="Disconnect"
        app:layout_constraintBottom_toBottomOf="parent"
        tools:layout_editor_absoluteX="0dp" />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package itts.onno.mqtttest;

import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.greenrobot.eventbus.Logger;
import org.greenrobot.eventbus.Subscribe;


public class MainActivity extends AppCompatActivity {

    public static final String URL = "tcp://192.168.0.7:1883";
    // private String userName = "userName";
    // private String password = "password";
    // private String clientId = "clientId";
    private String userName = "onno";
    private String password = "123456";
    private String clientId = "MQTTTest";

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

        findViewById(R.id.button1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        boolean b = MqttManager.getInstance().creatConnect(URL, userName, password, clientId);
                        // Logger.d("isConnected: " + b);
                    }
                }).start();
            }
        });

        findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        MqttManager.getInstance().publish("demo", 2, "MQTT Test percobaan demo".getBytes());
                    }
                }).start();
            }
        });

        findViewById(R.id.button3).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        MqttManager.getInstance().subscribe("demo", 2);
                    }
                }).start();
            }
        });

        findViewById(R.id.button4).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            MqttManager.getInstance().disConnect();
                        } catch (MqttException e) {
 
                        }
                    }
                }).start();

            }
        });

    }

    /**
     * Subscribe to received messages
     * The Event type here can be customized as needed, here is only a basic demonstration
     *
     * @param message
     */
    @Subscribe
    public void onEvent(MqttMessage message) {
        // Logger.d(message.toString());
        Toast.makeText(this, message.toString() ,Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onResume() {
        super.onResume();
 
    }

    @Override
    protected void onPause() {
        super.onPause();
 
    }

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

}

MqttManager.java

package itts.onno.mqtttest;

import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence;
// import org.greenrobot.eventbus.Logger;
import org.greenrobot.eventbus.Subscribe;

public class MqttManager {

    // instance
    private static MqttManager mInstance = null;

    // callback
    private MqttCallback mCallback;

    // Private instance variables
    private MqttClient client;
    private MqttConnectOptions conOpt;
    private boolean clean = true;

    private MqttManager() {
        mCallback = new MqttCallbackBus();
    }

    public static MqttManager getInstance() {
        if (null == mInstance) {
            mInstance = new MqttManager();
        }
        return mInstance;
    } 

    /**
     * Release the instance, and the resources it references
     */
    public static void release() {
        try {
            if (mInstance != null) {
                mInstance.disConnect();
                mInstance = null;
            }
        } catch (Exception e) {

        }
    }

    /**
     * Create Mqtt connection
     *
     * @param brokerUrl (tcp://xxxxxx:1883)
     * @param userName
     * @param password
     * @param clientId  clientId
     * @return
     */
    public boolean creatConnect(String brokerUrl, String userName, String password, String clientId) {
        boolean flag = false;
        String tmpDir = System.getProperty("java.io.tmpdir");
        MqttDefaultFilePersistence dataStore = new MqttDefaultFilePersistence(tmpDir);

        try {
            // Construct the connection options object that contains connection parameters
            // such as cleanSession and LWT
            conOpt = new MqttConnectOptions();
            conOpt.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3_1_1);
            conOpt.setCleanSession(clean);
            if (password != null) {
                conOpt.setPassword(password.toCharArray());
            }
            if (userName != null) {
                conOpt.setUserName(userName);
            }

            // Construct an MQTT blocking mode client
            client = new MqttClient(brokerUrl, clientId, dataStore);

            // Set this wrapper as the callback handler
            client.setCallback(mCallback);
            flag = doConnect();
        } catch (MqttException e) {
            Logger.e(e.getMessage());
        }

        return flag;
    }

    /**
     * 建立连接
     *
     * @return
    */
    public boolean doConnect() {
        boolean flag = false;
        if (client != null) {
            try {
                client.connect(conOpt);
                // Logger.d("Connected to " + client.getServerURI() + " with client ID " + client.getClientId());
                flag = true;
            } catch (Exception e) {
            }
        }
        return flag;
    }

    /**
     * Publish / send a message to an MQTT server
     *
     * @param topicName the name of the topic to publish to
     * @param qos       the quality of service to delivery the message at (0,1,2)
     * @param payload   the set of bytes to send to the MQTT server
     * @return boolean
     */
    public boolean publish(String topicName, int qos, byte[] payload) {

        boolean flag = false;

        if (client != null && client.isConnected()) {

            // Logger.d("Publishing to topic \"" + topicName + "\" qos " + qos);

            // Create and configure a message
            MqttMessage message = new MqttMessage(payload);
            message.setQos(qos);

            // Send the message to the server, control is not returned until
            // it has been delivered to the server meeting the specified
            // quality of service.
            try {
                client.publish(topicName, message);
                flag = true;
            } catch (MqttException e) {

            }

        }

        return flag;
    }

    /**
     * Subscribe to a topic on an MQTT server
     * Once subscribed this method waits for the messages to arrive from the server
     * that match the subscription. It continues listening for messages until the enter key is
     * pressed.
     *
     * @param topicName to subscribe to (can be wild carded)
     * @param qos       the maximum quality of service to receive messages at for this subscription
     * @return boolean
     */
    public boolean subscribe(String topicName, int qos) {

        boolean flag = false;

        if (client != null && client.isConnected()) {
            // Subscribe to the requested topic
            // The QoS specified is the maximum level that messages will be sent to the client at.
            // For instance if QoS 1 is specified, any messages originally published at QoS 2 will
            // be downgraded to 1 when delivering to the client but messages published at 1 and 0
            // will be received at the same level they were published at.
            // Logger.d("Subscribing to topic \"" + topicName + "\" qos " + qos);
            try {
                client.subscribe(topicName, qos);
                flag = true;
            } catch (MqttException e) {

            }
        }

        return flag;

    }

    /**
     * 取消连接
     *
     * @throws MqttException
     */
    public void disConnect() throws MqttException {
        if (client != null && client.isConnected()) {
            client.disconnect();
        }
    }





}