View source for MQTT: Android Client Simple

'''PROBLEM:''' class startMqtt();


==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 = "ITTSMQTTWildan"
 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' 
 }


==main_activity.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">
 
     <TextView
         android:id="@+id/dataReceived"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintRight_toRightOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>



==Package helpers==

 package itts.onno.ittsmqttwildan.helpers;
 
 import android.content.Context;
 import android.util.Log;
 
 import org.eclipse.paho.android.service.MqttAndroidClient;
 import org.eclipse.paho.client.mqttv3.DisconnectedBufferOptions;
 import org.eclipse.paho.client.mqttv3.IMqttActionListener;
 import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
 import org.eclipse.paho.client.mqttv3.IMqttToken;
 import org.eclipse.paho.client.mqttv3.MqttCallbackExtended;
 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
 import org.eclipse.paho.client.mqttv3.MqttException;
 import org.eclipse.paho.client.mqttv3.MqttMessage;
 
 public class MqttHelper {
     public MqttAndroidClient mqttAndroidClient;
 
     final String serverUri = "tcp://192.168.0.111:1883";
 
     final String clientId = "ExampleAndroidClient";
     final String subscriptionTopic = "event";
 
     final String username = "test";
     final String password = "123456";
 
     public MqttHelper(Context context) {
         mqttAndroidClient = new MqttAndroidClient(context, serverUri, clientId);
         mqttAndroidClient.setCallback(new MqttCallbackExtended() {
             @Override
             public void connectComplete(boolean b, String s) {
                 Log.w("mqtt", s);
             }
 
             @Override
             public void connectionLost(Throwable throwable) { 
             }
 
             @Override
             public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {
                 Log.w("Mqtt", mqttMessage.toString());
             }
 
             @Override
             public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
             }
         });
         connect();
     }
 
     public void setCallback(MqttCallbackExtended callback) {
         mqttAndroidClient.setCallback(callback);
     }
 
     private void connect(){
         MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
         mqttConnectOptions.setAutomaticReconnect(true);
         mqttConnectOptions.setCleanSession(false);
         mqttConnectOptions.setUserName(username);
         mqttConnectOptions.setPassword(password.toCharArray());  
 
         try {
 
             mqttAndroidClient.connect(mqttConnectOptions, null, new IMqttActionListener() {
                 @Override
                 public void onSuccess(IMqttToken asyncActionToken) {
 
                     DisconnectedBufferOptions disconnectedBufferOptions = new DisconnectedBufferOptions();
                     disconnectedBufferOptions.setBufferEnabled(true);
                     disconnectedBufferOptions.setBufferSize(100);
                     disconnectedBufferOptions.setPersistBuffer(false);
                     disconnectedBufferOptions.setDeleteOldestMessages(false);
                     mqttAndroidClient.setBufferOpts(disconnectedBufferOptions);
                     subscribeToTopic();
                 }
 
                 @Override
                 public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                     Log.w("Mqtt", "Failed to connect to: " + serverUri + exception.toString());
                 }
             });
 
         } catch (MqttException ex){
             ex.printStackTrace();
         }
     }
 
     private void subscribeToTopic() {
         try {
             mqttAndroidClient.subscribe(subscriptionTopic, 0, null, new IMqttActionListener() {
                 @Override
                 public void onSuccess(IMqttToken asyncActionToken) {
                     Log.w("Mqtt","Subscribed!");
                 }
  
                 @Override
                 public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                     Log.w("Mqtt", "Subscribed fail!");
                 }
             });
 
         } catch (MqttException ex) {
             System.err.println("Exception whilst subscribing");
             ex.printStackTrace();
         }
     }
 
 
 }



==MainActivity.java==


 package itts.onno.ittsmqttwildan;
 
 import androidx.appcompat.app.AppCompatActivity; 
 
 import android.os.Bundle;
 import android.util.Log;
 import android.widget.TextView;
 
 import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
 import org.eclipse.paho.client.mqttv3.MqttCallbackExtended;
 import org.eclipse.paho.client.mqttv3.MqttMessage;
 
 import itts.onno.ittsmqttwildan.helpers.MqttHelper;
 
 public class MainActivity extends AppCompatActivity {
 
     MqttHelper mqttHelper;
     TextView dataReceived;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main); 
 
         dataReceived = (TextView) findViewById(R.id.dataReceived);
 
         // ------- problem & crashing-------------
         // startMqtt();
     }
 
     private void startMqtt(){
         mqttHelper = new MqttHelper(getApplicationContext());
         mqttHelper.setCallback(new MqttCallbackExtended() {
             @Override
             public void connectComplete(boolean b, String s) {
  
             }
 
             @Override
             public void connectionLost(Throwable throwable) {
 
             }
 
             @Override
             public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {
                 Log.w("Debug",mqttMessage.toString());
                 dataReceived.setText(mqttMessage.toString());
             }
 
             @Override
             public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
 
             }
          });
    }

 
 }





==Referensi==

* https://github.com/wildan2711/mqtt-android-tutorial
* https://wildanmsyah.wordpress.com/2017/05/11/mqtt-android-client-tutorial/
* https://github.com/wildan2711/mqtt-android-tutorial
* https://medium.com/swlh/android-and-mqtt-a-simple-guide-cb0cbba1931c
* https://www.eclipse.org/paho/index.php?page=clients/android/index.php