Develop Reference

Connect to several Mqtt servers using paho.mqtt.android

Can this library give opportunity make connections for several servers?
https://github.com/eclipse/paho.mqtt.android
I can not figure this case out the source code
For example:
mqttAndroidClient1 = new MqttAndroidClient(getApplicationContext(), "tcp://iot.eclipse.org:1883", clientId);
mqttAndroidClient2 = new MqttAndroidClient(getApplicationContext(), "tcp://iot.blablabla.org:1883", clientId);
....
mqttAndroidClient1.connect(...)
mqttAndroidClient2.connect(...)

Ok. It's work. I tested through my locale device and this service https://iot.eclipse.org/getting-started#sandboxes.
public class MainActivity extends AppCompatActivity {
private final String TAG = this.getClass().getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
Handler mHandler = new Handler();
MqttAndroidClient mqttAndroidClient1;
MqttAndroidClient mqttAndroidClient2;
String clientId = "ExampleAndroidClient";
final String serverUri = "tcp://iot.eclipse.org:1883";
final String serverUri2 = "tcp://192.168.10.11:1883" ;
#Override
protected void onStart() {
super.onStart();
clientId = clientId + System.currentTimeMillis();
mqttAndroidClient2 = new MqttAndroidClient(getApplicationContext(), serverUri2, clientId+"2");
mqttAndroidClient2.setCallback(new MqttCallbackExtended() {
#Override
public void connectComplete(boolean reconnect, String serverURI) {
if (reconnect) {
Log.i(TAG,"Reconnected to : " + serverURI);
// Because Clean Session is true, we need to re-subscribe
subscribeToTopic2();
} else {
Log.i(TAG,"Connected to: " + serverURI);
}
}
#Override
public void connectionLost(Throwable cause) {
Log.w(TAG,"The Connection was lost.");
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.i(TAG,"Incoming message: " + new String(message.getPayload()));
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
}
});
mqttAndroidClient1 = new MqttAndroidClient(getApplicationContext(), serverUri, clientId);
mqttAndroidClient1.setCallback(new MqttCallbackExtended() {
#Override
public void connectComplete(boolean reconnect, String serverURI) {
if (reconnect) {
Log.i(TAG,"Reconnected to : " + serverURI);
// Because Clean Session is true, we need to re-subscribe
subscribeToTopic1();
} else {
Log.i(TAG,"Connected to: " + serverURI);
}
}
#Override
public void connectionLost(Throwable cause) {
Log.w(TAG,"The Connection was lost.");
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.i(TAG,"Incoming message: " + new String(message.getPayload()));
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
}
});
MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
mqttConnectOptions.setAutomaticReconnect(true);
mqttConnectOptions.setCleanSession(false);
try {
//addToHistory("Connecting to " + serverUri);
mqttAndroidClient1.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);
mqttAndroidClient1.setBufferOpts(disconnectedBufferOptions);
subscribeToTopic1();
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.e(TAG,"Failed to connect to: " + mqttAndroidClient1.getServerURI());
}
});
} catch (MqttException ex){
ex.printStackTrace();
}
try {
//addToHistory("Connecting to " + serverUri);
mqttAndroidClient2.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);
mqttAndroidClient2.setBufferOpts(disconnectedBufferOptions);
subscribeToTopic2();
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.e(TAG,"Failed to connect to: " + mqttAndroidClient2.getServerURI());
}
});
} catch (MqttException ex){
ex.printStackTrace();
}
}
#Override
protected void onStop() {
super.onStop();
}
public void subscribeToTopic1(){
String subscriptionTopic = "/uwblogs";
try {
mqttAndroidClient1.subscribe(subscriptionTopic, 0, null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.i(TAG,"Subscribed!");
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.i(TAG,"Failed to subscribe");
}
});
mqttAndroidClient1.subscribe(subscriptionTopic, 0, new IMqttMessageListener() {
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
// message Arrived!
final String str = new String(message.getPayload());
mHandler.post(new Runnable() {
#Override
public void run() {
((TextView)findViewById(R.id.textView_server1)).setText(str);
}
});
Log.i(TAG,"Message: " + topic + " : " + new String(message.getPayload()));
}
});
} catch (MqttException ex){
System.err.println("Exception whilst subscribing");
ex.printStackTrace();
}
}
public void subscribeToTopic2(){
String subscriptionTopic = "/devices/wb-adc/controls/Vin";
try {
mqttAndroidClient2.subscribe(subscriptionTopic, 0, null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.i(TAG,"Subscribed!");
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.i(TAG,"Failed to subscribe");
}
});
mqttAndroidClient2.subscribe(subscriptionTopic, 0, new IMqttMessageListener() {
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
// message Arrived!
final String str = new String(message.getPayload());
mHandler.postAtFrontOfQueue(new Runnable() {
#Override
public void run() {
((TextView)findViewById(R.id.textView_server2)).setText(str);
}
});
Log.i(TAG,"Message server2: " + topic + " : " + new String(message.getPayload()));
}
});
} catch (MqttException ex){
System.err.println("Exception whilst subscribing");
ex.printStackTrace();
}
}
}

MqttAndroidClient - onFailure

Question
Why I am able to connect to my server over my mainActivity , but not over a fragment?
Setup
Program 1 - works...
Right now, I have two programs.
The first one is called mqtt_test which includes a MainActivity, a Button and the connection-class Mqtt. So there are no fragments.
With that program I am able to connect to my Server, subscribe and receive messages.
Code of first programm
public class mqtt {
private Context context;
private String broker = "tcp://10.34.5.134:1883";
private String clientId= "DefaultName";
private MqttAndroidClient client;
private ConnectionListener connectionListener;
private static final String TAG_MQTT= "MQTT";
public mqtt(Context context)
{
this.context = context;
}
public void connect()
{
final String clientId = MqttClient.generateClientId();
//set options
MqttConnectOptions options = new MqttConnectOptions();
options.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3_1);
client =
new MqttAndroidClient(context, broker,
clientId);
try {
IMqttToken token = client.connect(options);
token.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
// We are connected
Log.d(TAG_MQTT, "onSuccess");
connectionListener.connected(true);
client.setCallback(new MqttCallback() {
#Override
public void connectionLost(Throwable cause) {
Log.d(TAG_MQTT, "connectionLost: ");
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.d(TAG_MQTT, "messageArrived: Message: " + message.toString() + " with topic: " + topic);
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
Log.d(TAG_MQTT, "deliveryComplete: ");
}
});
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
// Something went wrong e.g. connection timeout or firewall problems
Log.d(TAG_MQTT, "onFailure");
connectionListener.connected(false);
}
});
} catch (MqttException e) {
e.printStackTrace();
}
}
public void subscribe(final String topic, int qos)
{
if(client.isConnected())
{
try {
IMqttToken subToken = client.subscribe(topic, qos);
subToken.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
// The message was published
Log.d(TAG_MQTT, "onSuccess: Subscripted with topic: " + topic);
}
#Override
public void onFailure(IMqttToken asyncActionToken,
Throwable exception) {
// The subscription could not be performed, maybe the user was not
// authorized to subscribe on the specified topic e.g. using wildcards
Log.d(TAG_MQTT, "onFailure: The subscription failed");
}
});
} catch (MqttException e) {
e.printStackTrace();
}
}
}
public void publish(String topic, String payload, int qos)
{
byte[] encodedPayload = new byte[0];
try {
encodedPayload = payload.getBytes("UTF-8");
MqttMessage message = new MqttMessage(encodedPayload);
client.publish(topic, message);
Log.d(TAG_MQTT, "publish: Published message:" + payload + " to topic: " + topic);
} catch (UnsupportedEncodingException | MqttException e) {
e.printStackTrace();
Log.d(TAG_MQTT, "publish: Error");
}
}
public void setConnectionListener(ConnectionListener connectionListener) {
this.connectionListener = connectionListener;
}
}
Program 2 - doesn't work
In my second program I am using nearly the same code. However, I am using fragments for future business. In some fragments are buttons, which are calling the right method.
If I press the button, then the right method gets called, like in the first program.
But the program jumps over the async task. OnSucces or onFailure never gets called.
IMqttToken token = client.connect(null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
// connected
Log.d(TAG_CONNECTION, "onSuccess");
connectionListener.connected(true);
client.setCallback(new MqttCallback() {
#Override
public void connectionLost(Throwable cause) {
Log.d(TAG_CONNECTION, "connectionLost: ");
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.d(TAG_CONNECTION, "messageArrived: Message: " + message.toString() + " with topic: " + topic);
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
Log.d(TAG_CONNECTION, "deliveryComplete: ");
}
});
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.d(TAG_CONNECTION, "onFailure");
connectionListener.connected(false);
Log.d(TAG_CONNECTION, exception.getMessage());
}
});
Then I called the connect-method over a new thread:
#Override
public void doSmth() {
new Thread(new Runnable() {
public void run() {
// a potentially time consuming task
mqttConnection.connect();
}
}).start();
}
Finally I got an answer:
D/CONNECTION: cannot start service org.eclipse.paho.android.service.MqttService
I don't understand why this doesn't work. Maybe you have some input.
To be clear: Both programs do have the same permissions:
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
Assumption
I think, I have to use more asycTasks to solve this problem.
Input/links
It would be awesome, if you could share some links. In the best case with some examples. I only found examples wich are running in a single MainActivity.

The error
D/CONNECTION: cannot start service org.eclipse.paho.android.service.MqttService
possibly indicates that the entry
<service android:name="org.eclipse.paho.android.service.MqttService">
</service>
in AndroidManifest.xml is missing

ANDROID-MQTT :Unable to connect to server (32103)

I am trying to learn basic MQTT integration in Android. I am using a mosquitto broker to publish and subscribe messages. I am running the code on a real device and getting this exception :
Unable to connect to server (32103) - java.net.ConnectException:
failed to connect to /192.168.0.103 (port 1883) after
30000ms: isConnected failed: ECONNREFUSED
Here's my code:
public class HomeActivity extends AppCompatActivity{
private MqttAndroidClient client;
private final MemoryPersistence persistence = new MemoryPersistence();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final MqttAndroidClient mqttAndroidClient = new MqttAndroidClient(this.getApplicationContext(), "tcp://192.168.0.103:1883", "androidSampleClient", persistence);
mqttAndroidClient.setCallback(new MqttCallback() {
#Override
public void connectionLost(Throwable cause) {
System.out.println("Connection was lost!");
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
System.out.println("Message Arrived!: " + topic + ": " + new String(message.getPayload()));
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
System.out.println("Delivery Complete!");
}
});
MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
mqttConnectOptions.setCleanSession(true);
try {
mqttAndroidClient.connect(mqttConnectOptions, null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
System.out.println("Connection Success!");
try {
System.out.println("Subscribing to /test");
mqttAndroidClient.subscribe("/test", 0);
System.out.println("Subscribed to /test");
System.out.println("Publishing message..");
mqttAndroidClient.publish("/test", new MqttMessage("Hello world testing..!".getBytes()));
} catch (MqttException ex) {
}
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
System.out.println("Connection Failure!");
System.out.println("throwable: " + exception.toString());
}
});
} catch (MqttException ex) {
System.out.println(ex.toString());
}
}
}
I've tried using different ports but the error is same. Can anyone help what am i doing wrong?

As you are getting started, you need to see see how different implementations work. Take a look at my implementation. I use a separated class for MQTT specific stuff.
MqttUtil.java
public class MqttUtil {
private static final String MQTT_TOPIC = "test/topic";
private static final String MQTT_URL = "tcp://localhost:1883";
private static boolean published;
private static MqttAndroidClient client;
private static final String TAG = MqttUtil.class.getName();
public static MqttAndroidClient getClient(Context context){
if(client == null){
String clientId = MqttClient.generateClientId();
client = new MqttAndroidClient(context, MQTT_URL, clientId);
}
if(!client.isConnected())
connect();
return client;
}
private static void connect(){
MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
mqttConnectOptions.setCleanSession(true);
mqttConnectOptions.setKeepAliveInterval(30);
try{
client.connect(mqttConnectOptions, null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
Log.d(TAG, "onSuccess");
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
Log.d(TAG, "onFailure. Exception when connecting: " + exception);
}
});
}catch (Exception e) {
Log.e(TAG, "Error while connecting to Mqtt broker : " + e);
e.printStackTrace();
}
}
public static void publishMessage(final String payload){
published = false;
try {
byte[] encodedpayload = payload.getBytes();
MqttMessage message = new MqttMessage(encodedpayload);
client.publish(MQTT_TOPIC, message);
published = true;
Log.i(TAG, "message successfully published : " + payload);
} catch (Exception e) {
Log.e(TAG, "Error when publishing message : " + e);
e.printStackTrace();
}
}
public static void close(){
if(client != null) {
client.unregisterResources();
client.close();
}
}
}
And you can simply use it in your HomeActivity. Check it below:
public class HomeActivity extends AppCompatActivity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get Mqtt client singleton instance
MqttUtil.getClient(this);
// Publish a sample message
MqttUtil.publishMessage("Hello Android MQTT");
}
}
For testing purposes, use your Mosquitto sub client and see if you get the message.
Hope that helps!

try using port 8883
String clientId = MqttClient.generateClientId();
final MqttAndroidClient client =
new MqttAndroidClient(this.getApplicationContext(), "ssl://iot.eclipse.org:8883",
clientId);
try {
MqttConnectOptions options = new MqttConnectOptions();
InputStream input =
this.getApplicationContext().getAssets().open("iot.eclipse.org.bks");
options.setSocketFactory(client.getSSLSocketFactory(input, "eclipse-password"));
IMqttToken token = client.connect(options);
token.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
// We are connected
Log.d(TAG, "onSuccess");
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
// Something went wrong e.g. connection timeout or firewall problems
Log.d(TAG, "onFailure");
}
});
} catch (MqttException | IOException e) {
e.printStackTrace();
}

Android MQTT async subscribe

I just start use MQTT Paho library in my app.
How to make an asynchronous subscription to the topic? (subscription in new thread)
And then in real time to receive the data and display.
It's my code in MainActivity, in main thread:
public void mqttConnect () {
final TextView textView = (TextView) findViewById(R.id.sub_Text_View);
String clientId = MqttClient.generateClientId();
final MqttAndroidClient client = new MqttAndroidClient(this.getApplicationContext(), server, clientId);
client.setCallback(new MqttCallbackExtended() {
#Override
public void connectComplete(boolean reconnect, String serverURI) {
}
#Override
public void connectionLost(Throwable cause) {
}
#Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
Log.d("NANADEV", message.toString());
textView.setText(message.toString());
}
#Override
public void deliveryComplete(IMqttDeliveryToken token) {
}
});
MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
mqttConnectOptions.setAutomaticReconnect(true);
mqttConnectOptions.setCleanSession(false);
try {
client.connect(mqttConnectOptions, null, new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
final String topic = "testwork/value";
int qos =0;
try {
IMqttToken subToken = client.subscribe(topic, qos);
subToken.setActionCallback(new IMqttActionListener() {
#Override
public void onSuccess(IMqttToken asyncActionToken) {
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
}
});
} catch (MqttException e) {
e.printStackTrace();
}
}
#Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
}
});
} catch (MqttException e) {
e.printStackTrace();
}
Thanks!

In your oncreate
private String uniqueID;
String ip="brokerip";
String port="brokerport usaly 1883"
String broker = "tcp://" + ip + ":" + port;
uniqueID = android.provider.Settings.Secure.getString(getContentResolver(), android.provider.Settings.Secure.ANDROID_ID);
IMqttAsyncClient client= new MqttAsyncClient(broker, uniqueID, new MemoryPersistence());
mqttClient.subscribe("YOURTOPIC/", 0);
mqttClient.subscribe("YOUROTHERTOPIC", 0);
and then in your method:
public void messageArrived(String topic, MqttMessage msg) throws Exception {
Log.i("mqttarrival", "Message arrived from topic " + topic);
if (topic.equals("YOURTOPIC")) {
System.out.println(msg.toString());
}
else {
}
}

Android Autobahn request.getHttpSession() = null

Client side code:
private void startPolling() {
final String wsuri = MainAsync.WEB_SOCKET_HOST_WS+"/game";
try {
mConnection.connect(wsuri, new WebSocketHandler() {
#Override
public void onOpen() {
Log.d(TAG, "Status: Connected to " + wsuri);
int role = mAccMeth.loadId(getApplicationContext());
mConnection.sendTextMessage(String.valueOf(role));
}
#Override
public void onTextMessage(String payload) {
Log.d(TAG, "Got echo: " + payload);
}
#Override
public void onClose(int code, String reason) {
Log.d(TAG, "Connection lost.");
}
});
} catch (WebSocketException e) {
Log.d(TAG, e.toString());
}
}
Server side realisation:
#ServerEndpoint(value="/game",configurator = ServletConfig.class)
public class WebSocketPollingCoordinates {
EndpointConfig endConfig;
#OnMessage
public void receiveMessage(String message,final Session session){
HttpSession httpSession = (HttpSession) endConfig.getUserProperties().get("httpSession");
//at this line i get NullpointerException
final ServletContext sercntxt = (ServletContext)httpSession.getServletContext();
}
#OnOpen
public void onOpen(Session sn, EndpointConfig ec) {
System.out.println("onOpen");
this.endConfig = ec;
}
#OnError
public void error(Session session, Throwable t) {
t.printStackTrace();
}
And WebSocket Config class:
public class ServletConfig extends Configurator{
#Override
public void modifyHandshake(ServerEndpointConfig config, HandshakeRequest request, HandshakeResponse response) {
HttpSession httpSession = (HttpSession) request.getHttpSession();
if(httpSession==null || config==null){
if(httpSession==null)
System.out.println("httpSession==null");
if(config==null)
System.out.println("config==null");
return;
}
config.getUserProperties().put("httpSession", httpSession);
}
}
I'm always getting next out: http session == null. Where is the error? I need to get httpSession, to call void httpSession.getServletContext();