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Socket error for client ID in RSMB MQTT broker when using android

I am creating a simple MQTT client for android and I get the "Socket Error for client id" error in the RMBS console. This only happens in the client implementation for Android (I also created a Java client desktop and no problem). For the Android client, I am suing the Paho Java client libraries. Here is my code:

This is an Android client:

package com.example.mqttdroid; import org.eclipse.paho.client.mqttv3.MqttCallback; import org.eclipse.paho.client.mqttv3.MqttClient; import org.eclipse.paho.client.mqttv3.MqttDeliveryToken; import org.eclipse.paho.client.mqttv3.MqttException; import org.eclipse.paho.client.mqttv3.MqttMessage; import org.eclipse.paho.client.mqttv3.MqttTopic; import org.eclipse.paho.client.mqttv3.internal.MemoryPersistence; import android.app.Activity; import android.os.AsyncTask; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.widget.Toast; public class MQTTClient extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_mqttclient); // new BackTask().execute(); not used because (seems to be the problem) MqttConnectOptions conOpts = new MqttConnectOptions(); conOpts.setKeepAliveInterval(30); conOpts.setWill(client.getTopic("Error"), "something bad happened".getBytes(), 1, true); client.connect(conOpts); client.subscribe("/House/Kitchen/Bulb"); client.setCallback( new MqttCallback() { @Override public void connectionLost(Throwable arg0) { // TODO Auto-generated method stub } @Override public void deliveryComplete(IMqttDeliveryToken arg0) { // TODO Auto-generated method stub } @Override public void messageArrived(String arg0, MqttMessage arg1) throws Exception { // TODO Auto-generated method stub Toast.makeText(Main.this, arg0.toString(), Toast.LENGTH_SHORT).show(); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.mqttclient, menu); return true; } /*public class BackTask extends AsyncTask<Void, Void, Void>{ private MqttClient client; @Override protected Void doInBackground(Void... params) { // TODO Auto-generated method stub try { client = new MqttClient("tcp://"Ip of machine running RSMB":1883", "ANDROID1", new MemoryPersistence()); client.connect(); client.subscribe("House/Kitchen/Bulb"); } catch (MqttException e) { // TODO Auto-generated catch block Log.e("ERROR", "NOT CONNECTED"); e.printStackTrace(); } return null; } @Override protected void onPostExecute(Void result) { // TODO Auto-generated method stub super.onPostExecute(result); try { client.setCallback( new MqttCallback() { @Override public void messageArrived(MqttTopic arg0, MqttMessage arg1) throws Exception { // TODO Auto-generated method stub Toast.makeText(MQTTClient.this, arg0.toString(), Toast.LENGTH_SHORT).show(); } @Override public void deliveryComplete(MqttDeliveryToken arg0) { // TODO Auto-generated method stub } @Override public void connectionLost(Throwable arg0) { // TODO Auto-generated method stub } }); } catch (MqttException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }*/

This is the Java desktop client:

  import org.eclipse.paho.client.mqttv3.MqttCallback; import org.eclipse.paho.client.mqttv3.MqttClient; import org.eclipse.paho.client.mqttv3.MqttClientPersistence; import org.eclipse.paho.client.mqttv3.MqttConnectOptions; import org.eclipse.paho.client.mqttv3.MqttDeliveryToken; import org.eclipse.paho.client.mqttv3.MqttException; import org.eclipse.paho.client.mqttv3.MqttMessage; import org.eclipse.paho.client.mqttv3.MqttPersistenceException; import org.eclipse.paho.client.mqttv3.MqttTopic; import org.eclipse.paho.client.mqttv3.internal.MemoryPersistence; public class MQTTBaseClass { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub MqttClientPersistence persistence; try { MqttClient client = new MqttClient("tcp://localhost:1883", "PC",new MemoryPersistence()); MqttConnectOptions conOpts = new MqttConnectOptions(); conOpts.setKeepAliveInterval(30); conOpts.setWill(client.getTopic("Error"), "something bad happened".getBytes(), 1, true); client.connect(conOpts); MqttMessage msg = new MqttMessage("hello".getBytes()); msg.setQos(0); msg.setRetained(true); MqttTopic topic = client.getTopic("House/Kitchen/Bulb"); client.subscribe("House/Kitchen/Bulb"); try { client.setCallback( new MqttCallback() { @Override public void messageArrived(MqttTopic arg0, MqttMessage arg1) throws Exception { // TODO Auto-generated method stub System.out.println(arg1.toString()); } @Override public void deliveryComplete(MqttDeliveryToken arg0) { // TODO Auto-generated method stub } @Override public void connectionLost(Throwable arg0) { // TODO Auto-generated method stub } }); } catch (MqttException e) { // TODO Auto-generated catch block e.printStackTrace(); } topic.publish(msg); } catch (MqttPersistenceException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (MqttException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

Just a few notes:

I connect to my Android device via Wi-Fi and my desktop when I launch the Java Dekstop client.

Destop client for Java runs on the same machine as RSMB

The Java Desktop client creates and subscribes to the topic "Home / Kitchen / Lamp" and sends a message with the string "Hello"

The Android client also subscribes to "Home / Kitchen / Lamp" and tries to display Toast with the received message.

I added internet permission to android manifest

The Android device seems to be great for the broker, but as soon as I initialize the Java Desktop Service client (or the Paho client plug-in in Eclipse and post the message), I get the error mentioned.

I started the application using the emulator on the same computer as RSMB and I get the same error.

What could be the problem?

UPDATE:

I initially got the exception "Network on Main Thread", so I translated the connection operation into AsyncTask. Now it seems that the Android client is still connected when I post a message with the Java client (Asynctask may have been causing problems), but messageArrived () from MqttCallback () does not seem to be called.

UPDATE 2:

I managed to get it to work. Here is the code I'm using now:

 package com.example.mqttphone; *import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken; 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.MemoryPersistence; import android.app.Activity; import android.os.AsyncTask; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.widget.Toast;* public class Main extends Activity { protected static String msg; public MqttClient client; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); try { client = new MqttClient("tcp://10.1.201.27:1883", "ANDROID1", new MemoryPersistence()); MqttConnectOptions conOpts = new MqttConnectOptions(); conOpts.setKeepAliveInterval(30); conOpts.setWill(client.getTopic("Error"), "something bad happened".getBytes(), 1, true); client.setCallback( new MqttCallback() { @Override public void connectionLost(Throwable arg0) { // TODO Auto-generated method stub } @Override public void deliveryComplete(IMqttDeliveryToken arg0) { // TODO Auto-generated method stub } @Override public void messageArrived(String arg0, MqttMessage arg1) throws Exception { // TODO Auto-generated method stub Main.msg = arg1.toString(); Main.this.runOnUiThread(new Runnable() { @Override public void run() { // TODO Auto-generated method stub Toast.makeText(Main.this, msg, Toast.LENGTH_LONG).show(); } }); Log.e("MESSAGE RECEIVED", arg1.toString()); } }); client.connect(conOpts); //MqttMessage msg = new MqttMessage("ANDROID MESSAGE".getBytes()); //client.getTopic("world").publish(msg); if(client.isConnected()){ client.subscribe("/House/Kitchen/Bulb"); Toast.makeText(this, "CONNECTED", Toast.LENGTH_SHORT).show(); } } catch (MqttException e) { // TODO Auto-generated catch block Log.e("ERROR", "NOT CONNECTED"); e.printStackTrace(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } }
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Hello, I am using your code, but I cannot connect my paho client to my apollo server. I hit below the error.

  I/global(677): Default buffer size used in BufferedOutputStream constructor. It would be better to be explicit if an 8k buffer is required. E/ERROR(677): NOT CONNECTED W/System.err(677): (32109) - java.io.EOFException W/System.err(677): at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:127) W/System.err(677): at java.lang.Thread.run(Thread.java:1096) W/System.err(677): Caused by: java.io.EOFException W/System.err(677): at java.io.DataInputStream.readFully(DataInputStream.java:266) W/System.err(677): at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:63) W/System.err(677): at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:94) W/System.err(677): ... 1 more

thanks
Girish

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