in the application that I am developing, when I touch the device screen, I connect to the server and I show a busy indicator using AsyncTask, and at this point I have no problem. but while I am connected and I press the home button "the application goes to onPause" and I bring the application again apparently "onResume" and touch the screen to reconnect to the server, I get the logCat errors below.
note: in onPause I am an urnRegister WiFi receiver and I will disconnect from the server. and logCat output shows AsyncTask callback sequence
I don’t know why I get an IllegalArgumentException, I read a few posts about it and I tested an object called a “client” and it never matters
Logcat
03-09 14:26:13.413: D/MainActivity(17065): @MQTTAsynchTask(): constructor called 03-09 14:26:13.413: D/MainActivity(17065): @MQTTAsynchTask(): client is not null 03-09 14:26:13.413: D/MainActivity(17065): @MQTTAsynchTask(): onPreExecute(). 03-09 14:26:13.422: D/MainActivity(17065): @MQTTAsynchTask(): doInBackground(). 03-09 14:26:13.433: E/AndroidRuntime(17065): FATAL EXCEPTION: pool-1-thread-1 03-09 14:26:13.433: E/AndroidRuntime(17065): Process: com.example.mqtt_designlayout_02, PID: 17065 03-09 14:26:13.433: E/AndroidRuntime(17065): java.lang.IllegalArgumentException: Invalid ClientHandle 03-09 14:26:13.433: E/AndroidRuntime(17065): at org.eclipse.paho.android.service.MqttService.getConnection(MqttService.java:552) 03-09 14:26:13.433: E/AndroidRuntime(17065): at org.eclipse.paho.android.service.MqttService.connect(MqttService.java:318) 03-09 14:26:13.433: E/AndroidRuntime(17065): at org.eclipse.paho.android.service.MqttAndroidClient.doConnect(MqttAndroidClient.java:427) 03-09 14:26:13.433: E/AndroidRuntime(17065): at org.eclipse.paho.android.service.MqttAndroidClient.access$2(MqttAndroidClient.java:417) 03-09 14:26:13.433: E/AndroidRuntime(17065): at org.eclipse.paho.android.service.MqttAndroidClient$1.run(MqttAndroidClient.java:395) 03-09 14:26:13.433: E/AndroidRuntime(17065): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 03-09 14:26:13.433: E/AndroidRuntime(17065): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 03-09 14:26:13.433: E/AndroidRuntime(17065): at java.lang.Thread.run(Thread.java:818)
Asynchtask
public MQTTAsynchTask(Context contex, MqttAndroidClient client, MqttConnectOptions opts) { // TODO Auto-generated constructor stub Log.d(TAG, "@MQTTAsynchTask(): constructor called"); this.context = contex; this.MQTTAndroidClient = client; if (client != null) { Log.d(TAG, "@MQTTAsynchTask(): client is not null"); } this.opts = opts; } @Override protected void onPreExecute() { // TODO Auto-generated method stub super.onPreExecute(); Log.d(TAG, "@MQTTAsynchTask(): onPreExecute()."); dialog = new Dialog(this.context); dialog.setCancelable(false); dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); dialog.setContentView(R.layout.progressdialog); progressBar = (ProgressBar) dialog.findViewById(R.id.progressBar1); dialog.show(); } @Override protected Void doInBackground(Void... params) { // TODO Auto-generated method stub Log.d(TAG, "@MQTTAsynchTask(): doInBackground()."); do { try { this.MQTTAndroidClient.connect(this.opts, this.context, synchCONNCallBack); } catch (MqttSecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (MqttException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { Thread.sleep(MQTT_BROKER_TIME_OUT); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } this.totalTimeOut += MQTT_BROKER_TIME_OUT; } while ( (!this.isCancelled()) && (this.MQTTAndroidClient != null) && (!this.MQTTAndroidClient.isConnected()) && (this.totalTimeOut <= (10 * MQTT_BROKER_TIME_OUT)) ); return null; }
Onpause
@Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); Log.w(TAG, "@onPause()"); this.onPauseCalled = true; if (reconnectTimerCurrentlyActive) { reconnectTimerCurrentlyActive = false; reconnectTimer.cancel(); reconnectTimer.purge(); Log.v(TAG, "reconnect timer set to 'false', and reconnectTimer is cancelled"); } if (this.MQTTAsynch != null) { Log.d(TAG, "asynchTask object was initilised"); if (this.MQTTAsynch.getStatus() == AsyncTask.Status.PENDING) { Log.d(TAG, "AsynchTask has not started yet."); boolean cancelledSuccessully = this.MQTTAsynch.cancel(true); if (cancelledSuccessully) { Log.d(TAG, "AsynchTask is cancelled successfully."); } else { Log.d(TAG, "AsynchTask failed to cancell"); } } if (this.MQTTAsynch.getStatus() == AsyncTask.Status.RUNNING) { Log.d(TAG, "AsynchTask still running doing work in the backgroung thread, and it will be intrrupted"); boolean cancelledSuccessully = this.MQTTAsynch.cancel(true); if (cancelledSuccessully) { Log.d(TAG, "AsynchTask is cancelled successfully."); } else { Log.d(TAG, "AsynchTask failed to cancell"); } } if (this.MQTTAsynch.getStatus() == AsyncTask.Status.FINISHED) { Log.d(TAG, "AsynchTask has finished its work."); } } else { Log.d(TAG, "asynchTask object was not initilised. this.MQTTAsynch == null"); } if ( (this.subActivityReturned) || (this.isConnectCalled) ) { MQTT_Disconnect_Module(); } if (MQTTPrimaryReceiverRegistered) { unregisterReceiver(MQTTPrimaryReceiver); Log.v(TAG, "BroadCastReceiver (MQTTPrimaryReceiver) unregistered"); MQTTPrimaryReceiverRegistered = false; } }