【发布时间】：2015-05-10 16:42:31
【问题描述】：
在我正在开发的应用程序中，当我触摸设备的屏幕时，我连接到服务器并使用 AsyncTask 显示忙碌指示器，在这一步我没有 问题。但是当我连接并按下主页按钮时“应用程序进入 onPause”，我让应用程序再次可见“onResume”并触摸屏幕 要再次连接到服务器，我收到以下发布的 logCat 错误。
注意：在 onPause 中，我 urnRegister WiFi 接收器并断开与服务器的连接。 logCat 输出显示了 AsyncTask 调用回调的顺序
我不知道为什么我会收到 IllegalArgumentException，我阅读了一些关于它的帖子并测试了名为“客户端”的对象，它永远不会为空
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)
异步任务
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;
}
暂停：
@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;
}
}
【问题讨论】：
-
你找到解决办法了吗？
-
问题不是您的客户端，也不是 NullPointerException（客户端为空），错误开始于此类：MqttService，第 552 行，并在 MqttAndroidClient 上继续。我建议你检查一下
-
@rmaik。我也遇到了同样的问题，请问您找到解决方法了吗？
标签： android android-asynctask mqtt