Java Question Any help with this message please ?

[dealsmonkey]

Hi All,

Just got my first library working that is a wrapper for the asmack xmpp class library.

All is working fine, connects etc.

However

I am getting this log message when I try to open a toastmessage in an event raised..

The event is working fine otherwise !

ToastMessageShow(body, False)
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
   at android.os.Handler.<init>(Handler.java:121)
   at android.widget.Toast.<init>(Toast.java:68)
   at android.widget.Toast.makeText(Toast.java:231)
   at anywheresoftware.b4a.keywords.Common.ToastMessageShow(Common.java:350)
   at com.exg.Smack.main._xmpp_packetreceived(main.java:294)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:521)
   at anywheresoftware.b4a.BA.raiseEvent2(BA.java:104)
   at anywheresoftware.b4a.BA.raiseEvent(BA.java:88)
   at nejolaSmack.nejolaSmackClass$1.processPacket(nejolaSmackClass.java:122)
   at org.jivesoftware.smack.PacketReader$ListenerWrapper.notifyListener(PacketReader.java:819)
   at org.jivesoftware.smack.PacketReader$ListenerNotification.run(PacketReader.java:799)
   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
   at java.util.concurrent.FutureTask.run(FutureTask.java:137)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
   at java.lang.Thread.run(Thread.java:1102)
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Any thoughts please ?

Thanks Neil


Edit : Next time I'll think a bit more before posting !! Just adder the looper.prepare() to my source code and now is sorted !! :sign0104:

 

[agraham]

It looks like you are trying to raise a Toast from a thread other than the main UI thread. That thread does not have a message queue which is the reason for the exception you see as without a message queue it can't pump messages. In addition only the main thread can interact with the UI and you will usually get a force close if you try. In Basic4android you can raise an event on the UI thread from a different thread if you need to by calling BA.raiseEventFromDifferentThread.

 

[dealsmonkey]

It looks like you are trying to raise a Toast from a thread other than the main UI thread. That thread does not have a message queue which is the reason for the exception you see as without a message queue it can't pump messages. In addition only the main thread can interact with the UI and you will usually get a force close if you try. In Basic4android you can raise an event on the UI thread from a different thread if you need to by calling BA.raiseEventFromDifferentThread.

Thanks for that info agraham. I thought I had it sorted, but was a little to quick !

Neil

 

[dealsmonkey]

Agraham,

Thankyou a lot for your unselfish help. I have now got this working.

:sign0188:

 

[agraham]

While writing this I see that you have got it going - I hope using raiseEventFromDifferentThread. Here's what I was going to say anyway for some background info.

Just adder the looper.prepare() to my source code and now is sorted!

I'm not entirely sure that that is the correct solution. As you were already using raiseEvent then substituting raiseEventFromDifferentThread for it would probably be safer. In fact if all you have done is add a "Looper.prepare" line to the code then I'm a bit surprised you can raise a Toast at all.

Threads with Loopers are really intended to have a message Handler with a handleMessage method and then run Looper.loop to receive and process messages. This is intended to make interthread communication easier using custom messages and Runnables.

 

[agraham]

This is a useful, if slightly superficial, introduction to Loopers and Handlers Android Guts: Intro to Loopers and Handlers

 

[dealsmonkey]

Thanks, I'll have a read.

Indeed using raiseEventFromDifferentThread has solved my problem, the app now gets the message from the server using a service module

 

[manolitoGnet]

Hi All,

Just got my first library working that is a wrapper for the asmack xmpp class library.

dealsmonkey: Is your library available to other developers?

tx!

 

[Shameem]

Smack Library

Hi

Dealsmonkey, Could you produce the Library for other users

Thanks in Advance

 

[dealsmonkey]

Hi

Dealsmonkey, Could you produce the Library for other users

Thanks in Advance

I haven't looked at this in ages as I moved to the google C2DM. I weill have another look.