ClassCastException when creating MUC room for XMPP group chat using aSmack
android, chatroom, xmpp
Solution
The Packet Providers of Smack where not registered. You get a `ClassCastException` because Smack is unable to create the correct Packet class instance for MUC. I suggest that you use a newer version of aSmack and follow the instructions in the README, which should initialize and register the Providers for you.
Problem
I am using `aSmack` for creating chat application. When i am creating `groupchat` by using this `aSmack` it gives error. this is the code am using for creating `GroupChat`. ``` MultiUserChat muc = new MultiUserChat(connection, "xyz@abc.com"); try { muc.create(u_name); Form form = muc.getConfigurationForm(); Form submitForm = form.createAnswerForm(); for (Iterator<FormField> fields = form.getFields(); fields.hasNext();) { FormField field = (FormField) fields.next(); if (!FormField.TYPE_HIDDEN.equals(field.getType()) && field.getVariable() != null) { submitForm.setDefaultAnswer(field.getVariable()); } } List<String> owners = new ArrayList<String>(); Log.i(TAG, "list of owners=====" +owners.toString()); owners.add(PmUser_name); submitForm.setAnswer("muc#roomconfig_roomowners", owners); muc.sendConfigurationForm(submitForm); } catch (XMPPException e) { e.printStackTrace(); } ``` This is the jar i am using for aSmack `asmack-2010.05.07.jar`. it supports facebook xmpp, Gtalk xmpp and my own server xmpp chat. Now i want to create group chat for my own server, but it give this error. ``` E/AndroidRuntime(31002): Caused by: java.lang.ClassCastException: org.jivesoftware.smack.packet.DefaultPacketExtension E/AndroidRuntime(31002): at org.jivesoftware.smackx.muc.MultiUserChat.getMUCUserExtension(MultiUserChat.java:2000) E/AndroidRuntime(31002): at org.jivesoftware.smackx.muc.MultiUserChat.create(MultiUserChat.java:364) ``` I have search a lot but still didn't get any idea about how to solve this. Any help would be appreciated before I pull my hair out.