无法使用适用于 Android 的 aSmack 库创建多用户聊天 (MUC) 房间：“packet.DefaultPacketExtension 无法转换为 packet.MUCUser”

Question

对于一个应用程序，我需要能够创建一个多用户聊天室并加入它。聊天服务器是一个 openfire 服务器。

我曾经有：

MultiUserChat chat = new MultiUserChat(connection, roomName + "@conference.localhost");
chat.join(nickname);

当房间不存在时，它会创建房间并加入。但是下一个用户不能加入。他得到一个 404，收件人不可用（404）。这表明聊天室被锁定或什么的。

然后我在文档中找到了代码并尝试了以下方法：

chat.create(nickname);

// Send an empty room configuration form which indicates that we want
// an instant room
chat.sendConfigurationForm(new Form(Form.TYPE_SUBMIT));

但是，当我尝试执行此操作时，它说它崩溃并在 logcat 中出现以下错误：

03-02 12:04:12.890: E/AndroidRuntime(20872): FATAL EXCEPTION:

 AsyncTask #3 03-02 12:04:12.890: E/AndroidRuntime(20872):

 java.lang.RuntimeException: An error occured while executing
 doInBackground() 
03-02 12:04:12.890: E/AndroidRuntime(20872): Caused
 by: java.lang.ClassCastException:

 org.jivesoftware.smack.packet.DefaultPacketExtension cannot be cast to
 org.jivesoftware.smackx.packet.MUCUser 03-02 12:04:12.890:
 E/AndroidRuntime(20872):   at
 org.jivesoftware.smackx.muc.MultiUserChat.getMUCUserExtension(MultiUserChat.java:2002)
 03-02 12:04:12.890: E/AndroidRuntime(20872):   at
 org.jivesoftware.smackx.muc.MultiUserChat.create(MultiUserChat.java:364)
 03-02 12:04:12.890: E/AndroidRuntime(20872):   at
 be.xios.crs.pivi.managers.XmppManager.createOrJoinChatGroup(XmppManager.java:116)

希望有人可以帮助我并提供一些建议。

Answer 1

编辑 04/2015：Smack 4.1（或更高版本）不再需要调用 SmackAndroid.init(Context)。事实上SmackAndroid 已经不存在了。

org.jivesoftware.smack.packet.DefaultPacketExtension cannot be cast to org.jivesoftware.smackx.packet.MUCUser 通常表明您没有初始化 aSmack 的静态代码，该代码负责为 Smack 的各种数据包（和数据包扩展）类注册 Smack 提供程序。

对于大多数 aSmack 版本，只需调用

SmackAndroid.init(Context ctx)

会成功的。

Answer 2

使用此代码..

MultiUserChat muc = new MultiUserChat(connection, "roomname@<server>");
muc.create("nickname1");

Form form = muc.getConfigurationForm();
Form submitForm = form.createAnswerForm();
for (Iterator fields = form.getFields();fields.hasNext();){
  FormField field = (FormField) fields.next();
    if(!FormField.TYPE_HIDDEN.equals(field.getType()) && field.getVariable()!= null){
        submitForm.setDefaultAnswer(field.getVariable());
    }
}               
submitForm.setAnswer("muc#roomconfig_publicroom", true);
muc.sendConfigurationForm(submitForm);
muc.join("nickname1");
}catch (Exception e) {
   e.printStackTrace();
}

还可以在使用此方法登录之前手动配置提供程序管理器

public void configure(ProviderManager pm) {

    //  Private Data Storage
    pm.addIQProvider("query","jabber:iq:private", new PrivateDataManager.PrivateDataIQProvider());

    //  Time
    try {
        pm.addIQProvider("query","jabber:iq:time", Class.forName("org.jivesoftware.smackx.packet.Time"));
    } catch (ClassNotFoundException e) {
        Log.w("TestClient", "Can't load class for org.jivesoftware.smackx.packet.Time");
    }

    //  Roster Exchange
    pm.addExtensionProvider("x","jabber:x:roster", new RosterExchangeProvider());

    //  Message Events
    pm.addExtensionProvider("x","jabber:x:event", new MessageEventProvider());

    //  Chat State
    pm.addExtensionProvider("active","http://jabber.org/protocol/chatstates", new ChatStateExtension.Provider());
    pm.addExtensionProvider("composing","http://jabber.org/protocol/chatstates", new ChatStateExtension.Provider()); 
    pm.addExtensionProvider("paused","http://jabber.org/protocol/chatstates", new ChatStateExtension.Provider());
    pm.addExtensionProvider("inactive","http://jabber.org/protocol/chatstates", new ChatStateExtension.Provider());
    pm.addExtensionProvider("gone","http://jabber.org/protocol/chatstates", new ChatStateExtension.Provider());

    //  XHTML
    pm.addExtensionProvider("html","http://jabber.org/protocol/xhtml-im", new XHTMLExtensionProvider());

    //  Group Chat Invitations
    pm.addExtensionProvider("x","jabber:x:conference", new GroupChatInvitation.Provider());

    //  Service Discovery # Items    
    pm.addIQProvider("query","http://jabber.org/protocol/disco#items", new DiscoverItemsProvider());

    //  Service Discovery # Info
    pm.addIQProvider("query","http://jabber.org/protocol/disco#info", new DiscoverInfoProvider());

    //  Data Forms
    pm.addExtensionProvider("x","jabber:x:data", new DataFormProvider());

    //  MUC User
    pm.addExtensionProvider("x","http://jabber.org/protocol/muc#user", new MUCUserProvider());

    //  MUC Admin    
    pm.addIQProvider("query","http://jabber.org/protocol/muc#admin", new MUCAdminProvider());

    //  MUC Owner    
    pm.addIQProvider("query","http://jabber.org/protocol/muc#owner", new MUCOwnerProvider());

    //  Delayed Delivery
    pm.addExtensionProvider("x","jabber:x:delay", new DelayInformationProvider());

    //  Version
    try {
        pm.addIQProvider("query","jabber:iq:version", Class.forName("org.jivesoftware.smackx.packet.Version"));
    } catch (ClassNotFoundException e) {
        //  Not sure what's happening here.
    }

    //  VCard
    pm.addIQProvider("vCard","vcard-temp", new VCardProvider());

    //  Offline Message Requests
    pm.addIQProvider("offline","http://jabber.org/protocol/offline", new OfflineMessageRequest.Provider());

    //  Offline Message Indicator
    pm.addExtensionProvider("offline","http://jabber.org/protocol/offline", new OfflineMessageInfo.Provider());

    //  Last Activity
    pm.addIQProvider("query","jabber:iq:last", new LastActivity.Provider());

    //  User Search
    pm.addIQProvider("query","jabber:iq:search", new UserSearch.Provider());

    //  SharedGroupsInfo
    pm.addIQProvider("sharedgroup","http://www.jivesoftware.org/protocol/sharedgroup", new SharedGroupsInfo.Provider());

    //  JEP-33: Extended Stanza Addressing
    pm.addExtensionProvider("addresses","http://jabber.org/protocol/address", new MultipleAddressesProvider());

    //   FileTransfer
    pm.addIQProvider("si","http://jabber.org/protocol/si", new StreamInitiationProvider());

    pm.addIQProvider("query","http://jabber.org/protocol/bytestreams", new BytestreamsProvider());

    //  Privacy
    pm.addIQProvider("query","jabber:iq:privacy", new PrivacyProvider());
    pm.addIQProvider("command", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider());
    pm.addExtensionProvider("malformed-action", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider.MalformedActionError());
    pm.addExtensionProvider("bad-locale", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider.BadLocaleError());
    pm.addExtensionProvider("bad-payload", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider.BadPayloadError());
    pm.addExtensionProvider("bad-sessionid", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider.BadSessionIDError());
    pm.addExtensionProvider("session-expired", "http://jabber.org/protocol/commands", new AdHocCommandDataProvider.SessionExpiredError());
}

只需使用-configure(ProviderManager.getInstance());调用此方法