Smack error in pubsub subscribe response

Smack Smack Dev
1

Hi, this is my first post here and my english is not very good, so sorry for that
I’m working with a pubsub node, which is in authorize mode.
i make a StanzaListener on the owner of the node to authorize the subscription of users:

(i think the next code is ok, but i put it because i think it can help to understand and i dont know if this is the best way to do it)

StanzaListener myListener = new StanzaListener() {
            public void processPacket(Stanza packet) {
               for(ExtensionElement extension : packet.getExtensions())
               {
                    switch (extension.getNamespace())
                    {
                         ...
                         case "jabber:x:data":
                            Form form=Form.getFormFrom(packet);
                            if (form.getField("FORM_TYPE").getValues().get(0).equals("http://jabber.org/protocol/pubsub#subscribe_authorization"))
                            {
                                Form answer = form.createAnswerForm();
                                for (FormField field : answer.getFields())
                                {
                                    switch(field.getVariable())
                                    {
                                        case "pubsub#allow":
                                            //I know, i accept all users for know
                                            field.addValue("true");
                                            break;
                                        case "FORM_TYPE":
                                            break;
                                        default:
                                            field.addValues(form.getField(field.getVariable()).getValues());
                                    }
                                }
                                Message respuesta = new Message(packet.getFrom());
                                respuesta.setFrom(packet.getTo());
                                respuesta.setStanzaId(packet.getStanzaId());
                                respuesta.addExtension(answer.getDataFormToSend());
                                try {
                                    connection.sendStanza(respuesta);
                                } catch (SmackException.NotConnectedException ex) {
                                    Logger.getLogger(Xmpp.class.getName()).log(Level.SEVERE, null, ex);
                                }
                                break;
                             }
                             ...

The problem is that when a user try to subscribe to the node, with this code:

LeafNode node = pubsubManager.getNode("thePubsubNode");
node.addItemEventListener(new ItemPubsubListener());
node.subscribe("validUser@validServer");

it gets this message error in the console:

Connection closed with error

java.lang.ClassCastException: org.jivesoftware.smack.packet.DefaultExtensionElement cannot be cast to org.jivesoftware.smackx.pubsub.NodeExtension

at org.jivesoftware.smackx.pubsub.provider.EventProvider.createReturnExtension(Eve ntProvider.java:39)

at org.jivesoftware.smackx.pubsub.provider.EventProvider.createReturnExtension(Eve ntProvider.java:34)

at org.jivesoftware.smack.provider.EmbeddedExtensionProvider.parse(EmbeddedExtensi onProvider.java:108)

at org.jivesoftware.smack.provider.EmbeddedExtensionProvider.parse(EmbeddedExtensi onProvider.java:84)

at org.jivesoftware.smack.provider.Provider.parse(Provider.java:35)

at org.jivesoftware.smack.util.PacketParserUtils.parseExtensionElement(PacketParse rUtils.java:929)

at org.jivesoftware.smack.util.PacketParserUtils.addExtensionElement(PacketParserU tils.java:1060)

at org.jivesoftware.smack.util.PacketParserUtils.parseMessage(PacketParserUtils.ja va:287)

at org.jivesoftware.smack.util.PacketParserUtils.parseStanza(PacketParserUtils.jav a:151)

at org.jivesoftware.smack.AbstractXMPPConnection.parseAndProcessStanza(AbstractXMP PConnection.java:956)

at org.jivesoftware.smack.tcp.XMPPTCPConnection.access$500(XMPPTCPConnection.java: 140)

at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPC onnection.java:989)

at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$300(XMPPTCPCon nection.java:944)

at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnecti on.java:959)

at java.lang.Thread.run(Thread.java:745)

i dont receive the answer with the approval notification in the smack debug window, and i cant make a StanzaListener, because the error occur before

I’m using smack 4.1.4, on a 15.06 ejabberd server (draugr.de)

thanks in advance and if you need more information just tell me

2

Could you show us the stanza trace when the code in question is executed? More information how to obtain the trace can be found at https://github.com/igniterealtime/Smack/wiki/How-to-ask-for-help,-report-an-issu e-and-possible-solve-the-problem-yourself

3
  1. Subscriber - PubSub Server trace:

a) Subscriber send a subscription request

<subscribe node="testNode" jid="testSubscriber@draugr.de"/>

b) Server replies with pending

<subscription jid="testSubscriber@draugr.de" node="testNode" subscription="pending"/>
  1. Server - owner trace:

a) Server sends authorization request to node owner

PubSub subscriber request

Choose whether to approve this entity’s subscription.

  <value>http://jabber.org/protocol/pubsub#subscribe_authorization</value>

testNode

  <value>testSubscriber@draugr.de</value>

false

b) Owner approves subscription request

  <value>http://jabber.org/protocol/pubsub#subscribe_authorization</value>

testNode

  <value>testSubscriber@draugr.de</value>

true

And then, based on XEP 0060 - Publish-Subscribe, there must be a message from the server to the subscriber, with the approval notification, but the error that i mention before, appears.

Obs: the smack debuger window tell that the error occur in the subscriber user