How to send custom response

Hi,
I am using Smack-3.2.2.

What I am trying to do is add and implement some features and then by using xmlns, wanting to get them.

Main.java

publicclass Main {  publicstaticvoid main(String args[]) throws Throwable   {     //create Connection and connect             System.out.println(":::Adding Feature:::");    ServiceDiscoveryManager.getInstanceFor(connection).addFeature("http://jabber.org/protocol/disco#info");    ServiceDiscoveryManager.getInstanceFor(connection).addFeature("my:test:feature");      // create listener    connection.addPacketListener(            new MyCustomPacketListener(connection), new PacketFilter()            {              publicboolean accept(Packet packet)               {                if (packet.getXmlns().equals("my:test:feature"))                 {                  returntrue;                }                returnfalse;              }            });     // main method does not terminate    while (true)     {      Thread.sleep(Long.MAX_VALUE);    } 

MyCustomPacketListener.java

publicclass MyCustomPacketListener implements PacketListener {   // some code   publicvoid processPacket(Packet packet)   {    IQ response = new IQ()     {      @Override      public String getChildElementXML()       {        returnnew StringBuilder()                .append("<query xmlns=\"my:test:feature\">")                  .append("<name>")                    .append("testApp")                  .append("</name>")                  .append("<type>")                    .append("someType")                  .append("</type>")                               .append("</query>")                .toString();      }    };        response.setTo("some@jid");    response.setType(IQ.Type.RESULT);    response.setPacketID(packet.getPacketID());    connection.sendPacket(response);  }} 

From PSI, when I send:

<iq type="get" to="some@jid" id="info-1"><query xmlns='http://jabber.org/protocol/disco#info'/></iq>

I get the correct response, which have my added feature.

<iq from="some@jid/Smack" type="result" id="info-1" to="jid@some/PSI">  <query xmlns="http://jabber.org/protocol/disco#info">    <identity category="client" type="typeName" name="someName"/>    <feature var="http://jabber.org/protocol/xhtml-im"/>    <feature var="my:test:feature"/>    <feature var="http://jabber.org/protocol/disco#info"/>  </query></iq>

But when I send:

<iq type="get" to="some@jid" id="ded3"><query xmlns='my:test:feature'/></iq>

I get this error message that:

<iq from="some@jid/Smack" type="error" id="ded3" to="some@jid/Psi1"><error type="CANCEL" code="501"><feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/></error></iq>

Please can anyone tell me, what I am doing wrong here?

Thanks.