openfire ping的smack解决方案（维持在线状态）

连接中关联如下：

             // iq提供者
roviderManager.getInstance().addIQProvider("ping", "urn:xmpp:ping",
    new PingIQProvider());
onnection.addPacketListener(new PacketListener() {

@Override
public void processPacket(Packet p) {
    PingIQ pingIQ = (PingIQ) p;
    IQ pongIQ = pingIQ.createResultIQ(pingIQ);
    // 返回
    connection.sendPacket(pongIQ);

}
, new PacketTypeFilter(PingIQ.class));

两个关联类，PingIQ，PingIQProvider

import org.jivesoftware.smack.packet.IQ;

public class PingIQ extends IQ {

    public static final String ELEMENT = "ping";
    public static final String NAMESPACE = "urn:xmpp:ping";

    @Override
    public String getChildElementXML() {
        StringBuffer sb = new StringBuffer();
        sb.append("<").append(ELEMENT).append(" xmlns="").append(NAMESPACE)
                .append("">");

        sb.append("</").append(ELEMENT).append(">");
        return sb.toString();

    }

}

import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.provider.IQProvider;
import org.xmlpull.v1.XmlPullParser;

public class PingIQProvider implements IQProvider {

    @Override
    public IQ parseIQ(XmlPullParser parser) throws Exception {
        // TODO Auto-generated method stub
        PingIQ iq = new PingIQ();
        return iq;
    }

}

报文如下： 

<iq xmlns="jabber:client" type="get" id="65dfds" from="localhost" to="test001@xmpp.qxun.org/test"><ping xmlns="urn:xmpp:ping"/></iq>


<iq type="result" to="localhost" id="65dfds"/>