001/**
002 *
003 * Copyright 2012-2014 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.ping.packet;
018
019import org.jivesoftware.smack.packet.IQ;
020import org.jivesoftware.smack.packet.Packet;
021
022public class Pong extends IQ {
023
024    /**
025     * Composes a Pong packet from a received ping packet. This basically swaps
026     * the 'from' and 'to' attributes. And sets the IQ type to result.
027     * 
028     * @param ping
029     */
030    public Pong(Packet ping) {
031        setType(IQ.Type.RESULT);
032        setFrom(ping.getTo());
033        setTo(ping.getFrom());
034        setPacketID(ping.getPacketID());
035    }
036
037    /**
038     * Returns the child element of the Pong reply, which is non-existent. This
039     * is why we return 'null' here. See e.g. Example 11 from
040     * http://xmpp.org/extensions/xep-0199.html#e2e
041     */
042    public String getChildElementXML() {
043        return null;
044    }
045}