Smack/source/org/jivesoftware/smackx/packet/Pong.java

/**
 * Copyright 2012 Florian Schmaus
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smackx.packet;

import org.jivesoftware.smack.packet.IQ;

public class Pong extends IQ {
    
    /**
     * Composes a Pong packet from a received ping packet. This basically swaps
     * the 'from' and 'to' attributes. And sets the IQ type to result.
     * 
     * @param ping
     */
    public Pong(Ping ping) {
        setType(IQ.Type.RESULT);
        setFrom(ping.getTo());
        setTo(ping.getFrom());
        setPacketID(ping.getPacketID());
    }
    
    /*
     * Returns the child element of the Pong reply, which is non-existent. This
     * is why we return 'null' here. See e.g. Example 11 from
     * http://xmpp.org/extensions/xep-0199.html#e2e
     */
    public String getChildElementXML() {
        return null;
    }

}