Remove Pong class, add NAMESPACE to Ping

The Pong class was harmful, as people could try to use it with
PacketTypeFilter, which wouldn't work, a Pong is just a plain IQ result
without child XML.

smack-extensions/src/main/java/org/jivesoftware/smackx/ping/PingManager.java

@@ -47,7 +47,6 @@ import org.jivesoftware.smack.filter.PacketTypeFilter;
 import org.jivesoftware.smack.packet.Packet;
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.ping.packet.Ping;
-import org.jivesoftware.smackx.ping.packet.Pong;
 
 /**
  * Implements the XMPP Ping as defined by XEP-0199. The XMPP Ping protocol allows one entity to
@@ -59,8 +58,6 @@ import org.jivesoftware.smackx.ping.packet.Pong;
  * @see <a href="http://www.xmpp.org/extensions/xep-0199.html">XEP-0199:XMPP Ping</a>
  */
 public class PingManager extends Manager {
-    public static final String NAMESPACE = "urn:xmpp:ping";
-
     private static final Logger LOGGER = Logger.getLogger(PingManager.class.getName());
 
     private static final Map<XMPPConnection, PingManager> INSTANCES = Collections
@@ -137,15 +134,15 @@ public class PingManager extends Manager {
         executorService = new ScheduledThreadPoolExecutor(1,
                         new PingExecutorThreadFactory(connection.getConnectionCounter()));
         ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
-        sdm.addFeature(PingManager.NAMESPACE);
+        sdm.addFeature(Ping.NAMESPACE);
         INSTANCES.put(connection, this);
 
         connection.addPacketListener(new PacketListener() {
             // Send a Pong for every Ping
             @Override
             public void processPacket(Packet packet) throws NotConnectedException {
-                Pong pong = new Pong(packet);
-                connection().sendPacket(pong);
+                Ping ping = (Ping) packet;
+                connection().sendPacket(ping.getPong());
             }
         }, PING_PACKET_FILTER);
         connection.addConnectionListener(new AbstractConnectionListener() {
@@ -213,7 +210,7 @@ public class PingManager extends Manager {
      * @throws NotConnectedException 
      */
     public boolean isPingSupported(String jid) throws NoResponseException, XMPPErrorException, NotConnectedException  {
-        return ServiceDiscoveryManager.getInstanceFor(connection()).supportsFeature(jid, PingManager.NAMESPACE);
+        return ServiceDiscoveryManager.getInstanceFor(connection()).supportsFeature(jid, Ping.NAMESPACE);
     }
 
     /**

smack-extensions/src/main/java/org/jivesoftware/smackx/ping/packet/Ping.java

@@ -17,11 +17,11 @@
 package org.jivesoftware.smackx.ping.packet;
 
 import org.jivesoftware.smack.packet.IQ;
-import org.jivesoftware.smackx.ping.PingManager;
 
 public class Ping extends IQ {
 
     public static final String ELEMENT = "ping";
+    public static final String NAMESPACE = "urn:xmpp:ping";
 
     public Ping() {
     }
@@ -33,6 +33,15 @@ public class Ping extends IQ {
 
     @Override
     public String getChildElementXML() {
-        return "<" + ELEMENT + " xmlns=\'" + PingManager.NAMESPACE + "\' />";
+        return '<' + ELEMENT + " xmlns='" + NAMESPACE + "'/>";
+    }
+
+    /**
+     * Create a XMPP Pong for this Ping
+     * 
+     * @return the Pong
+     */
+    public IQ getPong() {
+        return createResultIQ(this);
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/ping/packet/Pong.java

@@ -1,45 +0,0 @@
-/**
- *
- * Copyright 2012-2014 Florian Schmaus
- *
- * 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.ping.packet;
-
-import org.jivesoftware.smack.packet.IQ;
-import org.jivesoftware.smack.packet.Packet;
-
-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(Packet 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;
-    }
-}

smack-extensions/src/test/java/org/jivesoftware/smackx/ping/PingTest.java

@@ -191,7 +191,7 @@ public class PingTest extends InitExtensions {
     public void checkSuccessfulDiscoRequest() throws Exception {
         ThreadedDummyConnection con = new ThreadedDummyConnection();
         DiscoverInfo info = new DiscoverInfo();
-        info.addFeature(PingManager.NAMESPACE);
+        info.addFeature(Ping.NAMESPACE);
         
         //@formatter:off
         String reply = 
@@ -213,7 +213,7 @@ public class PingTest extends InitExtensions {
     public void checkUnuccessfulDiscoRequest() throws Exception {
         ThreadedDummyConnection con = new ThreadedDummyConnection();
         DiscoverInfo info = new DiscoverInfo();
-        info.addFeature(PingManager.NAMESPACE);
+        info.addFeature(Ping.NAMESPACE);
         
         //@formatter:off
         String reply =