Add automatically scheduled pings in PingManager

replaces keep-alive functionality. SMACK-537

core/src/main/java/org/jivesoftware/smack/Connection.java

@@ -30,6 +30,10 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Logger;
 
@@ -222,6 +226,8 @@ public abstract class Connection {
 
     protected XMPPInputOutputStream compressionHandler;
 
+    private final ScheduledExecutorService executorService = new ScheduledThreadPoolExecutor(2);
+
     /**
      * Create a new Connection to a XMPP server.
      * 
@@ -951,4 +957,8 @@ public abstract class Connection {
             }
         }
     }
+
+    public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
+        return executorService.schedule(command, delay, unit);
+    }
 }

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

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2012-2013 Florian Schmaus
+ * 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.
@@ -18,40 +18,51 @@ package org.jivesoftware.smackx.ping;
 
 import java.lang.ref.WeakReference;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 import java.util.WeakHashMap;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
 
 import org.jivesoftware.smack.Connection;
 import org.jivesoftware.smack.ConnectionCreationListener;
+import org.jivesoftware.smack.ConnectionListener;
 import org.jivesoftware.smack.PacketListener;
-import org.jivesoftware.smack.SmackConfiguration;
 import org.jivesoftware.smack.SmackError;
 import org.jivesoftware.smack.XMPPException;
 import org.jivesoftware.smack.filter.AndFilter;
 import org.jivesoftware.smack.filter.IQTypeFilter;
 import org.jivesoftware.smack.filter.PacketFilter;
 import org.jivesoftware.smack.filter.PacketTypeFilter;
-import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.Packet;
 import org.jivesoftware.smack.packet.IQ.Type;
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 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 
+ * Implements the XMPP Ping as defined by XEP-0199. The XMPP Ping protocol allows one entity to
- * allows one entity to 'ping' any other entity by simply sending a ping to 
+ * ping any other entity by simply sending a ping to the appropriate JID. PingManger also
- * the appropriate JID.
+ * periodically sends XMPP pings to the server every 30 minutes to avoid NAT timeouts and to test
- * <p>
+ * the connection status.
  * 
  * @author Florian Schmaus
- * @see <a href="http://www.xmpp.org/extensions/xep-0199.html">XEP-0199:XMPP
+ * @see <a href="http://www.xmpp.org/extensions/xep-0199.html">XEP-0199:XMPP Ping</a>
- *      Ping</a>
  */
 public class PingManager {
-    private static Map<Connection, PingManager> instances = Collections
+    public static final String NAMESPACE = "urn:xmpp:ping";
+
+    private static final Logger LOGGER = Logger.getLogger(PingManager.class.getName());
+
+    private static final Map<Connection, PingManager> INSTANCES = Collections
             .synchronizedMap(new WeakHashMap<Connection, PingManager>());
 
+    private static final PacketFilter PING_PACKET_FILTER = new AndFilter(
+                    new PacketTypeFilter(Ping.class), new IQTypeFilter(Type.GET));
+
     static {
         Connection.addConnectionCreationListener(new ConnectionCreationListener() {
             public void connectionCreated(Connection connection) {
@@ -60,8 +71,6 @@ public class PingManager {
         });
     }
 
-    private WeakReference<Connection> weakRefConnection;
-
     /**
      * Retrieves a {@link PingManager} for the specified {@link Connection}, creating one if it doesn't already
      * exist.
@@ -71,36 +80,80 @@ public class PingManager {
      * @return The new or existing manager.
      */
     public synchronized static PingManager getInstanceFor(Connection connection) {
-        PingManager pingManager = instances.get(connection);
+        PingManager pingManager = INSTANCES.get(connection);
-
         if (pingManager == null) {
             pingManager = new PingManager(connection);
         }
         return pingManager;
     }
 
+    private static int defaultPingInterval = 60 * 30;
+
+    /**
+     * Set the default ping interval which will be used for new connections.
+     *
+     * @param interval the interval in seconds
+     */
+    public static void setDefaultPingInterval(int interval) {
+        defaultPingInterval = interval;
+    }
+
+    private final Set<PingFailedListener> pingFailedListeners = Collections
+                    .synchronizedSet(new HashSet<PingFailedListener>());
+
+    /**
+     * The interval in seconds between pings are send to the users server.
+     */
+    private int pingInterval = defaultPingInterval;
+
+    /**
+     * The time in milliseconds the last successful ping was send to the users server.
+     */
+    private volatile long lastSuccessfulAutomaticPing = -1;
+
+    private ScheduledFuture<?> nextAutomaticPing;
+
+    /**
+     * The time in milliseconds the last manual ping as successful. 
+     */
+    private long lastSuccessfulManualPing = -1;
+
+    private WeakReference<Connection> weakRefConnection;
+
     private PingManager(Connection connection) {
         weakRefConnection = new WeakReference<Connection>(connection);
         ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
-        
+        sdm.addFeature(PingManager.NAMESPACE);
-        // The ServiceDiscoveryManager was not pre-initialized
+        INSTANCES.put(connection, this);
-        if (sdm == null)
-            sdm = ServiceDiscoveryManager.getInstanceFor(connection);
-        
-        sdm.addFeature(Ping.NAMESPACE);
-        
-        PacketFilter pingPacketFilter = new AndFilter(new PacketTypeFilter(Ping.class), new IQTypeFilter(Type.GET));
 
         connection.addPacketListener(new PacketListener() {
-            /**
+            // Send a Pong for every Ping
-             * Sends a Pong for every Ping
+            @Override
-             */
             public void processPacket(Packet packet) {
                 Connection connection = weakRefConnection.get();
-                IQ pong = IQ.createResultIQ((Ping) packet);
+                Pong pong = new Pong(packet);
                 connection.sendPacket(pong);
             }
-        }, pingPacketFilter);
+        }, PING_PACKET_FILTER);
+        connection.addConnectionListener(new ConnectionListener() {
+            @Override
+            public void connectionClosed() {
+                maybeStopPingServerTask();
+            }
+            @Override
+            public void connectionClosedOnError(Exception arg0) {
+                maybeStopPingServerTask();
+            }
+            @Override
+            public void reconnectionSuccessful() {
+                maybeSchedulePingServerTask();
+            }
+            @Override
+            public void reconnectingIn(int seconds) {}
+            @Override
+            public void reconnectionFailed(Exception e) {}
+        });
+        maybeSchedulePingServerTask();
     }
 
     /**
@@ -122,7 +175,6 @@ public class PingManager {
             connection.createPacketCollectorAndSend(ping).nextResultOrThrow();
         }
         catch (XMPPException exc) {
-            
             return (jid.equals(connection.getServiceName()) && (exc.getSmackError() != SmackError.NO_RESPONSE_FROM_SERVER));
         }
         return true;
@@ -136,7 +188,8 @@ public class PingManager {
      * @return true if a reply was received from the entity, false otherwise.
      */
     public boolean ping(String jid) {
-        return ping(jid, SmackConfiguration.getDefaultPacketReplyTimeout());
+        Connection connection = weakRefConnection.get();
+        return ping(jid, connection.getPacketReplyTimeout());
     }
 
     /**
@@ -149,7 +202,7 @@ public class PingManager {
     public boolean isPingSupported(String jid) throws XMPPException {
         Connection connection = weakRefConnection.get();
         DiscoverInfo result = ServiceDiscoveryManager.getInstanceFor(connection).discoverInfo(jid);
-        return result.containsFeature(Ping.NAMESPACE);
+        return result.containsFeature(PingManager.NAMESPACE);
     }
 
     /**
@@ -163,6 +216,132 @@ public class PingManager {
      */
     public boolean pingMyServer() {
         Connection connection = weakRefConnection.get();
-        return ping(connection.getServiceName());
+        boolean res = ping(connection.getServiceName());
+        if (!res) {
+            for (PingFailedListener l : pingFailedListeners)
+                l.pingFailed();
+        } else {
+            pongReceived();
         }
+        return res;
+    }
+
+    /**
+     * Set the interval between the server is automatic pinged. A negative value disables automatic server pings.
+     *
+     * @param pingInterval the interval between the ping
+     */
+    public void setPingInterval(int pingInterval) {
+        this.pingInterval = pingInterval;
+        maybeSchedulePingServerTask();
+    }
+
+    /**
+     * Get the current ping interval.
+     *
+     * @return the interval between pings in seconds
+     */
+    public int getPingInterval() {
+        return pingInterval;
+    }
+
+    /**
+     * Register a new PingFailedListener
+     *
+     * @param listener the listener to invoke
+     */
+    public void registerPingFailedListener(PingFailedListener listener) {
+        pingFailedListeners.add(listener);
+    }
+
+    /**
+     * Unregister a PingFailedListener
+     *
+     * @param listener the listener to remove
+     */
+    public void unregisterPingFailedListener(PingFailedListener listener) {
+        pingFailedListeners.remove(listener);
+    }
+
+    /**
+     * Returns the time of the last successful Ping with the
+     * users server. If there was no successful Ping (e.g. because this
+     * feature is disabled) -1 will be returned.
+     * 
+     * @return
+     */
+    public long getLastSuccessfulPing() {
+        return Math.max(lastSuccessfulAutomaticPing, lastSuccessfulManualPing);
+    }
+
+    /**
+     * Cancels any existing periodic ping task if there is one and schedules a new ping task if
+     * pingInterval is greater then zero.
+     */
+    private synchronized void maybeSchedulePingServerTask() {
+        maybeStopPingServerTask();
+        if (pingInterval > 0) {
+            LOGGER.fine("Scheduling ServerPingTask in " + pingInterval + " seconds");
+            Connection connection = weakRefConnection.get();
+            nextAutomaticPing = connection.schedule(pingServerRunnable, pingInterval, TimeUnit.SECONDS);
+        }
+    }
+
+    private void maybeStopPingServerTask() {
+        if (nextAutomaticPing != null) {
+            nextAutomaticPing.cancel(true);
+            nextAutomaticPing = null;
+        }
+    }
+
+    private void pongReceived() {
+        lastSuccessfulManualPing = System.currentTimeMillis();
+    }
+
+    private final Runnable pingServerRunnable = new Runnable() {
+        private static final int DELTA = 1000; // 1 seconds
+        private static final int TRIES = 3; // 3 tries
+
+        public void run() {
+            LOGGER.fine("ServerPingTask run()");
+            Connection connection = weakRefConnection.get();
+            if (connection == null) {
+                // connection has been collected by GC
+                // which means we can stop the thread by breaking the loop
+                return;
+            }
+            if (connection.isAuthenticated()) {
+                boolean res = false;
+
+                for (int i = 0; i < TRIES; i++) {
+                    if (i != 0) {
+                        try {
+                            Thread.sleep(DELTA);
+                        } catch (InterruptedException e) {
+                            // We received an interrupt
+                            // This only happens if we should stop pinging
+                            return;
+                        }
+                    }
+                    res = pingMyServer();
+                    // stop when we receive a pong back
+                    if (res) {
+                        lastSuccessfulAutomaticPing = System.currentTimeMillis();
+                        break;
+                    }
+                }
+                LOGGER.fine("ServerPingTask res=" + res);
+                if (!res) {
+                    for (PingFailedListener l : pingFailedListeners) {
+                        l.pingFailed();
+                    }
+                } else {
+                    // Ping was successful, wind-up the periodic task again
+                    maybeSchedulePingServerTask();
+                }
+            } else {
+                LOGGER.warning("ServerPingTask: Connection was not authenticated");
+            }
+        }
+    };
 }

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

@@ -14,14 +14,13 @@
  * 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.smackx.ping.PingManager;
 
 public class Ping extends IQ {
 
-    public static final String NAMESPACE = "urn:xmpp:ping";
     public static final String ELEMENT = "ping";
     
     public Ping() {
@@ -34,6 +33,6 @@ public class Ping extends IQ {
     
     @Override
     public String getChildElementXML() {
-        return "<" + ELEMENT + " xmlns=\'" + NAMESPACE + "\' />";
+        return "<" + ELEMENT + " xmlns=\'" + PingManager.NAMESPACE + "\' />";
     }
 }

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

@@ -0,0 +1,45 @@
+/**
+ *
+ * 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;
+    }
+}

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

@@ -186,7 +186,7 @@ public class PingTest {
     public void checkSuccessfulDiscoRequest() throws Exception {
         ThreadedDummyConnection con = new ThreadedDummyConnection();
         DiscoverInfo info = new DiscoverInfo();
-        info.addFeature(Ping.NAMESPACE);
+        info.addFeature(PingManager.NAMESPACE);
         
         //@formatter:off
         String reply = 
@@ -209,7 +209,7 @@ public class PingTest {
     public void checkUnuccessfulDiscoRequest() throws Exception {
         ThreadedDummyConnection con = new ThreadedDummyConnection();
         DiscoverInfo info = new DiscoverInfo();
-        info.addFeature(Ping.NAMESPACE);
+        info.addFeature(PingManager.NAMESPACE);
         
         //@formatter:off
         String reply =