PingManager.java
/**
*
* Copyright 2012-2015 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;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.WeakHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jivesoftware.smack.AbstractConnectionClosedListener;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.NoResponseException;
import org.jivesoftware.smack.SmackException.NotConnectedException;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.ConnectionCreationListener;
import org.jivesoftware.smack.Manager;
import org.jivesoftware.smack.XMPPConnectionRegistry;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.XMPPException.XMPPErrorException;
import org.jivesoftware.smack.iqrequest.AbstractIqRequestHandler;
import org.jivesoftware.smack.iqrequest.IQRequestHandler.Mode;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.IQ.Type;
import org.jivesoftware.smack.util.SmackExecutorThreadFactory;
import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
import org.jivesoftware.smackx.ping.packet.Ping;
import org.jxmpp.jid.Jid;
/**
* Implements the XMPP Ping as defined by XEP-0199. The XMPP Ping protocol allows one entity to
* ping any other entity by simply sending a ping to the appropriate JID. PingManger also
* periodically sends XMPP pings to the server to avoid NAT timeouts and to test
* the connection status.
* <p>
* The default server ping interval is 30 minutes and can be modified with
* {@link #setDefaultPingInterval(int)} and {@link #setPingInterval(int)}.
* </p>
*
* @author Florian Schmaus
* @see <a href="http://www.xmpp.org/extensions/xep-0199.html">XEP-0199:XMPP Ping</a>
*/
public class PingManager extends Manager {
private static final Logger LOGGER = Logger.getLogger(PingManager.class.getName());
private static final Map<XMPPConnection, PingManager> INSTANCES = new WeakHashMap<XMPPConnection, PingManager>();
static {
XMPPConnectionRegistry.addConnectionCreationListener(new ConnectionCreationListener() {
public void connectionCreated(XMPPConnection connection) {
getInstanceFor(connection);
}
});
}
/**
* Retrieves a {@link PingManager} for the specified {@link XMPPConnection}, creating one if it doesn't already
* exist.
*
* @param connection
* The connection the manager is attached to.
* @return The new or existing manager.
*/
public synchronized static PingManager getInstanceFor(XMPPConnection connection) {
PingManager pingManager = INSTANCES.get(connection);
if (pingManager == null) {
pingManager = new PingManager(connection);
INSTANCES.put(connection, pingManager);
}
return pingManager;
}
/**
* The default ping interval in seconds used by new PingManager instances. The default is 30 minutes.
*/
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>());
private final ScheduledExecutorService executorService;
/**
* The interval in seconds between pings are send to the users server.
*/
private int pingInterval = defaultPingInterval;
private ScheduledFuture<?> nextAutomaticPing;
private PingManager(XMPPConnection connection) {
super(connection);
executorService = Executors.newSingleThreadScheduledExecutor(
new SmackExecutorThreadFactory(connection.getConnectionCounter(), "Ping"));
ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection);
sdm.addFeature(Ping.NAMESPACE);
connection.registerIQRequestHandler(new AbstractIqRequestHandler(Ping.ELEMENT, Ping.NAMESPACE, Type.get, Mode.async) {
@Override
public IQ handleIQRequest(IQ iqRequest) {
Ping ping = (Ping) iqRequest;
return ping.getPong();
}
});
connection.addConnectionListener(new AbstractConnectionClosedListener() {
@Override
public void authenticated(XMPPConnection connection, boolean resumed) {
maybeSchedulePingServerTask();
}
@Override
public void connectionTerminated() {
maybeStopPingServerTask();
}
});
maybeSchedulePingServerTask();
}
/**
* Pings the given jid. This method will return false if an error occurs. The exception
* to this, is a server ping, which will always return true if the server is reachable,
* event if there is an error on the ping itself (i.e. ping not supported).
* <p>
* Use {@link #isPingSupported(Jid)} to determine if XMPP Ping is supported
* by the entity.
*
* @param jid The id of the entity the ping is being sent to
* @param pingTimeout The time to wait for a reply in milliseconds
* @return true if a reply was received from the entity, false otherwise.
* @throws NoResponseException if there was no response from the jid.
* @throws NotConnectedException
* @throws InterruptedException
*/
public boolean ping(Jid jid, long pingTimeout) throws NotConnectedException, NoResponseException, InterruptedException {
final XMPPConnection connection = connection();
// Packet collector for IQs needs an connection that was at least authenticated once,
// otherwise the client JID will be null causing an NPE
if (!connection.isAuthenticated()) {
throw new NotConnectedException();
}
Ping ping = new Ping(jid);
try {
connection.createPacketCollectorAndSend(ping).nextResultOrThrow(pingTimeout);
}
catch (XMPPException exc) {
return jid.equals(connection.getServiceName());
}
return true;
}
/**
* Same as calling {@link #ping(Jid, long)} with the defaultpacket reply
* timeout.
*
* @param jid The id of the entity the ping is being sent to
* @return true if a reply was received from the entity, false otherwise.
* @throws NotConnectedException
* @throws NoResponseException if there was no response from the jid.
* @throws InterruptedException
*/
public boolean ping(Jid jid) throws NotConnectedException, NoResponseException, InterruptedException {
return ping(jid, connection().getPacketReplyTimeout());
}
/**
* Query the specified entity to see if it supports the Ping protocol (XEP-0199)
*
* @param jid The id of the entity the query is being sent to
* @return true if it supports ping, false otherwise.
* @throws XMPPErrorException An XMPP related error occurred during the request
* @throws NoResponseException if there was no response from the jid.
* @throws NotConnectedException
* @throws InterruptedException
*/
public boolean isPingSupported(Jid jid) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
return ServiceDiscoveryManager.getInstanceFor(connection()).supportsFeature(jid, Ping.NAMESPACE);
}
/**
* Pings the server. This method will return true if the server is reachable. It
* is the equivalent of calling <code>ping</code> with the XMPP domain.
* <p>
* Unlike the {@link #ping(Jid)} case, this method will return true even if
* {@link #isPingSupported(Jid)} is false.
*
* @return true if a reply was received from the server, false otherwise.
* @throws NotConnectedException
* @throws InterruptedException
*/
public boolean pingMyServer() throws NotConnectedException, InterruptedException {
return pingMyServer(true);
}
/**
* Pings the server. This method will return true if the server is reachable. It
* is the equivalent of calling <code>ping</code> with the XMPP domain.
* <p>
* Unlike the {@link #ping(Jid)} case, this method will return true even if
* {@link #isPingSupported(Jid)} is false.
*
* @param notifyListeners Notify the PingFailedListener in case of error if true
* @return true if the user's server could be pinged.
* @throws NotConnectedException
* @throws InterruptedException
*/
public boolean pingMyServer(boolean notifyListeners) throws NotConnectedException, InterruptedException {
return pingMyServer(notifyListeners, connection().getPacketReplyTimeout());
}
/**
* Pings the server. This method will return true if the server is reachable. It
* is the equivalent of calling <code>ping</code> with the XMPP domain.
* <p>
* Unlike the {@link #ping(Jid)} case, this method will return true even if
* {@link #isPingSupported(Jid)} is false.
*
* @param notifyListeners Notify the PingFailedListener in case of error if true
* @param pingTimeout The time to wait for a reply in milliseconds
* @return true if the user's server could be pinged.
* @throws NotConnectedException
* @throws InterruptedException
*/
public boolean pingMyServer(boolean notifyListeners, long pingTimeout) throws NotConnectedException, InterruptedException {
boolean res;
try {
res = ping(connection().getServiceName(), pingTimeout);
}
catch (NoResponseException e) {
res = false;
}
if (!res && notifyListeners) {
for (PingFailedListener l : pingFailedListeners)
l.pingFailed();
}
return res;
}
/**
* Set the interval in seconds between a automated server ping is send. A negative value disables automatic server
* pings. All settings take effect immediately. If there is an active scheduled server ping it will be canceled and,
* if <code>pingInterval</code> is positive, a new one will be scheduled in pingInterval seconds.
* <p>
* If the ping fails after 3 attempts waiting the connections reply timeout for an answer, then the ping failed
* listeners will be invoked.
* </p>
*
* @param pingInterval the interval in seconds between the automated server pings
*/
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);
}
private void maybeSchedulePingServerTask() {
maybeSchedulePingServerTask(0);
}
/**
* Cancels any existing periodic ping task if there is one and schedules a new ping task if
* pingInterval is greater then zero.
*
* @param delta the delta to the last received stanza in seconds
*/
private synchronized void maybeSchedulePingServerTask(int delta) {
maybeStopPingServerTask();
if (pingInterval > 0) {
int nextPingIn = pingInterval - delta;
LOGGER.fine("Scheduling ServerPingTask in " + nextPingIn + " seconds (pingInterval="
+ pingInterval + ", delta=" + delta + ")");
nextAutomaticPing = executorService.schedule(pingServerRunnable, nextPingIn, TimeUnit.SECONDS);
}
}
private void maybeStopPingServerTask() {
if (nextAutomaticPing != null) {
nextAutomaticPing.cancel(true);
nextAutomaticPing = null;
}
}
/**
* Ping the server if deemed necessary because automatic server pings are
* enabled ({@link #setPingInterval(int)}) and the ping interval has expired.
*/
public synchronized void pingServerIfNecessary() {
final int DELTA = 1000; // 1 seconds
final int TRIES = 3; // 3 tries
final XMPPConnection connection = connection();
if (connection == null) {
// connection has been collected by GC
// which means we can stop the thread by breaking the loop
return;
}
if (pingInterval <= 0) {
// Ping has been disabled
return;
}
long lastStanzaReceived = connection.getLastStanzaReceived();
if (lastStanzaReceived > 0) {
long now = System.currentTimeMillis();
// Delta since the last stanza was received
int deltaInSeconds = (int) ((now - lastStanzaReceived) / 1000);
// If the delta is small then the ping interval, then we can defer the ping
if (deltaInSeconds < pingInterval) {
maybeSchedulePingServerTask(deltaInSeconds);
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;
}
}
try {
res = pingMyServer(false);
}
catch (InterruptedException | SmackException e) {
LOGGER.log(Level.WARNING, "Exception while pinging server", e);
res = false;
}
// stop when we receive a pong back
if (res) {
break;
}
}
if (!res) {
for (PingFailedListener l : pingFailedListeners) {
l.pingFailed();
}
} else {
// Ping was successful, wind-up the periodic task again
maybeSchedulePingServerTask();
}
} else {
LOGGER.warning("XMPPConnection was not authenticated");
}
}
private final Runnable pingServerRunnable = new Runnable() {
public void run() {
LOGGER.fine("ServerPingTask run()");
pingServerIfNecessary();
}
};
@Override
protected void finalize() throws Throwable {
LOGGER.fine("finalizing PingManager: Shutting down executor service");
try {
executorService.shutdown();
} catch (Throwable t) {
LOGGER.log(Level.WARNING, "finalize() threw throwable", t);
}
finally {
super.finalize();
}
}
}