ReconnectionManager.java
/**
*
* Copyright the original author or authors
*
* 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.smack;
import org.jivesoftware.smack.XMPPException.StreamErrorException;
import org.jivesoftware.smack.packet.StreamError;
import org.jivesoftware.smack.util.Async;
import java.lang.ref.WeakReference;
import java.util.Map;
import java.util.Random;
import java.util.WeakHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Handles the automatic reconnection process. Every time a connection is dropped without
* the application explicitly closing it, the manager automatically tries to reconnect to
* the server.<p>
*
* The reconnection mechanism will try to reconnect periodically:
* <ol>
* <li>For the first minute it will attempt to connect once every ten seconds.
* <li>For the next five minutes it will attempt to connect once a minute.
* <li>If that fails it will indefinitely try to connect once every five minutes.
* </ol>
*
* @author Francisco Vives
*/
public class ReconnectionManager {
private static final Logger LOGGER = Logger.getLogger(ReconnectionManager.class.getName());
private static final Map<AbstractXMPPConnection, ReconnectionManager> INSTANCES = new WeakHashMap<AbstractXMPPConnection, ReconnectionManager>();
/**
* Get a instance of ReconnectionManager for the given connection.
*
* @param connection
* @return a ReconnectionManager for the connection.
*/
public static synchronized ReconnectionManager getInstanceFor(AbstractXMPPConnection connection) {
ReconnectionManager reconnectionManager = INSTANCES.get(connection);
if (reconnectionManager == null) {
reconnectionManager = new ReconnectionManager(connection);
INSTANCES.put(connection, reconnectionManager);
}
return reconnectionManager;
}
static {
XMPPConnectionRegistry.addConnectionCreationListener(new ConnectionCreationListener() {
public void connectionCreated(XMPPConnection connection) {
if (connection instanceof AbstractXMPPConnection) {
ReconnectionManager.getInstanceFor((AbstractXMPPConnection) connection);
}
}
});
}
private static boolean enabledPerDefault = false;
/**
* Set if the automatic reconnection mechanism will be enabled per default for new XMPP connections. The default is
* 'false'.
*
* @param enabled
*/
public static void setEnabledPerDefault(boolean enabled) {
enabledPerDefault = enabled;
}
/**
* Get the current default reconnection mechanism setting for new XMPP connections.
*
* @return true if new connection will come with an enabled reconnection mechanism
*/
public static boolean getEnabledPerDefault() {
return enabledPerDefault;
}
// Holds the connection to the server
private final WeakReference<AbstractXMPPConnection> weakRefConnection;
private final int randomBase = new Random().nextInt(13) + 2; // between 2 and 15 seconds
private final Runnable reconnectionRunnable;
/**
* Flag that indicates if a reconnection should be attempted when abruptly disconnected
*/
private boolean automaticReconnectEnabled = false;
boolean done = false;
private Thread reconnectionThread;
private ReconnectionManager(AbstractXMPPConnection connection) {
weakRefConnection = new WeakReference<AbstractXMPPConnection>(connection);
reconnectionRunnable = new Thread() {
/**
* Holds the current number of reconnection attempts
*/
private int attempts = 0;
/**
* Returns the number of seconds until the next reconnection attempt.
*
* @return the number of seconds until the next reconnection attempt.
*/
private int timeDelay() {
attempts++;
if (attempts > 13) {
return randomBase * 6 * 5; // between 2.5 and 7.5 minutes (~5 minutes)
}
if (attempts > 7) {
return randomBase * 6; // between 30 and 90 seconds (~1 minutes)
}
return randomBase; // 10 seconds
}
/**
* The process will try the reconnection until the connection succeed or the user cancel it
*/
public void run() {
final AbstractXMPPConnection connection = weakRefConnection.get();
if (connection == null) {
return;
}
// The process will try to reconnect until the connection is established or
// the user cancel the reconnection process AbstractXMPPConnection.disconnect().
while (isReconnectionPossible(connection)) {
// Find how much time we should wait until the next reconnection
int remainingSeconds = timeDelay();
// Sleep until we're ready for the next reconnection attempt. Notify
// listeners once per second about how much time remains before the next
// reconnection attempt.
while (isReconnectionPossible(connection) && remainingSeconds > 0) {
try {
Thread.sleep(1000);
remainingSeconds--;
for (ConnectionListener listener : connection.connectionListeners) {
listener.reconnectingIn(remainingSeconds);
}
}
catch (InterruptedException e) {
LOGGER.log(Level.FINE, "waiting for reconnection interrupted", e);
break;
}
}
for (ConnectionListener listener : connection.connectionListeners) {
listener.reconnectingIn(0);
}
// Makes a reconnection attempt
try {
if (isReconnectionPossible(connection)) {
connection.connect();
}
}
catch (Exception e) {
// Fires the failed reconnection notification
for (ConnectionListener listener : connection.connectionListeners) {
listener.reconnectionFailed(e);
}
}
}
}
};
// If the reconnection mechanism is enable per default, enable it for this ReconnectionManager instance
if (getEnabledPerDefault()) {
enableAutomaticReconnection();
}
}
/**
* Enable the automatic reconnection mechanism. Does nothing if already enabled.
*/
public synchronized void enableAutomaticReconnection() {
if (automaticReconnectEnabled) {
return;
}
XMPPConnection connection = weakRefConnection.get();
if (connection == null) {
throw new IllegalStateException("Connection instance no longer available");
}
connection.addConnectionListener(connectionListener);
automaticReconnectEnabled = true;
}
/**
* Disable the automatic reconnection mechanism. Does nothing if already disabled.
*/
public synchronized void disableAutomaticReconnection() {
if (!automaticReconnectEnabled) {
return;
}
XMPPConnection connection = weakRefConnection.get();
if (connection == null) {
throw new IllegalStateException("Connection instance no longer available");
}
connection.removeConnectionListener(connectionListener);
automaticReconnectEnabled = false;
}
/**
* Returns if the automatic reconnection mechanism is enabled. You can disable the reconnection mechanism with
* {@link #disableAutomaticReconnection} and enable the mechanism with {@link #enableAutomaticReconnection()}.
*
* @return true, if the reconnection mechanism is enabled.
*/
public boolean isAutomaticReconnectEnabled() {
return automaticReconnectEnabled;
}
/**
* Returns true if the reconnection mechanism is enabled.
*
* @return true if automatic reconnection is allowed.
*/
private boolean isReconnectionPossible(XMPPConnection connection) {
return !done && !connection.isConnected()
&& isAutomaticReconnectEnabled();
}
/**
* Starts a reconnection mechanism if it was configured to do that.
* The algorithm is been executed when the first connection error is detected.
*/
private synchronized void reconnect() {
XMPPConnection connection = this.weakRefConnection.get();
if (connection == null) {
LOGGER.fine("Connection is null, will not reconnect");
return;
}
// Since there is no thread running, creates a new one to attempt
// the reconnection.
// avoid to run duplicated reconnectionThread -- fd: 16/09/2010
if (reconnectionThread != null && reconnectionThread.isAlive())
return;
reconnectionThread = Async.go(reconnectionRunnable,
"Smack Reconnection Manager (" + connection.getConnectionCounter() + ')');
}
private final ConnectionListener connectionListener = new AbstractConnectionListener() {
@Override
public void connectionClosed() {
done = true;
}
@Override
public void authenticated(XMPPConnection connection, boolean resumed) {
done = false;
}
@Override
public void connectionClosedOnError(Exception e) {
done = false;
if (!isAutomaticReconnectEnabled()) {
return;
}
if (e instanceof StreamErrorException) {
StreamErrorException xmppEx = (StreamErrorException) e;
StreamError error = xmppEx.getStreamError();
if (StreamError.Condition.conflict == error.getCondition()) {
return;
}
}
reconnect();
}
};
}