package org.jivesoftware.smack; import java.util.ArrayList; import java.util.List; /** * 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.

* * The reconnection mechanism will try to reconnect periodically: *

    *
  1. First it will try 6 times every 10 seconds. *
  2. Then it will try 10 times every 1 minute. *
  3. Finally it will try indefinitely every 5 minutes. *
* * @author Francisco Vives */ public class ReconnectionManager implements ConnectionListener { // Holds the time elapsed between each reconnection attempt private int secondBetweenReconnection = 5 * 60; // 5 minutes // Holds the thread that produces a periodical reconnection. private Thread reconnectionThread; // Holds the connection to the server private XMPPConnection connection; // Holds the state of the reconnection boolean done = false; static { // Create a new PrivacyListManager on every established connection. In the init() // method of PrivacyListManager, we'll add a listener that will delete the // instance when the connection is closed. XMPPConnection.addConnectionEstablishedListener(new ConnectionEstablishedListener() { public void connectionEstablished(XMPPConnection connection) { connection.addConnectionListener(new ReconnectionManager(connection)); } }); } private ReconnectionManager(XMPPConnection connection) { this.connection = connection; } /** * Returns true if the reconnection mechanism is enabled. * * @return true if automatic reconnections are allowed. */ private boolean isReconnectionAllowed() { return !done && !connection.isConnected() && connection.getConfiguration().isReconnectionAllowed() && connection.packetReader != null; } /** * Returns the time elapsed between each reconnection attempt. * By default it will try to reconnect every 5 minutes. * It is used when the client has lost the server connection and the XMPPConnection * automatically tries to reconnect. * * @return Returns the number of seconds between reconnection. */ private int getSecondBetweenReconnection() { return secondBetweenReconnection; } /** * Sets the time elapsed between each reconnection attempt. * It is used when the client has lost the server connection and the XMPPConnection * automatically tries to reconnect. * * @param secondBetweenReconnection The number of seconds between reconnection. */ protected void setSecondBetweenReconnection( int secondBetweenReconnection) { this.secondBetweenReconnection = secondBetweenReconnection; } /** * Starts a reconnection mechanism if it was configured to do that. * The algorithm is been executed when the first connection error is detected. *

* The reconnection mechanism will try to reconnect periodically in this way: *

    *
  1. First it will try 6 times every 10 seconds. *
  2. Then it will try 10 times every 1 minute. *
  3. Finally it will try indefinitely every 5 minutes. *
*/ protected void reconnect() { if (this.isReconnectionAllowed() && reconnectionThread == null) { // Since there is no thread running, creates a new one to attempt // the reconnection. reconnectionThread = new Thread() { /** * Holds the number of reconnection attempts */ private int attempts = 0; private int firstReconnectionPeriod = 7; // 6 attempts private int secondReconnectionPeriod = 10 + firstReconnectionPeriod; // 16 attempts private int firstReconnectionTime = 10; // 10 seconds private int secondReconnectionTime = 60; // 1 minute private int lastReconnectionTime = getSecondBetweenReconnection(); // user defined in seconds private int remainingSeconds = 0; // The seconds remaining to a reconnection private int notificationPeriod = 1000; // 1 second /** * Returns the amount of time until the next reconnection attempt. * * @return the amount of time until the next reconnection attempt. */ private int timeDelay() { if (attempts > secondReconnectionPeriod) { return lastReconnectionTime; // 5 minutes } if (attempts > firstReconnectionPeriod) { return secondReconnectionTime; // 1 minute } return firstReconnectionTime; // 10 seconds } /** * The process will try the reconnection until the connection succeed or the user * cancell it */ public void run() { // The process will try to reconnect until the connection is established or // the user cancel the reconnection process {@link XMPPConnection#disconnect()} while (ReconnectionManager.this.isReconnectionAllowed()) { // Indicate how much time will wait until next reconnection remainingSeconds = timeDelay(); // Notifies the remaining time until the next reconnection attempt // every 1 second. while (ReconnectionManager.this.isReconnectionAllowed() && remainingSeconds > 0) { try { Thread.sleep(notificationPeriod); remainingSeconds = remainingSeconds - 1; ReconnectionManager.this .notifyAttemptToReconnectIn(remainingSeconds); } catch (InterruptedException e1) { e1.printStackTrace(); // Notify the reconnection has failed ReconnectionManager.this.notifyReconnectionFailed(e1); } } // Waiting time have finished // Makes the reconnection attempt try { if (ReconnectionManager.this.isReconnectionAllowed()) { // Attempts to reconnect. connection.connect(); } } catch (XMPPException e) { // Fires the failed reconnection notification ReconnectionManager.this.notifyReconnectionFailed(e); } } } }; reconnectionThread.setName("Smack Reconnection Manager"); reconnectionThread.setDaemon(true); reconnectionThread.start(); } } /** * Fires listeners when a reconnection attempt has failed. * * @param exception the exception that occured. */ protected void notifyReconnectionFailed(Exception exception) { List listenersCopy; if (isReconnectionAllowed()) { synchronized (connection.packetReader.connectionListeners) { // Makes a copy since it's possible that a listener will be removed from the list listenersCopy = new ArrayList( connection.packetReader.connectionListeners); for (ConnectionListener listener : listenersCopy) { listener.reconnectionFailed(exception); } } } } /** * Fires listeners when The XMPPConnection will retry a reconnection. Expressed in seconds. * * @param seconds the number of seconds that a reconnection will be attempted in. */ protected void notifyAttemptToReconnectIn(int seconds) { List listenersCopy; if (isReconnectionAllowed()) { synchronized (connection.packetReader.connectionListeners) { // Makes a copy since it's possible that a listener will be removed from the list listenersCopy = new ArrayList( connection.packetReader.connectionListeners); for (ConnectionListener listener : listenersCopy) { listener.reconnectingIn(seconds); } } } } public void connectionClosed() { done = true; } public void connectionClosedOnError(Exception e) { done = false; if (this.isReconnectionAllowed()) { this.reconnect(); } } public void reconnectingIn(int seconds) { // ignore } public void reconnectionFailed(Exception e) { // ignore } /** * The connection has successfull gotten connected. */ public void reconectionSuccessful() { // ignore } }