Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | /** |
| 2 | * $RCSfile$ |
| 3 | * $Revision$ |
| 4 | * $Date$ |
| 5 | * |
| 6 | * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | package org.jivesoftware.smack;
|
| 19 |
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| 20 | import org.jivesoftware.smack.packet.StreamError;
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| 21 | import java.util.Random;
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| 22 | /**
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| 23 | * Handles the automatic reconnection process. Every time a connection is dropped without
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| 24 | * the application explictly closing it, the manager automatically tries to reconnect to
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| 25 | * the server.<p>
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| 26 | *
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| 27 | * The reconnection mechanism will try to reconnect periodically:
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| 28 | * <ol>
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| 29 | * <li>For the first minute it will attempt to connect once every ten seconds.
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| 30 | * <li>For the next five minutes it will attempt to connect once a minute.
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| 31 | * <li>If that fails it will indefinitely try to connect once every five minutes.
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| 32 | * </ol>
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| 33 | *
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| 34 | * @author Francisco Vives
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| 35 | */
|
| 36 | public class ReconnectionManager implements ConnectionListener {
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| 37 |
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| 38 | // Holds the connection to the server
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| 39 | private Connection connection;
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| 40 | private Thread reconnectionThread;
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| 41 | private int randomBase = new Random().nextInt(11) + 5; // between 5 and 15 seconds
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| 42 |
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| 43 | // Holds the state of the reconnection
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| 44 | boolean done = false;
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| 45 |
|
| 46 | static {
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| 47 | // Create a new PrivacyListManager on every established connection. In the init()
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| 48 | // method of PrivacyListManager, we'll add a listener that will delete the
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| 49 | // instance when the connection is closed.
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| 50 | Connection.addConnectionCreationListener(new ConnectionCreationListener() {
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| 51 | public void connectionCreated(Connection connection) {
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| 52 | connection.addConnectionListener(new ReconnectionManager(connection));
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| 53 | }
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| 54 | });
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| 55 | }
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| 56 |
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| 57 | private ReconnectionManager(Connection connection) {
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| 58 | this.connection = connection;
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| 59 | }
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| 60 |
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| 61 |
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| 62 | /**
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| 63 | * Returns true if the reconnection mechanism is enabled.
|
| 64 | *
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| 65 | * @return true if automatic reconnections are allowed.
|
| 66 | */
|
| 67 | private boolean isReconnectionAllowed() {
|
| 68 | return !done && !connection.isConnected() |
| 69 | && connection.isReconnectionAllowed(); |
| 70 | }
|
| 71 |
|
| 72 | /**
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| 73 | * Starts a reconnection mechanism if it was configured to do that.
|
| 74 | * The algorithm is been executed when the first connection error is detected.
|
| 75 | * <p/>
|
| 76 | * The reconnection mechanism will try to reconnect periodically in this way:
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| 77 | * <ol>
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| 78 | * <li>First it will try 6 times every 10 seconds.
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| 79 | * <li>Then it will try 10 times every 1 minute.
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| 80 | * <li>Finally it will try indefinitely every 5 minutes.
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| 81 | * </ol>
|
| 82 | */
|
| 83 | synchronized protected void reconnect() {
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| 84 | if (this.isReconnectionAllowed()) {
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| 85 | // Since there is no thread running, creates a new one to attempt
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| 86 | // the reconnection.
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| 87 | // avoid to run duplicated reconnectionThread -- fd: 16/09/2010
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| 88 | if (reconnectionThread!=null && reconnectionThread.isAlive()) return;
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| 89 |
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| 90 | reconnectionThread = new Thread() {
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| 91 |
|
| 92 | /**
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| 93 | * Holds the current number of reconnection attempts
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| 94 | */
|
| 95 | private int attempts = 0;
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| 96 |
|
| 97 | /**
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| 98 | * Returns the number of seconds until the next reconnection attempt.
|
| 99 | *
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| 100 | * @return the number of seconds until the next reconnection attempt.
|
| 101 | */
|
| 102 | private int timeDelay() {
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| 103 | attempts++;
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| 104 | if (attempts > 13) {
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| 105 | return randomBase*6*5; // between 2.5 and 7.5 minutes (~5 minutes)
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| 106 | }
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| 107 | if (attempts > 7) {
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| 108 | return randomBase*6; // between 30 and 90 seconds (~1 minutes)
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| 109 | }
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| 110 | return randomBase; // 10 seconds
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| 111 | }
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| 112 |
|
| 113 | /**
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| 114 | * The process will try the reconnection until the connection succeed or the user
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| 115 | * cancell it
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| 116 | */
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| 117 | public void run() {
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| 118 | // The process will try to reconnect until the connection is established or
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| 119 | // the user cancel the reconnection process {@link Connection#disconnect()}
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| 120 | while (ReconnectionManager.this.isReconnectionAllowed()) {
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| 121 | // Find how much time we should wait until the next reconnection
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| 122 | int remainingSeconds = timeDelay();
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| 123 | // Sleep until we're ready for the next reconnection attempt. Notify
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| 124 | // listeners once per second about how much time remains before the next
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| 125 | // reconnection attempt.
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| 126 | while (ReconnectionManager.this.isReconnectionAllowed() &&
|
| 127 | remainingSeconds > 0)
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| 128 | {
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| 129 | try {
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| 130 | Thread.sleep(1000);
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| 131 | remainingSeconds--;
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| 132 | ReconnectionManager.this
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| 133 | .notifyAttemptToReconnectIn(remainingSeconds);
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| 134 | }
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| 135 | catch (InterruptedException e1) {
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| 136 | e1.printStackTrace();
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| 137 | // Notify the reconnection has failed
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| 138 | ReconnectionManager.this.notifyReconnectionFailed(e1);
|
| 139 | }
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| 140 | }
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| 141 |
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| 142 | // Makes a reconnection attempt
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| 143 | try {
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| 144 | if (ReconnectionManager.this.isReconnectionAllowed()) {
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| 145 | connection.connect();
|
| 146 | }
|
| 147 | }
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| 148 | catch (XMPPException e) {
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| 149 | // Fires the failed reconnection notification
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| 150 | ReconnectionManager.this.notifyReconnectionFailed(e);
|
| 151 | }
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| 152 | }
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| 153 | }
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| 154 | };
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| 155 | reconnectionThread.setName("Smack Reconnection Manager");
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| 156 | reconnectionThread.setDaemon(true);
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| 157 | reconnectionThread.start();
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| 158 | }
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| 159 | }
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| 160 |
|
| 161 | /**
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| 162 | * Fires listeners when a reconnection attempt has failed.
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| 163 | *
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| 164 | * @param exception the exception that occured.
|
| 165 | */
|
| 166 | protected void notifyReconnectionFailed(Exception exception) {
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| 167 | if (isReconnectionAllowed()) { |
| 168 | for (ConnectionListener listener : connection.connectionListeners) { |
| 169 | listener.reconnectionFailed(exception);
|
| 170 | }
|
| 171 | }
|
| 172 | }
|
| 173 |
|
| 174 | /**
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| 175 | * Fires listeners when The Connection will retry a reconnection. Expressed in seconds.
|
| 176 | *
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| 177 | * @param seconds the number of seconds that a reconnection will be attempted in.
|
| 178 | */
|
| 179 | protected void notifyAttemptToReconnectIn(int seconds) {
|
| 180 | if (isReconnectionAllowed()) { |
| 181 | for (ConnectionListener listener : connection.connectionListeners) { |
| 182 | listener.reconnectingIn(seconds);
|
| 183 | }
|
| 184 | }
|
| 185 | }
|
| 186 |
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| 187 | public void connectionClosed() {
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| 188 | done = true;
|
| 189 | }
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| 190 |
|
| 191 | public void connectionClosedOnError(Exception e) {
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| 192 | done = false;
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| 193 | if (e instanceof XMPPException) {
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| 194 | XMPPException xmppEx = (XMPPException) e;
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| 195 | StreamError error = xmppEx.getStreamError();
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| 196 |
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| 197 | // Make sure the error is not null
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| 198 | if (error != null) {
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| 199 | String reason = error.getCode();
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| 200 |
|
| 201 | if ("conflict".equals(reason)) {
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| 202 | return;
|
| 203 | }
|
| 204 | }
|
| 205 | }
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| 206 |
|
| 207 | if (this.isReconnectionAllowed()) {
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| 208 | this.reconnect();
|
| 209 | }
|
| 210 | }
|
| 211 |
|
| 212 | public void reconnectingIn(int seconds) {
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| 213 | // ignore
|
| 214 | }
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| 215 |
|
| 216 | public void reconnectionFailed(Exception e) {
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| 217 | // ignore
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| 218 | }
|
| 219 |
|
| 220 | /**
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| 221 | * The connection has successfull gotten connected.
|
| 222 | */
|
| 223 | public void reconnectionSuccessful() {
|
| 224 | // ignore
|
| 225 | }
|
| 226 |
|
| 227 | } |