/** * $RCSfile$ * $Revision$ * $Date$ * * Copyright (C) 2002-2003 Jive Software. All rights reserved. * ==================================================================== * The Jive Software License (based on Apache Software License, Version 1.1) * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by * Jive Software (http://www.jivesoftware.com)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Smack" and "Jive Software" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please * contact webmaster@jivesoftware.com. * * 5. Products derived from this software may not be called "Smack", * nor may "Smack" appear in their name, without prior written * permission of Jive Software. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL JIVE SOFTWARE OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== */ package org.jivesoftware.smackx; import java.util.*; import org.jivesoftware.smack.*; import org.jivesoftware.smack.filter.*; import org.jivesoftware.smack.packet.*; import org.jivesoftware.smackx.packet.*; /** * A MultiUserChat is a conversation that takes place among many users in a virtual * room. A room could have many occupants with different affiliation and roles. * Possible affiliatons are "owner", "admin", "member", and "outcast". Possible roles * are "moderator", "participant", and "visitor". Each role and affiliation guarantees * different privileges (e.g. Send messages to all occupants, Kick participants and visitors, * Grant voice, Edit member list, etc.). * * @author Gaston Dombiak */ public class MultiUserChat { private XMPPConnection connection; private String room; private String nickname = null; private boolean joined = false; private Map participantsMap = new HashMap(); private List invitationRejectionListeners = new ArrayList(); private PacketFilter presenceFilter; private PacketListener presenceListener; private PacketFilter messageFilter; private PacketFilter declinesFilter; private PacketListener declinesListener; private PacketCollector messageCollector; /** * Creates a new multi user chat with the specified connection and room name. Note: no * information is sent to or received from the server until you attempt to * {@link #join(String) join} the chat room. On some server implementations, * the room will not be created until the first person joins it.

* * Most XMPP servers use a sub-domain for the chat service (eg chat.example.com * for the XMPP server example.com). You must ensure that the room address you're * trying to connect to includes the proper chat sub-domain. * * @param connection the XMPP connection. * @param room the name of the room in the form "roomName@service", where * "service" is the hostname at which the multi-user chat * service is running. */ public MultiUserChat(XMPPConnection connection, String room) { this.connection = connection; this.room = room; // Create a collector for all incoming messages. messageFilter = new AndFilter(new FromContainsFilter(room), new PacketTypeFilter(Message.class)); messageFilter = new AndFilter(messageFilter, new PacketFilter() { public boolean accept(Packet packet) { Message msg = (Message) packet; return msg.getType() == Message.Type.GROUP_CHAT; } }); messageCollector = connection.createPacketCollector(messageFilter); // Create a listener for all presence updates. presenceFilter = new AndFilter(new FromContainsFilter(room), new PacketTypeFilter(Presence.class)); presenceListener = new PacketListener() { public void processPacket(Packet packet) { Presence presence = (Presence) packet; String from = presence.getFrom(); if (presence.getType() == Presence.Type.AVAILABLE) { synchronized (participantsMap) { if (!participantsMap.containsKey(from)) { participantsMap.put(from, presence); } } } else if (presence.getType() == Presence.Type.UNAVAILABLE) { synchronized (participantsMap) { participantsMap.remove(from); } } } }; connection.addPacketListener(presenceListener, presenceFilter); // Listens for all messages that include a MUCUser extension and fire the invitation // rejection listeners if the message includes an invitation rejection. declinesFilter = new PacketExtensionFilter("x", "http://jabber.org/protocol/muc#user"); declinesListener = new PacketListener() { public void processPacket(Packet packet) { // Get the MUC User extension MUCUser mucUser = getMUCUserExtension(packet); // Check if the MUCUser informs that the invitee has declined the invitation if (mucUser.getDecline() != null) { // Fire event for invitation rejection listeners fireInvitationRejectionListeners( mucUser.getDecline().getFrom(), mucUser.getDecline().getReason()); } }; }; connection.addPacketListener(declinesListener, declinesFilter); } /** * Returns the name of the room this GroupChat object represents. * * @return the groupchat room name. */ public String getRoom() { return room; } /** * Creates the room according to some default configuration, assign the requesting user * as the room owner, and add the owner to the room but not allow anyone else to enter * the room (effectively "locking" the room). The requesting user will join the room * under the specified nickname as soon as the room has been created.

* * To create an "Instant Room", that means a room with some default configuration that is * available for immediate access, the room's owner should send an empty form after creating * the room. (@see MultiUserChat.sendConfigurationForm(Form))

* * To create a "Reserved Room", that means a room manually configured by the room creator * before anyone is allowed to enter, the room's owner should complete and send a form after * creating the room. Once the completed configutation form is sent to the server, the server * will unlock the room. (@see MultiUserChat.sendConfigurationForm(Form)) * * @param nickname the nickname to use. * @throws XMPPException if the room couldn't be created for some reason * (e.g. room already exists; user already joined to an existant room or * 405 error if the user is not allowed to create the room) */ public void create(String nickname) throws XMPPException { if (nickname == null || nickname.equals("")) { throw new IllegalArgumentException("Nickname must not be null or blank."); } // If we've already joined the room, leave it before joining under a new // nickname. if (joined) { throw new IllegalStateException("Creation failed - User already joined the room."); } // We create a room by sending a presence packet to room@service/nick // and signal support for MUC. The owner will be automatically logged into the room. Presence joinPresence = new Presence(Presence.Type.AVAILABLE); joinPresence.setTo(room + "/" + nickname); // Indicate the the client supports MUC joinPresence.addExtension(new MUCInitialPresence()); // Wait for a presence packet back from the server. PacketFilter responseFilter = new AndFilter( new FromContainsFilter(room + "/" + nickname), new PacketTypeFilter(Presence.class)); PacketCollector response = connection.createPacketCollector(responseFilter); // Send create & join packet. connection.sendPacket(joinPresence); // Wait up to a certain number of seconds for a reply. Presence presence = (Presence) response.nextResult(SmackConfiguration.getPacketReplyTimeout()); if (presence == null) { throw new XMPPException("No response from server."); } else if (presence.getError() != null) { throw new XMPPException(presence.getError()); } // Whether the room existed before or was created, the user has joined the room this.nickname = nickname; joined = true; // Look for confirmation of room creation from the server MUCUser mucUser = getMUCUserExtension(presence); if (mucUser != null && mucUser.getStatus() != null) { if ("201".equals(mucUser.getStatus().getCode())) { // Room was created and the user has joined the room return; } } // We need to leave the room since it seems that the room already existed leave(); throw new XMPPException("Creation failed - Missing acknowledge of room creation."); } /** * Joins the chat room using the specified nickname. If already joined * using another nickname, this method will first leave the room and then * re-join using the new nickname. The default timeout of Smack for a reply * from the group chat server that the join succeeded will be used. After * joining the room, the room will decide the amount of history to send. * * @param nickname the nickname to use. * @throws XMPPException if an error occurs joining the room. In particular, a * 401 error can occur if no password was provided and one is required; or a * 403 error can occur if the user is banned; or a * 404 error can occur if the room does not exist or is locked; or a * 407 error can occur if user is not on the member list; or a * 409 error can occur if someone is already in the group chat with the same nickname. */ public void join(String nickname) throws XMPPException { join(nickname, SmackConfiguration.getPacketReplyTimeout(), null, -1, -1, -1, null); } /** * Joins the chat room using the specified nickname and password. If already joined * using another nickname, this method will first leave the room and then * re-join using the new nickname. The default timeout of Smack for a reply * from the group chat server that the join succeeded will be used. After * joining the room, the room will decide the amount of history to send.

* * A password is required when joining password protected rooms. If the room does * not require a password there is no need to provide one. * * @param nickname the nickname to use. * @param password the password to use. * @throws XMPPException if an error occurs joining the room. In particular, a * 401 error can occur if no password was provided and one is required; or a * 403 error can occur if the user is banned; or a * 404 error can occur if the room does not exist or is locked; or a * 407 error can occur if user is not on the member list; or a * 409 error can occur if someone is already in the group chat with the same nickname. */ public void join(String nickname, String password) throws XMPPException { join(nickname, SmackConfiguration.getPacketReplyTimeout(), password, -1, -1, -1, null); } /** * Joins the chat room using the specified nickname and password. If already joined * using another nickname, this method will first leave the room and then * re-join using the new nickname.

* * This method provides different parameters to control the amount of history to receive when * joining the room. If you don't complete any of these parameters the room will decide the * amount of history to return. If you decide to control the amount of history to receive, you * can use some or all of the following parameters: *

* * A password is required when joining password protected rooms. If the room does * not require a password there is no need to provide one.

* * If the room does not already exist when the user seeks to enter it, the server will * decide to create a new room or not. * * @param nickname the nickname to use. * @param timeout the number of seconds to wait for reply from the group chat server. * @param password the password to use. * @param maxchars the total number of characters to receive in the history. * @param maxstanzas the total number of messages to receive in the history. * @param seconds the number of seconds to use to filter the messages received during * that time. * @param since the since date to use to filter the messages received during that time. * @throws XMPPException if an error occurs joining the room. In particular, a * 401 error can occur if no password was provided and one is required; or a * 403 error can occur if the user is banned; or a * 404 error can occur if the room does not exist or is locked; or a * 407 error can occur if user is not on the member list; or a * 409 error can occur if someone is already in the group chat with the same nickname. */ public synchronized void join( String nickname, long timeout, String password, int maxchars, int maxstanzas, int seconds, Date since) throws XMPPException { // TODO Review protocol (too many params). Use setters or history class? if (nickname == null || nickname.equals("")) { throw new IllegalArgumentException("Nickname must not be null or blank."); } // If we've already joined the room, leave it before joining under a new // nickname. if (joined) { leave(); } // We join a room by sending a presence packet where the "to" // field is in the form "roomName@service/nickname" Presence joinPresence = new Presence(Presence.Type.AVAILABLE); joinPresence.setTo(room + "/" + nickname); // Indicate the the client supports MUC MUCInitialPresence mucInitialPresence = new MUCInitialPresence(); if (password != null) { mucInitialPresence.setPassword(password); } if (maxchars > -1 || maxstanzas > -1 || seconds > -1 || since != null) { MUCInitialPresence.History history = new MUCInitialPresence.History(); if (maxchars > -1) { history.setMaxChars(maxchars); } if (maxstanzas > -1) { history.setMaxStanzas(maxstanzas); } if (seconds > -1) { history.setSeconds(seconds); } if (since != null) { history.setSince(since); } mucInitialPresence.setHistory(history); } joinPresence.addExtension(mucInitialPresence); // Wait for a presence packet back from the server. PacketFilter responseFilter = new AndFilter( new FromContainsFilter(room + "/" + nickname), new PacketTypeFilter(Presence.class)); PacketCollector response = connection.createPacketCollector(responseFilter); // Send join packet. connection.sendPacket(joinPresence); // Wait up to a certain number of seconds for a reply. Presence presence = (Presence) response.nextResult(timeout); if (presence == null) { throw new XMPPException("No response from server."); } else if (presence.getError() != null) { throw new XMPPException(presence.getError()); } this.nickname = nickname; joined = true; } /** * Returns true if currently in the group chat (after calling the {@link * #join(String)} method. * * @return true if currently in the group chat room. */ public boolean isJoined() { return joined; } /** * Leave the chat room. */ public synchronized void leave() { // If not joined already, do nothing. if (!joined) { return; } // We leave a room by sending a presence packet where the "to" // field is in the form "roomName@service/nickname" Presence leavePresence = new Presence(Presence.Type.UNAVAILABLE); leavePresence.setTo(room + "/" + nickname); connection.sendPacket(leavePresence); // Reset participant information. participantsMap = new HashMap(); nickname = null; joined = false; } /** * Returns the room's configuration form that the room's owner can use or null if * no configuration is possible. The configuration form allows to set the room's language, * enable logging, specify room's type, etc.. * * @return the Form that contains the fields to complete together with the instrucions or * null if no configuration is possible. * @throws XMPPException if an error occurs asking the configuration form for the room. */ public Form getConfigurationForm() throws XMPPException { MUCOwner iq = new MUCOwner(); iq.setTo(room); iq.setType(IQ.Type.GET); // Wait for a presence packet back from the server. PacketFilter responseFilter = new AndFilter(new FromContainsFilter(room), new PacketTypeFilter(IQ.class)); PacketCollector response = connection.createPacketCollector(responseFilter); // Request the configuration form to the server. connection.sendPacket(iq); // Wait up to a certain number of seconds for a reply. IQ answer = (IQ) response.nextResult(SmackConfiguration.getPacketReplyTimeout()); // Stop queuing results response.cancel(); if (answer == null) { throw new XMPPException("No response from server."); } else if (answer.getError() != null) { throw new XMPPException(answer.getError()); } return Form.getFormFrom(answer); } /** * Sends the completed configuration form to the server. The room will be configured * with the new settings defined in the form. If the form is empty then the server * will create an instant room (will use default configuration). * * @param form the form with the new settings. * @throws XMPPException if an error occurs setting the new rooms' configuration. */ public void sendConfigurationForm(Form form) throws XMPPException { MUCOwner iq = new MUCOwner(); iq.setTo(room); iq.setType(IQ.Type.SET); iq.addExtension(form.getDataFormToSend()); // Send the completed configuration form to the server. connection.sendPacket(iq); // TODO Check for possible returned errors? permission errors? // TODO Check that the form is of type "submit" or "cancel" } /** * Sends a request to the server to destroy the room. The sender of the request * should be the room's owner. If the sender of the destroy request is not the room's owner * then the server will answer a "Forbidden" error (403). * * @param reason the reason for the room destruction. * @param alternateJID the JID of an alternate location. * @throws XMPPException if an error occurs while trying to destroy the room. * An error can occur which will be wrapped by an XMPPException -- * XMPP error code 403. The error code can be used to present more * appropiate error messages to end-users. */ public void destroy(String reason, String alternateJID) throws XMPPException { MUCOwner iq = new MUCOwner(); iq.setTo(room); iq.setType(IQ.Type.SET); // Create the reason for the room destruction MUCOwner.Destroy destroy = new MUCOwner.Destroy(); destroy.setReason(reason); destroy.setJid(alternateJID); iq.setDestroy(destroy); // Wait for a presence packet back from the server. PacketFilter responseFilter = new AndFilter(new FromContainsFilter(room), new PacketTypeFilter(IQ.class)); PacketCollector response = connection.createPacketCollector(responseFilter); // Send the room destruction request. connection.sendPacket(iq); // Wait up to a certain number of seconds for a reply. IQ answer = (IQ) response.nextResult(SmackConfiguration.getPacketReplyTimeout()); // Stop queuing results response.cancel(); if (answer == null) { throw new XMPPException("No response from server."); } else if (answer.getError() != null) { throw new XMPPException(answer.getError()); } } /** * Invites another user to the room in which one is an occupant. The invitation * will be sent to the room which in turn will forward the invitation to the invitee.

* * If the room is password-protected, the invitee will receive a password to use to join * the room. If the room is members-only, the the invitee may be added to the member list. * * @param participant the user to invite to the room.(e.g. hecate@shakespeare.lit) * @param reason the reason why the user is being invited. */ public void invite(String participant, String reason) { // TODO listen for 404 error code when inviter supplies a non-existent JID Message message = new Message(room); // Create the MUCUser packet that will include the invitation MUCUser mucUser = new MUCUser(); MUCUser.Invite invite = new MUCUser.Invite(); invite.setTo(participant); invite.setReason(reason); mucUser.setInvite(invite); // Add the MUCUser packet that includes the invitation to the message message.addExtension(mucUser); connection.sendPacket(message); } /** * Informs the sender of an invitation that the invitee declines the invitation. The rejection * will be sent to the room which in turn will forward the rejection to the inviter. * * @param conn the connection to use for sending the rejection. * @param room the room that sent the original invitation. * @param inviter the inviter of the declined invitation. * @param reason the reason why the invitee is declining the invitation. */ public static void decline(XMPPConnection conn, String room, String inviter, String reason) { Message message = new Message(room); // Create the MUCUser packet that will include the rejection MUCUser mucUser = new MUCUser(); MUCUser.Decline decline = new MUCUser.Decline(); decline.setTo(inviter); decline.setReason(reason); mucUser.setDecline(decline); // Add the MUCUser packet that includes the rejection message.addExtension(mucUser); conn.sendPacket(message); } public static void addInvitationListener(XMPPConnection conn, InvitationListener listener) { //TODO Implement the InvitationListener functionality } /** * Adds a listener to invitation rejections notifications. The listener will be fired anytime * an invitation is declined. * * @param listener an invitation rejection listener. */ public void addInvitationRejectionListener(InvitationRejectionListener listener) { synchronized (invitationRejectionListeners) { if (!invitationRejectionListeners.contains(listener)) { invitationRejectionListeners.add(listener); } } } /** * Removes a listener from invitation rejections notifications. The listener will be fired * anytime an invitation is declined. * * @param listener an invitation rejection listener. */ public void removeInvitationRejectionListener(InvitationRejectionListener listener) { synchronized (invitationRejectionListeners) { invitationRejectionListeners.remove(listener); } } /** * Fires invitation rejection listeners. */ private void fireInvitationRejectionListeners(String invitee, String reason) { InvitationRejectionListener[] listeners = null; synchronized (invitationRejectionListeners) { listeners = new InvitationRejectionListener[invitationRejectionListeners.size()]; invitationRejectionListeners.toArray(listeners); } for (int i = 0; i < listeners.length; i++) { listeners[i].invitationDeclined(invitee, reason); } } /** * Returns the nickname that was used to join the room, or null if not * currently joined. * * @return the nickname currently being used. */ public String getNickname() { return nickname; } /** * Changes the participant's nickname to a new nickname within the room. Each room participant * will receive two presence packets. One of type "unavailable" for the old nickname and one * indicating availability for the new nickname. The unavailable presence will contain the new * nickname and an appropriate status code (namely 303) as extended presence information. The * status code 303 indicates that the participant is changing his/her nickname. * * @param nickname the new nickname within the room. * @throws XMPPException if the new nickname is already in use by another occupant. */ public void changeNickname(String nickname) throws XMPPException { if (nickname == null || nickname.equals("")) { throw new IllegalArgumentException("Nickname must not be null or blank."); } // Check that we already have joined the room before attempting to change the // nickname. if (!joined) { throw new IllegalStateException("Must be logged into the room to change nickname."); } // We change the nickname by sending a presence packet where the "to" // field is in the form "roomName@service/nickname" // We don't have to signal the MUC support again Presence joinPresence = new Presence(Presence.Type.AVAILABLE); joinPresence.setTo(room + "/" + nickname); // Wait for a presence packet back from the server. PacketFilter responseFilter = new AndFilter( new FromContainsFilter(room + "/" + nickname), new PacketTypeFilter(Presence.class)); PacketCollector response = connection.createPacketCollector(responseFilter); // Send join packet. connection.sendPacket(joinPresence); // Wait up to a certain number of seconds for a reply. Presence presence = (Presence) response.nextResult(SmackConfiguration.getPacketReplyTimeout()); if (presence == null) { throw new XMPPException("No response from server."); } else if (presence.getError() != null) { throw new XMPPException(presence.getError()); } this.nickname = nickname; } /** * Changes the participant's availability status within the room. The presence type * will remain available but with a new status that describes the presence update and * a new presence mode (e.g. Extended away). * * @param status a text message describing the presence update. * @param mode the mode type for the presence update. */ public void changeAvailabilityStatus(String status, Presence.Mode mode) { if (nickname == null || nickname.equals("")) { throw new IllegalArgumentException("Nickname must not be null or blank."); } // Check that we already have joined the room before attempting to change the // availability status. if (!joined) { throw new IllegalStateException( "Must be logged into the room to change the " + "availability status."); } // We change the availability status by sending a presence packet to the room with the // new presence status and mode Presence joinPresence = new Presence(Presence.Type.AVAILABLE); joinPresence.setStatus(status); joinPresence.setMode(mode); joinPresence.setTo(room + "/" + nickname); // Send join packet. connection.sendPacket(joinPresence); } /** * Returns the number of participants in the group chat.

* * Note: this value will only be accurate after joining the group chat, and * may fluctuate over time. If you query this value directly after joining the * group chat it may not be accurate, as it takes a certain amount of time for * the server to send all presence packets to this client. * * @return the number of participants in the group chat. */ public int getParticipantCount() { synchronized (participantsMap) { return participantsMap.size(); } } /** * Returns an Iterator (of Strings) for the list of fully qualified participants * in the group chat. For example, "conference@chat.jivesoftware.com/SomeUser". * Typically, a client would only display the nickname of the participant. To * get the nickname from the fully qualified name, use the * {@link org.jivesoftware.smack.util.StringUtils#parseResource(String)} method. * Note: this value will only be accurate after joining the group chat, and may * fluctuate over time. * * @return an Iterator for the participants in the group chat. */ public Iterator getParticipants() { synchronized (participantsMap) { return Collections.unmodifiableList(new ArrayList(participantsMap.keySet())).iterator(); } } /** * Returns the participant's full JID when joining a Non-Anonymous room or null * if the room is of type anonymous. If the room is of type semi-anonymous only the * moderators will have access to the participants full JID. * * @param participant the room occupant to search for his JID. Format roomName@service/nickname * (e.g. darkcave@macbeth.shakespeare.lit/thirdwitch) * @return the participant's full JID when joining a Non-Anonymous room otherwise returns * null. */ public String getParticipantJID(String participant) { // Get the participant's presence Presence presence = (Presence) participantsMap.get(participant); // Get the MUC User extension MUCUser mucUser = getMUCUserExtension(presence); if (mucUser != null) { return mucUser.getItem().getJid(); } return null; } /** * Adds a packet listener that will be notified of any new Presence packets * sent to the group chat. Using a listener is a suitable way to know when the list * of participants should be re-loaded due to any changes. * * @param listener a packet listener that will be notified of any presence packets * sent to the group chat. */ public void addParticipantListener(PacketListener listener) { connection.addPacketListener(listener, presenceFilter); } /** * Sends a message to the chat room. * * @param text the text of the message to send. * @throws XMPPException if sending the message fails. */ public void sendMessage(String text) throws XMPPException { Message message = new Message(room, Message.Type.GROUP_CHAT); message.setBody(text); connection.sendPacket(message); } /** * Returns a new Chat for sending private messages to a given room participant. * The Chat's participant address is the room's JID (i.e. roomName@service/nick). The server * service will change the 'from' address to the sender's room JID and delivering the message * to the intended recipient's full JID. * * @param participant occupant unique room JID (e.g. 'darkcave@macbeth.shakespeare.lit/Paul'). * @return new Chat for sending private messages to a given room participant. */ public Chat createPrivateChat(String participant) { return new Chat(connection, participant); } /** * Creates a new Message to send to the chat room. * * @return a new Message addressed to the chat room. */ public Message createMessage() { return new Message(room, Message.Type.GROUP_CHAT); } /** * Sends a Message to the chat room. * * @param message the message. * @throws XMPPException if sending the message fails. */ public void sendMessage(Message message) throws XMPPException { connection.sendPacket(message); } /** * Polls for and returns the next message, or null if there isn't * a message immediately available. This method provides significantly different * functionalty than the {@link #nextMessage()} method since it's non-blocking. * In other words, the method call will always return immediately, whereas the * nextMessage method will return only when a message is available (or after * a specific timeout). * * @return the next message if one is immediately available and * null otherwise. */ public Message pollMessage() { return (Message) messageCollector.pollResult(); } /** * Returns the next available message in the chat. The method call will block * (not return) until a message is available. * * @return the next message. */ public Message nextMessage() { return (Message) messageCollector.nextResult(); } /** * Returns the next available message in the chat. The method call will block * (not return) until a packet is available or the timeout has elapased. * If the timeout elapses without a result, null will be returned. * * @param timeout the maximum amount of time to wait for the next message. * @return the next message, or null if the timeout elapses without a * message becoming available. */ public Message nextMessage(long timeout) { return (Message) messageCollector.nextResult(timeout); } /** * Adds a packet listener that will be notified of any new messages in the * group chat. Only "group chat" messages addressed to this group chat will * be delivered to the listener. If you wish to listen for other packets * that may be associated with this group chat, you should register a * PacketListener directly with the XMPPConnection with the appropriate * PacketListener. * * @param listener a packet listener. */ public void addMessageListener(PacketListener listener) { connection.addPacketListener(listener, messageFilter); } /** * Returns the MUCUser packet extension included in the packet or null if none. * * @param packet the packet that may include the MUCUser extension. * @return the MUCUser found in the packet. */ private MUCUser getMUCUserExtension(Packet packet) { if (packet != null) { // Get the MUC User extension return (MUCUser) packet.getExtension("x", "http://jabber.org/protocol/muc#user"); } return null; } public void finalize() { if (connection != null) { connection.removePacketListener(presenceListener); connection.removePacketListener(declinesListener); } } }