/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://oss.oracle.com/licenses/CDDL+GPL-1.1
 * or LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package javax.mail.event;

import java.util.*;
import javax.mail.*;

This class notifies changes in the number of messages in a folder.

Note that some folder types may only deliver MessageCountEvents at certain times or after certain operations. IMAP in particular will only notify the client of MessageCountEvents when a client issues a new command. Refer to RFC 3501 for details. A client may want to "poll" the folder by occasionally calling the getMessageCount or isOpen methods to solicit any such notifications.

Author:John Mani
/** * This class notifies changes in the number of messages in a folder. <p> * * Note that some folder types may only deliver MessageCountEvents at * certain times or after certain operations. IMAP in particular will * only notify the client of MessageCountEvents when a client issues a * new command. Refer to * <A HREF="http://www.ietf.org/rfc/rfc3501.txt" TARGET="_top">RFC 3501</A> * for details. * A client may want to "poll" the folder by occasionally calling the * {@link javax.mail.Folder#getMessageCount getMessageCount} or * {@link javax.mail.Folder#isOpen isOpen} methods * to solicit any such notifications. * * @author John Mani */
public class MessageCountEvent extends MailEvent {
The messages were added to their folder
/** The messages were added to their folder */
public static final int ADDED = 1;
The messages were removed from their folder
/** The messages were removed from their folder */
public static final int REMOVED = 2;
The event type.
@serial
/** * The event type. * * @serial */
protected int type;
If true, this event is the result of an explicit expunge by this client, and the messages in this folder have been renumbered to account for this. If false, this event is the result of an expunge by external sources.
@serial
/** * If true, this event is the result of an explicit * expunge by this client, and the messages in this * folder have been renumbered to account for this. * If false, this event is the result of an expunge * by external sources. * * @serial */
protected boolean removed;
The messages.
/** * The messages. */
transient protected Message[] msgs; private static final long serialVersionUID = -7447022340837897369L;
Constructor.
Params:
  • folder – The containing folder
  • type – The event type
  • removed – If true, this event is the result of an explicit expunge by this client, and the messages in this folder have been renumbered to account for this. If false, this event is the result of an expunge by external sources.
  • msgs – The messages added/removed
/** * Constructor. * @param folder The containing folder * @param type The event type * @param removed If true, this event is the result of an explicit * expunge by this client, and the messages in this * folder have been renumbered to account for this. * If false, this event is the result of an expunge * by external sources. * * @param msgs The messages added/removed */
public MessageCountEvent(Folder folder, int type, boolean removed, Message[] msgs) { super(folder); this.type = type; this.removed = removed; this.msgs = msgs; }
Return the type of this event.
Returns: type
/** * Return the type of this event. * @return type */
public int getType() { return type; }
Indicates whether this event is the result of an explicit expunge by this client, or due to an expunge from external sources. If true, this event is due to an explicit expunge and hence all remaining messages in this folder have been renumbered. If false, this event is due to an external expunge.

Note that this method is valid only if the type of this event is REMOVED

Returns: true if the message has been removed
/** * Indicates whether this event is the result of an explicit * expunge by this client, or due to an expunge from external * sources. If <code>true</code>, this event is due to an * explicit expunge and hence all remaining messages in this * folder have been renumbered. If <code>false</code>, this event * is due to an external expunge. <p> * * Note that this method is valid only if the type of this event * is <code>REMOVED</code> * * @return true if the message has been removed */
public boolean isRemoved() { return removed; }
Return the array of messages added or removed.
Returns:array of messages
/** * Return the array of messages added or removed. * @return array of messages */
public Message[] getMessages() { return msgs; }
Invokes the appropriate MessageCountListener method.
/** * Invokes the appropriate MessageCountListener method. */
@Override public void dispatch(Object listener) { if (type == ADDED) ((MessageCountListener)listener).messagesAdded(this); else // REMOVED ((MessageCountListener)listener).messagesRemoved(this); } }