jakarta.mail.event.MessageCountEvent Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.mail.event;
import java.util.*;
import jakarta.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
* {@link jakarta.mail.Folder#getMessageCount getMessageCount} or
* {@link jakarta.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 */
public static final int ADDED = 1;
/** The messages were removed from their folder */
public static final int REMOVED = 2;
/**
* 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
*/
protected boolean removed;
/**
* The messages.
*/
transient protected Message[] msgs;
private static final long serialVersionUID = -7447022340837897369L;
/**
* 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.
* @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
*
* @return true if the message has been removed
*/
public boolean isRemoved() {
return removed;
}
/**
* Return the array of messages added or removed.
* @return array of messages
*/
public Message[] getMessages() {
return msgs;
}
/**
* Invokes the appropriate MessageCountListener method.
*/
@Override
public void dispatch(Object listener) {
if (type == ADDED)
((MessageCountListener)listener).messagesAdded(this);
else // REMOVED
((MessageCountListener)listener).messagesRemoved(this);
}
}