/*
* Copyright 2005-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.ws.transport.mail.monitor;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.event.MessageCountAdapter;
import javax.mail.event.MessageCountEvent;
import javax.mail.event.MessageCountListener;
import org.springframework.util.Assert;
import com.sun.mail.imap.IMAPFolder;
/**
* Implementation of the {@link MonitoringStrategy} interface that uses the IMAP IDLE command for asynchronous message
* detection.
*
* <p><b>Note</b> that this implementation is only suitable for use with IMAP servers which support the IDLE command.
* Additionally, this strategy requires JavaMail version 1.4.1.
*
* @author Arjen Poutsma
* @since 1.5.0
*/
public class ImapIdleMonitoringStrategy extends AbstractMonitoringStrategy {
private MessageCountListener messageCountListener;
@Override
protected void waitForNewMessages(Folder folder) throws MessagingException, InterruptedException {
Assert.isInstanceOf(IMAPFolder.class, folder);
IMAPFolder imapFolder = (IMAPFolder) folder;
// retrieve unseen messages before we enter the blocking idle call
if (searchForNewMessages(folder).length > 0) {
return;
}
if (messageCountListener == null) {
createMessageCountListener();
}
folder.addMessageCountListener(messageCountListener);
try {
imapFolder.idle();
}
finally {
folder.removeMessageCountListener(messageCountListener);
}
}
private void createMessageCountListener() {
messageCountListener = new MessageCountAdapter() {
@Override
public void messagesAdded(MessageCountEvent e) {
Message[] messages = e.getMessages();
for (Message message : messages) {
try {
// this will return the flow to the idle call, above
message.getLineCount();
}
catch (MessagingException ex) {
// ignore
}
}
}
};
}
}