org.xwiki.mail.internal.DefaultMailSender.java Source code

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Here is the source code for org.xwiki.mail.internal.DefaultMailSender.java

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/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.mail.internal;

import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentLinkedQueue;

import javax.inject.Inject;
import javax.inject.Singleton;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

import org.apache.commons.lang3.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.xwiki.component.annotation.Component;
import org.xwiki.component.phase.Initializable;
import org.xwiki.component.phase.InitializationException;
import org.xwiki.mail.MailResultListener;
import org.xwiki.mail.MailSender;
import org.xwiki.mail.MailSenderConfiguration;

/**
 * Default implementation using the {@link org.xwiki.mail.internal.DefaultMailSenderThread} to send emails
 * asynchronously.
 *
 * @version $Id: 9fd3bd6b56e034fc8d08935e7ec40564fdbd6a1c $
 * @since 6.1M2
 */
@Component
@Singleton
public class DefaultMailSender implements MailSender, Initializable {
    @Inject
    private MailSenderThread mailSenderThread;

    @Inject
    private MailSenderConfiguration configuration;

    @Inject
    private Logger logger;

    /**
     * The Mail queue that the mail sender thread will use to send mails. We use a separate thread to allow sending
     * mail asynchronously.
     */
    private Queue<MailSenderQueueItem> mailQueue = new ConcurrentLinkedQueue<>();

    @Override
    public void initialize() throws InitializationException {
        this.mailSenderThread.setName("Mail Sender Thread");
        this.mailSenderThread.startProcessing(getMailQueue());
    }

    @Override
    public void send(MimeMessage message, Session session) throws MessagingException {
        DefaultMailResultListener listener = new DefaultMailResultListener();
        sendAsynchronously(message, session, listener);
        waitTillSent(Long.MAX_VALUE);
        BlockingQueue<Exception> errorQueue = listener.getExceptionQueue();
        if (!errorQueue.isEmpty()) {
            throw new MessagingException(String.format("Failed to send mail message [%s]", message),
                    errorQueue.peek());
        }
    }

    @Override
    public void sendAsynchronously(MimeMessage message, Session session, MailResultListener listener) {
        try {
            // Perform some basic verification to avoid NPEs in JavaMail
            if (message.getFrom() == null) {
                // Try using the From address in the Session
                String from = this.configuration.getFromAddress();
                if (from != null) {
                    message.setFrom(new InternetAddress(from));
                } else {
                    throw new MessagingException("Missing the From Address for sending the mail. "
                            + "You need to either define it in the Mail Configuration or pass it in your message.");
                }
            }

            // Push new mail message on the queue
            getMailQueue().add(new MailSenderQueueItem(message, session, listener));
        } catch (Exception e) {
            // Save any exception in the listener
            listener.onError(message, e);
        }
    }

    /**
     * @return the mail queue containing all pending mails to be sent
     */
    public Queue<MailSenderQueueItem> getMailQueue() {
        return this.mailQueue;
    }

    @Override
    public void waitTillSent(long timeout) {
        long startTime = System.currentTimeMillis();
        while (hasMailQueueItemForCurrentThread() && System.currentTimeMillis() - startTime < timeout) {
            try {
                Thread.sleep(100L);
            } catch (InterruptedException e) {
                // Ignore but consider that the mail was sent
                this.logger.warn("Interrupted while waiting for mail to be sent. Reason [{}]",
                        ExceptionUtils.getRootCauseMessage(e));
                break;
            }
        }
    }

    private boolean hasMailQueueItemForCurrentThread() {
        Iterator<MailSenderQueueItem> iterator = getMailQueue().iterator();
        while (iterator.hasNext()) {
            MailSenderQueueItem item = iterator.next();
            if (Thread.currentThread().getId() == item.getThreadId()) {
                return true;
            }
        }
        return false;
    }

    /**
     * Stops the sending thread. Should be called when the application is stopped for a clean shutdown.
     * @throws InterruptedException if the thread failed to be stopped
     */
    public void stopMailSenderThread() throws InterruptedException {
        this.mailSenderThread.stopProcessing();
        // Wait till the thread goes away
        this.mailSenderThread.join();
    }
}