javamailgateway.java

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/**
 * $RCSfile: JavaMailGateway.java,v $
 * $Revision: 1.9 $
 * $Date: 2002/08/08 18:52:45 $
 *
 * Copyright (C) 1999-2002 CoolServlets, Inc. All Rights Reserved.
 *
 * This software is the proprietary information of CoolServlets, Inc.
 * Use is subject to license terms.
 */

package com.jivesoftware.forum.gateway;

import java.io.*;
import java.util.*;
import java.text.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.mail.internet.ParseException;
import javax.activation.*;
import com.jivesoftware.forum.*;
import com.jivesoftware.forum.database.DbForumFactory;
import com.jivesoftware.util.StringUtils;
import com.sun.mail.util.BEncoderStream;
import com.sun.mail.util.QEncoderStream;

/**
 * This class is an abstract JavaMail implementation of the Gateway
 * interface. This class provides all the needed methods to import messages
 * from whatever JavaMail providers are supported.<p>
 *
 * If a provider such as a NNTP provider needs to do something special when
 * connecting or retrieving messages all it needs to do is re-implement
 * the method in question in a subclass.<p>
 *
 * @author Bruce Ritchie
 */
public abstract class JavaMailGateway implements GatewayImporter {

    /**
     * Protocol to be used by the JavaMail store mechanism.
     */
    protected String protocol = "";

    /**
     * Mailbox to be used by the JavaMail store mechanism.
     */
    protected String mailbox = "";

    /**
     * The host that is running the  server daemon.
     */
    protected String host = "";

    /**
     * The port that the server daemon is listening to.
     */
    protected int port = -1;

    /**
     * The username to use to connect to the server deamon.
     */
    protected String username = null;

    /**
     * The password to use to connect to the server deamon.
     */
    protected String password = null;

    /**
     * Flag used to determine if we should delete messages
     * from the server or not.
     */
    protected boolean deleteEnabled = false;

    /**
     * Flag used to determine if the JavaMail provider a
     * gateways uses should be put into debug mode or not.
     */
    protected boolean debugEnabled = false;

    /**
     * Flag used to determine if attachments are handled or not.
     */
    protected boolean attachmentsEnabled = false;

    /**
     * Flag used to stop an already running import or export.
     */
    protected boolean stopFlag = false;

    // Date parsers that are used when JavaMail fails to parse a date.
    // Not thread safe btw.
    private SimpleDateFormat format1;
    private SimpleDateFormat format2;
    private SimpleDateFormat format3;
    private SimpleDateFormat format4;
    private SimpleDateFormat format5;
    private SimpleDateFormat format6;

    /**
     * Used to flag messages in the forum with a message id.
     */
    protected String gatewayMessageId = "Message-ID";

    /**
     * Used to flag messages in the forum with a parent id.
     */
    protected String gatewayParentId = "Parent-ID";

    /**
     * Prefix to search for to determine replying messages (lowercase).
     */
    protected String replyPrefix = "re:";

    /**
     * Whether or not to attempt to determin parentage via subject line matching
     */
    protected boolean subjectParentageCheckEnabled = true;

    /**
     * Dummy message string for messages autocreated by this gateway
     */
    protected String temporaryParentBody = " ";

    /**
     * Used to store the parent message id's indexed by message id
     */
    protected Hashtable parentMessageIDs = new Hashtable();

    /**
     * Used to store a messages original date if the date had to be changed
     * such as in the case of a parent with an older child
     */
    public static final String MESSAGE_DATE_HEADER = "Message-Original-Date";

    /**
     * Used for storing a hash of a subject as an extended property
     * needed for parent message comparison
     */
    public static final String SUBJECT_EXTENDED_PROPERTY = "Subject-Hash";

    /**
     * Used to mark a message as a Jive created message
     */
    public static final String DUMMY_PARENT_HEADER = "Jive-Created-Message";

    /**
     * The forumID is used instead of an actual forum object since
     * Jive's cache system will orphan the forum object after 6
     * hours. Since gateways are usually created once and not
     * destroyed after every use, we mustn't hang onto a forum object
     * for too long.
     */
    protected long forumID;

    protected ForumFactory factory;


    public JavaMailGateway(ForumFactory factory, Forum forum) {
        this.factory = factory;
        this.forumID = forum.getID();
        parentMessageIDs = new Hashtable();
    }

    public synchronized void importData(Date afterDate) throws GatewayException
    {
        // Check to make sure that all required properties are set.
        if (host.equals("") || port == -1 || protocol.equals("") ||
                mailbox.equals(""))
        {
            throw new GatewayException("Required properties are not all set.");
        }

        Store store   = null;
        Folder folder = null;

        try {
            store  = getStore(afterDate);
            folder = getFolder(store);
            retrieveMessages(store, folder, afterDate);
        }
        catch (MessagingException e) {
            throw new GatewayException(e);
        }
        finally {
            try { folder.close(deleteEnabled); }
            catch (Exception e) { System.err.println("Unable to close folder"); }
            try { store.close(); }
            catch (Exception e) { System.err.println("Unable to close store"); }
        }

        cleanup();
        parentMessageIDs.clear();
    }

    /**
     * Retrieve the JavaMail store.
     *
     * @param afterDate the date after which messages will be imported.
     * @throws MessagingException if an error occurred establishing the connection.
     * @return a connected store object.
     */
    protected Store getStore(Date afterDate) throws MessagingException {
        Session session = Session.getInstance(System.getProperties(), null);

        // Turn on debugging if it's enabled.
        session.setDebug(debugEnabled);
        // Create a Store
        URLName url = new URLName(protocol, host, port, mailbox, username, password);
        Store store = session.getStore(url);
        // Connect the store
        store.connect();

        return store;
    }

    /**
     * Retrieve the JavaMail folder from the provided store object.
     *
     * @param store the JavaMail store.
     * @return a connected folder object.
     * @throws MessagingException if an error occurred establishing the connection.
     */
    protected Folder getFolder(Store store) throws MessagingException {
        Folder folder;

        // Make sure that we can get the default folder.
        if ((folder = store.getFolder(mailbox)) == null) {
            throw new MessagingException("No folder found");
        }

        // Open the folder in the proper mode
        if (deleteEnabled) {
            folder.open(Folder.READ_WRITE);
        }
        else {
            folder.open(Folder.READ_ONLY);
        }

        return folder;
    }

    /**
     * Retrieve messages from a JavaMail folder and calls methods to
     * import them into a forum.
     *
     * @param folder a connected JavaMail folder object.
     * @param afterDate the date after which we'll import message.
     * @throws MessagingException if a protocol error occurs retrieving a message.
     * @throws GatewayException
     */
    protected void retrieveMessages(Store store, Folder folder, Date afterDate)
            throws MessagingException, GatewayException
    {
        int totalMsgCount = folder.getMessageCount();
        List messages     = new ArrayList(Math.min(50, totalMsgCount));

        try {
            for (int curMsgCount = 1; curMsgCount <= totalMsgCount && !stopFlag; curMsgCount++) {
                try {
                    // if the server disconnected us, reconnect
                    // maximum of 3 reconnect tries before we die
                    if (!folder.isOpen() || !store.isConnected()) {
                        System.err.println("Server has disconnected, reconnecting.");

                        try { folder.close(false); }
                        catch (Exception e) { /* ignore */ }
                        try { store.close(); }
                        catch (Exception e) { /* ignore */ }

                        int retry = 1;
                        while (!store.isConnected() && retry < 4) {
                            retry++;
                            store  = getStore(afterDate);
                            folder = getFolder(store);
                        }

                        // unsuccessful, die
                        if (!store.isConnected() && retry > 3) {
                            throw new GatewayException("Unable to connect to the" +
                                            " JavaMail store provider");
                        }
                    }

                    MimeMessage message = (MimeMessage) folder.getMessage(curMsgCount);
                    ForumMessage forumMessage = parseMessage(message, afterDate);

                    if (forumMessage == null) {
                        continue;
                    }

                    // check to see if the message is already in the db
                    // or whether it's a dummy parent message we've previously
                    // created
                    Forum forum            = factory.getForum(forumID);
                    String messageID       = getMessageID(message);
                    ForumMessage dbMessage = lookupMessageByID(forum, messageID, true);

                    if (dbMessage != null && !"true".equals(
                            dbMessage.getProperty(DUMMY_PARENT_HEADER)))
                    {
                        continue;
                    }

                    messages.add(forumMessage);

                    boolean hasAttachments = isMessageWithAttachments(message);

                    // insert into db every 50 messages or if the message
                    // has attachments
                    if (curMsgCount % 50 == 0 ||
                            (hasAttachments && attachmentsEnabled))
                    {
                        processMessagesAndImport(messages);

                        if (hasAttachments && attachmentsEnabled) {
                            // we need to retrieve the forumMessage from the
                            // db since the one we have isn't attached to a
                            // thread
                            forumMessage = lookupMessageByID(forum, messageID, false);

                            if (forumMessage != null) {
                                // If the message already has attachments, it means that the
                                // message has already been imported (and thus wasn't imported
                                // in the processMessagesAndImport(messages) method call above.
                                // Only add attachments if that isn't the case.
                                if (forumMessage.getAttachmentCount() < 1) {