mboxmailrepository.java

java 开发的邮件服务器平台。支持以下协议。 协议可以修改为自己的专门标识

/***********************************************************************
 * Copyright (c) 2000-2004 The Apache Software Foundation.             *
 * All rights reserved.                                                *
 * ------------------------------------------------------------------- *
 * 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.                      *
 ***********************************************************************/

/* TODO:
 *
 * 1. Currently, iterating through the message collection does not
 *    preserve the order in the file.  Change this with some form of
 *    OrderedMap.  There is a suitable class in Jakarta Commons
 *    Collections.
 *
 * 2. Optimize the remove operation.
 *
 * 3. Don't load entire message into memory.  This would mean computing
 *    the hash during I/O streaming, rather than loading entire message
 *    into memory, and using a MimeMessageWrapper with a suitable data
 *    source.  As a strawman, the interface to MessageAction would
 *    carry the hash, along with a size-limited stream providing the
 *    message body.
 *
 * 4. Decide what to do when there are IDENTICAL messages in the file.
 *    Right now only the last one will ever be processed, due to key
 *    collissions.
 *
 * 5. isComplete()  - DONE.
 *
 * 6. Buffered I/O. - Partially done, and optional.
 *
 */


package org.apache.james.mailrepository;

import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.james.core.MailImpl;
import org.apache.james.services.MailRepository;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.Perl5Matcher;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.InternetAddress;
import java.util.*;
import java.io.*;
import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import java.text.SimpleDateFormat;
import java.lang.reflect.Array;

/**
 * Implementation of a MailRepository using UNIX mbox files.
 *
 * <p>Requires a configuration element in the .conf.xml file of the form:
 *  <br>&lt;repository destinationURL="mbox://&lt;directory&gt;"
 *  <br>            type="MAIL"
 *  <br>&lt;/directory&gt; is where the individual mbox files are read from/written to
 * <br>Type can ONLY be MAIL (SPOOL is NOT supported)
 *
 * <p>Requires a logger called MailRepository.
 *
 * <p> Implementation notes:
 * <p>
 * This class keeps an internal store of the mbox file
 * When the internal mbox file is updated (added/deleted)
 * then the file will be re-read from disk and then written back.
 * This is a bit inefficent but means that the file on disk
 * should be correct.
 * <p>
 * The mbox store is mainly meant to be used as a one-way street.
 * Storing new emails is very fast (append to file) whereas reading them (via POP3) is
 * slower (read from disk and parse).
 * Therefore this implementation is best suited to people who wish to use the mbox format
 * for taking data out of James and into something else (IMAP server or mail list displayer)
 *
 * @version CVS $Revision: 1.1.2.5 $
 */


public class MBoxMailRepository
        extends AbstractLogEnabled
            implements MailRepository, Component, Contextualizable, Composable, Configurable, Initializable {


    static final SimpleDateFormat dy = new SimpleDateFormat("EE MMM dd HH:mm:ss yyyy", Locale.US);
    static final String LOCKEXT = ".lock";
    static final String WORKEXT = ".work";
    static final int LOCKSLEEPDELAY = 2000; // 2 second back off in the event of a problem with the lock file
    static final int MAXSLEEPTIMES = 100; //
    static final long MLISTPRESIZEFACTOR = 10 * 1024;  // The hash table will be loaded with a initial capacity of  filelength/MLISTPRESIZEFACTOR
    static final long DEFAULTMLISTCAPACITY = 20; // Set up a hashtable to have a meaningful default

    /**
     * Whether line buffering is turned used.
     */
    private static boolean BUFFERING = true;

    /**
     * Whether 'deep debugging' is turned on.
     */
    private static final boolean DEEP_DEBUG = true;

    /**
     * The Avalon context used by the instance
     */
    private Context context;

    /**
     * The internal list of the emails
     * The key is an adapted MD5 checksum of the mail
     */
    private Hashtable mList = null;
    /**
     * The filename to read & write the mbox from/to
     */
    private String mboxFile;

    /**
     * A callback used when a message is read from the mbox file
     */
    public interface MessageAction {
        public boolean isComplete();  // *** Not valid until AFTER each call to messageAction(...)!
        public MimeMessage messageAction(String messageSeparator, String bodyText, long messageStart);
    }


    /**
     * Convert a MimeMessage into raw text
     * @param mc The mime message to convert
     * @return A string representation of the mime message
     * @throws IOException
     * @throws MessagingException
     */
    private String getRawMessage(MimeMessage mc) throws IOException, MessagingException {

        ByteArrayOutputStream rawMessage = new ByteArrayOutputStream();
        mc.writeTo(rawMessage);
        return rawMessage.toString();
    }

    /**
     * Parse a text block as an email and convert it into a mime message
     * @param emailBody The headers and body of an email. This will be parsed into a mime message and stored
     */
    private MimeMessage convertTextToMimeMessage(String emailBody) {
        //this.emailBody = emailBody;
        MimeMessage mimeMessage = null;
        // Parse the mime message as we have the full message now (in string format)
        ByteArrayInputStream mb = new ByteArrayInputStream(emailBody.getBytes());
        Properties props = System.getProperties();
        Session session = Session.getDefaultInstance(props);
        String toAddr = null;
        try {
            mimeMessage = new MimeMessage(session, mb);


        } catch (MessagingException e) {
            getLogger().error("Unable to parse mime message!", e);
        }

        if (mimeMessage == null && getLogger().isDebugEnabled()) {
            StringBuffer logBuffer =
                    new StringBuffer(128)
                    .append(this.getClass().getName())
                    .append(" Mime message is null");
            getLogger().debug(logBuffer.toString());
        }

        /*
        try {
            // Attempt to read the TO field and see if it errors
            toAddr = mimeMessage.getRecipients(javax.mail.Message.RecipientType.TO).toString();
        } catch (Exception e) {
            // It has errored, so time for plan B
            // use the from field I suppose
            try {
                mimeMessage.setRecipients(javax.mail.Message.RecipientType.TO, mimeMessage.getFrom());
                if (getLogger().isDebugEnabled()) {
                    StringBuffer logBuffer =
                            new StringBuffer(128)
                            .append(this.getClass().getName())
                            .append(" Patching To: field for message ")
                            .append(" with  From: field");
                    getLogger().debug(logBuffer.toString());
                }
            } catch (MessagingException e1) {
                getLogger().error("Unable to set to: field to from: field", e);
            }
        } */
        return mimeMessage;
    }

    /**
     * Generate a hex representation of an MD5 checksum on the emailbody
     * @param emailBody
     * @return A hex representation of the text
     * @throws NoSuchAlgorithmException
     */
    private String generateKeyValue(String emailBody) throws NoSuchAlgorithmException {
        // MD5 the email body for a reilable (ha ha) key
        byte[] digArray = MessageDigest.getInstance("MD5").digest(emailBody.getBytes());
        StringBuffer digest = new StringBuffer();
        for (int i = 0; i < digArray.length; i++) {
            digest.append(Integer.toString(digArray[i], Character.MAX_RADIX).toUpperCase());
        }
        return digest.toString();
    }

    /**
     * Parse the mbox file.
     * @param ins The random access file to load. Note that the file may or may not start at offset 0 in the file
     * @param messAct The action to take when a message is found
     */
    private MimeMessage parseMboxFile(RandomAccessFile ins, MessageAction messAct) {
        if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
            StringBuffer logBuffer =
                    new StringBuffer(128)
                    .append(this.getClass().getName())
                    .append(" Start parsing ")
                    .append(mboxFile);

            getLogger().debug(logBuffer.toString());
        }
        try {

            Perl5Compiler sepMatchCompiler = new Perl5Compiler();
            Pattern sepMatchPattern = sepMatchCompiler.compile("^From (.*) (.*):(.*):(.*)$");
            Perl5Matcher sepMatch = new Perl5Matcher();

            int c;
            boolean inMessage = false;
            StringBuffer messageBuffer = new StringBuffer();
            String previousMessageSeparator = null;
            boolean foundSep = false;

            long prevMessageStart = ins.getFilePointer();
            if (BUFFERING) {
            String line = null;
            while ((line = ins.readLine()) != null) {
                foundSep = sepMatch.contains(line + "\n", sepMatchPattern);

                if (foundSep && inMessage) {
//                    if ((DEEP_DEBUG) && (getLogger().isDebugEnabled())) {
//                        getLogger().debug(this.getClass().getName() + " Invoking " + messAct.getClass() + " at " + prevMessageStart);
//                    }
                    MimeMessage endResult = messAct.messageAction(previousMessageSeparator, messageBuffer.toString(), prevMessageStart);
                    if (messAct.isComplete()) {
                        // I've got what I want so just exit
                        return endResult;
                    }
                    previousMessageSeparator = line;
                    prevMessageStart = ins.getFilePointer() - line.length();
                    messageBuffer = new StringBuffer();
                    inMessage = true;
                }
                // Only done at the start (first header)
                if (foundSep && !inMessage) {
                    previousMessageSeparator = line.toString();
                    inMessage = true;
                }
                if (!foundSep && inMessage) {
                    messageBuffer.append(line).append("\n");