nntphandler.java

邮件服务器系统 支持SMTP POP3 是著名的Apache写 有一定的参考价值

/***********************************************************************
 * 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.                      *
 ***********************************************************************/

package org.apache.james.nntpserver;

import org.apache.avalon.cornerstone.services.connection.ConnectionHandler;
import org.apache.avalon.excalibur.pool.Poolable;
import org.apache.avalon.framework.activity.Disposable;
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.logger.AbstractLogEnabled;
import org.apache.avalon.framework.logger.Logger;
import org.apache.james.core.MailHeaders;
import org.apache.james.nntpserver.repository.NNTPArticle;
import org.apache.james.nntpserver.repository.NNTPGroup;
import org.apache.james.nntpserver.repository.NNTPRepository;
import org.apache.james.services.UsersRepository;
import org.apache.james.services.UsersStore;
import org.apache.james.util.CharTerminatedInputStream;
import org.apache.james.util.DotStuffingInputStream;
import org.apache.james.util.ExtraDotOutputStream;
import org.apache.james.util.InternetPrintWriter;
import org.apache.james.util.RFC977DateFormat;
import org.apache.james.util.RFC2980DateFormat;
import org.apache.james.util.SimplifiedDateFormat;
import org.apache.james.util.watchdog.Watchdog;
import org.apache.james.util.watchdog.WatchdogTarget;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.SequenceInputStream;
import java.net.Socket;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.StringTokenizer;
import javax.mail.MessagingException;

/**
 * The NNTP protocol is defined by RFC 977.
 * This implementation is based on IETF draft 15, posted on 15th July '2002.
 * URL: http://www.ietf.org/internet-drafts/draft-ietf-nntpext-base-15.txt
 *
 * Common NNTP extensions are in RFC 2980.
 */
public class NNTPHandler
    extends AbstractLogEnabled
    implements ConnectionHandler, Poolable {

    /**
     * used to calculate DATE from - see 11.3
     */
    private static final SimplifiedDateFormat DF_RFC977 = new RFC977DateFormat();

    /**
     * Date format for the DATE keyword - see 11.1.1
     */
    private static final SimplifiedDateFormat DF_RFC2980 = new RFC2980DateFormat();

    /**
     * The UTC offset for this time zone.
     */
    public static final long UTC_OFFSET = Calendar.getInstance().get(Calendar.ZONE_OFFSET);

    /**
     * The text string for the NNTP MODE command.
     */
    private final static String COMMAND_MODE = "MODE";

    /**
     * The text string for the NNTP LIST command.
     */
    private final static String COMMAND_LIST = "LIST";

    /**
     * The text string for the NNTP GROUP command.
     */
    private final static String COMMAND_GROUP = "GROUP";

    /**
     * The text string for the NNTP NEXT command.
     */
    private final static String COMMAND_NEXT = "NEXT";

    /**
     * The text string for the NNTP LAST command.
     */
    private final static String COMMAND_LAST = "LAST";

    /**
     * The text string for the NNTP ARTICLE command.
     */
    private final static String COMMAND_ARTICLE = "ARTICLE";

    /**
     * The text string for the NNTP HEAD command.
     */
    private final static String COMMAND_HEAD = "HEAD";

    /**
     * The text string for the NNTP BODY command.
     */
    private final static String COMMAND_BODY = "BODY";

    /**
     * The text string for the NNTP STAT command.
     */
    private final static String COMMAND_STAT = "STAT";

    /**
     * The text string for the NNTP POST command.
     */
    private final static String COMMAND_POST = "POST";

    /**
     * The text string for the NNTP IHAVE command.
     */
    private final static String COMMAND_IHAVE = "IHAVE";

    /**
     * The text string for the NNTP QUIT command.
     */
    private final static String COMMAND_QUIT = "QUIT";

    /**
     * The text string for the NNTP SLAVE command.
     */
    private final static String COMMAND_SLAVE = "SLAVE";

    /**
     * The text string for the NNTP DATE command.
     */
    private final static String COMMAND_DATE = "DATE";

    /**
     * The text string for the NNTP HELP command.
     */
    private final static String COMMAND_HELP = "HELP";

    /**
     * The text string for the NNTP NEWGROUPS command.
     */
    private final static String COMMAND_NEWGROUPS = "NEWGROUPS";

    /**
     * The text string for the NNTP NEWNEWS command.
     */
    private final static String COMMAND_NEWNEWS = "NEWNEWS";

    /**
     * The text string for the NNTP LISTGROUP command.
     */
    private final static String COMMAND_LISTGROUP = "LISTGROUP";

    /**
     * The text string for the NNTP OVER command.
     */
    private final static String COMMAND_OVER = "OVER";

    /**
     * The text string for the NNTP XOVER command.
     */
    private final static String COMMAND_XOVER = "XOVER";

    /**
     * The text string for the NNTP HDR command.
     */
    private final static String COMMAND_HDR = "HDR";

    /**
     * The text string for the NNTP XHDR command.
     */
    private final static String COMMAND_XHDR = "XHDR";

    /**
     * The text string for the NNTP AUTHINFO command.
     */
    private final static String COMMAND_AUTHINFO = "AUTHINFO";

    /**
     * The text string for the NNTP PAT command.
     */
    private final static String COMMAND_PAT = "PAT";

    /**
     * The text string for the NNTP MODE READER parameter.
     */
    private final static String MODE_TYPE_READER = "READER";

    /**
     * The text string for the NNTP MODE STREAM parameter.
     */
    private final static String MODE_TYPE_STREAM = "STREAM";

    /**
     * The text string for the NNTP AUTHINFO USER parameter.
     */
    private final static String AUTHINFO_PARAM_USER = "USER";

    /**
     * The text string for the NNTP AUTHINFO PASS parameter.
     */
    private final static String AUTHINFO_PARAM_PASS = "PASS";

    /**
     * The character array that indicates termination of an NNTP message
     */
    private final static char[] NNTPTerminator = { '\r', '\n', '.', '\r', '\n' };

    /**
     * The thread executing this handler 
     */
    private Thread handlerThread;

    /**
     * The remote host name obtained by lookup on the socket.
     */
    private String remoteHost;

    /**
     * The remote IP address of the socket.
     */
    private String remoteIP;

    /**
     * The TCP/IP socket over which the POP3 interaction
     * is occurring
     */
    private Socket socket;

    /**
     * The incoming stream of bytes coming from the socket.
     */
    private InputStream in;

    /**
     * The reader associated with incoming characters.
     */
    private BufferedReader reader;

    /**
     * The socket's output stream
     */
    private OutputStream outs;

    /**
     * The writer to which outgoing messages are written.
     */
    private PrintWriter writer;

    /**
     * The current newsgroup.
     */
    private NNTPGroup group;

    /**
     * The current newsgroup.
     */
    private int currentArticleNumber = -1;

    /**
     * Per-service configuration data that applies to all handlers
     * associated with the service.
     */
    private NNTPHandlerConfigurationData theConfigData;

    /**
     * The user id associated with the NNTP dialogue
     */
    private String user = null;

    /**
     * The password associated with the NNTP dialogue
     */
    private String password = null;

    /**
     * Whether the user for this session has already authenticated.
     * Used to optimize authentication checks
     */
    boolean isAlreadyAuthenticated = false;

    /**
     * The watchdog being used by this handler to deal with idle timeouts.
     */
    private Watchdog theWatchdog;

    /**
     * The watchdog target that idles out this handler.
     */
    private WatchdogTarget theWatchdogTarget = new NNTPWatchdogTarget();

    /**
     * Set the configuration data for the handler
     *
     * @param theData configuration data for the handler
     */
    void setConfigurationData(NNTPHandlerConfigurationData theData) {
        theConfigData = theData;
    }

    /**
     * Set the Watchdog for use by this handler.
     *
     * @param theWatchdog the watchdog
     */
    void setWatchdog(Watchdog theWatchdog) {
        this.theWatchdog = theWatchdog;
    }

    /**
     * Gets the Watchdog Target that should be used by Watchdogs managing
     * this connection.
     *
     * @return the WatchdogTarget
     */
    WatchdogTarget getWatchdogTarget() {
        return theWatchdogTarget;
    }

    /**
     * Idle out this connection
     */