nnrpdutils.java

java高级使用教程 全书一共分六章

// NnrpdUtils - constants and static utilities for NNRP daemon
//
// Copyright (C) 1996 by Jef Poskanzer <[e-mail]>.  All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme.Nnrpd;

import java.io.*;
import java.util.*;
import java.net.*;
import Acme.Utils;
import Acme.Fmt;

/// Constants and static utilities for NNRP daemon.
// <P>
// <A HREF="/resources/classes/Acme/Nnrpd/NnrpdUtils.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>

public class NnrpdUtils
    {

    // Server identification.
    public static final String serverName = "Acme.Nnrpd";
    public static final String serverVersion = "v0.95 of 19dec96";
    public static final String serverUrl = "http://www.acme.com/java/software/Package-Acme.Nnrpd.html";

    /// The default port to listen on and connect to.
    public static final int DEFAULT_PORT = 119;

    /// The default size of the article cache, in bytes.
    public static final int DEFAULT_ACACHESIZE = 10000000;

    /// The default maximum-size article to cache, in bytes.
    public static final int DEFAULT_MAXARTSIZE = 100000;

    /// The default size of the overview cache, in entries.
    public static final int DEFAULT_OCACHESIZE = 50000;

    /// Idle timeout, in milliseconds.
    public static final long INT_IDLETIMEOUT = Utils.INT_MINUTE * 15;

    /// How often to check the list of newsgroups.
    public static final long INT_CHECKGROUPS = Utils.INT_MINUTE * 30;

    /// How often to check the list of newsgroup descriptions.
    public static final long INT_CHECKGROUPDESCS = Utils.INT_DAY;

    /// How often to check a group's overview data.
    public static final long INT_CHECKOVERVIEW = Utils.INT_DAY;


    // NNTP commands.

    public static final String CMD_ARTICLE = "ARTICLE";
    public static final String CMD_AUTHINFO = "AUTHINFO";
    public static final String CMD_BODY = "BODY";
    public static final String CMD_DATE = "DATE";
    public static final String CMD_GROUP = "GROUP";
    public static final String CMD_HEAD = "HEAD";
    public static final String CMD_HELP = "HELP";
    public static final String CMD_IHAVE = "IHAVE";
    public static final String CMD_LAST = "LAST";
    public static final String CMD_LIST = "LIST";
    public static final String CMD_LISTGROUP = "LISTGROUP";
    public static final String CMD_MODE = "MODE";
    public static final String CMD_NEWGROUPS = "NEWGROUPS";
    public static final String CMD_NEWNEWS = "NEWNEWS";
    public static final String CMD_NEXT = "NEXT";
    public static final String CMD_POST = "POST";
    public static final String CMD_QUIT = "QUIT";
    public static final String CMD_SLAVE = "SLAVE";
    public static final String CMD_STAT = "STAT";
    public static final String CMD_XGTITLE = "XGTITLE";
    public static final String CMD_XHDR = "XHDR";
    public static final String CMD_XMODE = "XMODE";
    public static final String CMD_XOVER = "XOVER";
    public static final String CMD_XREPLIC = "XREPLIC";
    public static final String CMD_XTHREAD = "XTHREAD";


    // Some common NNTP responses.

    public static final String RES_NOSUCHGROUP =
	"411 no such news group";
    public static final String RES_NOCURRGROUP =
	"412 no current newsgroup has been selected";
    public static final String RES_NOCURRARTICLE =
	"420 no current article has been selected";
    public static final String RES_NOSUCHARTICLENUM =
	"423 no such article number in this group";
    public static final String RES_NOSUCHARTICLE =
	"430 no such article found";
    public static final String RES_BADCOMMAND =
	"500 command not recognized";
    public static final String RES_UNIMPLEMENTED =
	"500 command not implemented";
    public static final String RES_SYNTAXERROR =
	"501 command syntax error";
    public static final String RES_PROGFAULT =
	"503 program fault - command not performed";


    /// Read text terminated by a "." on a line by itself.
    public static String readText( DataInputStream din ) throws IOException
	{
	StringBuffer buf = new StringBuffer();
	while ( true )
	    {
	    String line = din.readLine();
	    if ( line == null || line.equals( "." ) )
		break;
	    buf.append( line );
	    buf.append( '\n' );
	    }
	return buf.toString();
	}


    /// Convert from YYMMDD HHMMSS [GMT] format into Java time.
    public static long rfc977DateTime( String dateStr, String timeStr, boolean gmt, long def )
	{
	if ( dateStr.length() != 6 || timeStr.length() != 6 )
	    return def;
	try
	    {
	    // Extract values from the strings.
	    int year = Integer.parseInt( dateStr.substring( 0, 2 ) );
	    int month = Integer.parseInt( dateStr.substring( 2, 4 ) );
	    int day = Integer.parseInt( dateStr.substring( 4, 6 ) );
	    int hour = Integer.parseInt( timeStr.substring( 0, 2 ) );
	    int minute = Integer.parseInt( timeStr.substring( 2, 4 ) );
	    int second = Integer.parseInt( timeStr.substring( 4, 6 ) );
	    // Adjust to Date representations.
	    if ( year < 50 )
		year += 100;
	    --month;
	    // And turn to a long.
	    if ( gmt )
		return Date.UTC( year, month, day, hour, minute, second );
	    else
		{
		Date date = new Date( year, month, day, hour, minute, second );
		return date.getTime();
		}
	    }
	catch ( Exception e )
	    {
	    return def;
	    }
	}
    
    /// Convert from Java time into YYMMDD MMHHSS GMT format.
    public static String rfc977DateTime( long time )
	{
	Date date = new Date( time );
	String gmtStr = date.toGMTString();
	String[] strArr = Utils.splitStr( gmtStr );
	int day = Integer.parseInt( strArr[0] );
	String months = "JanFebMarAprMayJunJulAugSepOctNovDec";
	int month = months.indexOf( strArr[1] ) / 3 + 1;
	int year = Integer.parseInt( strArr[2] ) - 1900;
	if ( year >= 100 )
	    year -= 100;
	int hour = Integer.parseInt( strArr[3].substring( 0, 2 ) );
	int minute = Integer.parseInt( strArr[3].substring( 3, 5 ) );
	int second = Integer.parseInt( strArr[3].substring( 6, 8 ) );
	return
	    Fmt.fmt( year, 2, Fmt.ZF ) +
	    Fmt.fmt( month, 2, Fmt.ZF ) +
	    Fmt.fmt( day, 2, Fmt.ZF ) +
	    " " +
	    Fmt.fmt( hour, 2, Fmt.ZF ) +
	    Fmt.fmt( minute, 2, Fmt.ZF ) +
	    Fmt.fmt( second, 2, Fmt.ZF ) +
	    " GMT";
	}

    }