httpdate.java

一个简单的visio程序。

package servlet.http;

import java.io.IOException;
import java.io.OutputStream;
import servlet.util.Ascii;

// Referenced classes of package servlet.http:
//            HttpDateUpdater

public class HttpDate extends Ascii
{

    public HttpDate(long l)
    {
        setTime(l);
    }

    public HttpDate()
    {
    }

    public void parse(byte abyte0[], int i, int j)
    {
        try
        {
            int k = i + j;
            i = parseDay(abyte0, i);
            byte byte0;
            while(Ascii.isWhite(byte0 = abyte0[i++])) ;
            if(Ascii.isDigit(byte0))
            {
                int l;
                for(l = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); l = (l * 10 + byte0) - 48);
                mday = l;
                if(Ascii.isWhite(byte0))
                    while(Ascii.isWhite(byte0 = abyte0[i++])) ;
                else
                if(byte0 == 45)
                    byte0 = abyte0[i++];
                else
                    throw new IllegalArgumentException();
                i = parseMonth(byte0, abyte0, i);
                if(Ascii.isWhite(byte0 = abyte0[i++]))
                    while(Ascii.isWhite(byte0 = abyte0[i++])) ;
                else
                if(byte0 == 45)
                    byte0 = abyte0[i++];
                else
                    throw new IllegalArgumentException();
                if(!Ascii.isDigit(byte0))
                    throw new IllegalArgumentException();
                for(l = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); l = (l * 10 + byte0) - 48);
                if(l < 100)
                    l += 1900;
                if(mday > daysInMonth(mon, l))
                    throw new IllegalArgumentException();
                year = l - 1900;
                i = parseTime(abyte0, i);
                while(Ascii.isWhite(byte0 = abyte0[i++])) ;
                if(Ascii.toLower(byte0) != 103 || Ascii.toLower(abyte0[i++]) != 109 || Ascii.toLower(abyte0[i++]) != 116)
                    throw new IllegalArgumentException();
            }
            else
            {
                i = parseMonth(byte0, abyte0, i);
                if(!Ascii.isWhite(byte0 = abyte0[i++]))
                    throw new IllegalArgumentException();
                while(Ascii.isWhite(byte0 = abyte0[i++])) ;
                if(!Ascii.isDigit(byte0))
                    throw new IllegalArgumentException();
                int i1;
                for(i1 = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); i1 = (i1 * 10 + byte0) - 48);
                mday = i1;
                i = parseTime(abyte0, i);
                while(Ascii.isWhite(byte0 = abyte0[i++])) ;
                for(i1 = byte0 - 48; i < k && Ascii.isDigit(byte0 = abyte0[i++]); i1 = (i1 * 10 + byte0) - 48);
                if(i1 < 1900 || mday > daysInMonth(mon, i1))
                    throw new IllegalArgumentException();
                year = i1 - 1900;
            }
            return;
        }
        catch(ArrayIndexOutOfBoundsException ex)
        {
            throw new IllegalArgumentException();
        }
    }

    public void parse(String s)
    {
        byte abyte0[] = toBytes(s);
        parse(abyte0, 0, abyte0.length);
    }

    private int parseDay(byte abyte0[], int i)
    {
        byte byte0;
        while(Ascii.isWhite(byte0 = abyte0[i++])) ;
        int j = Ascii.toLower(byte0);
        j = j << 8 | Ascii.toLower(abyte0[i++]);
        j = j << 8 | Ascii.toLower(abyte0[i++]);
        switch(j)
        {
        case 7566702: 
            wday = 0;
            break;

        case 7171950: 
            wday = 1;
            break;

        case 7632229: 
            wday = 2;
            break;

        case 7824740: 
            wday = 3;
            break;

        case 7628917: 
            wday = 4;
            break;

        case 6713961: 
            wday = 5;
            break;

        case 7561588: 
            wday = 6;
            break;

        default:
            throw new IllegalArgumentException();

        }
        if(Ascii.isAlpha(byte0 = abyte0[i++]))
        {
            byte abyte1[] = days[wday];
            int k = abyte1.length;
            for(int l = 3; l < k; l++)
            {
                if(Ascii.toLower(byte0) != abyte1[l])
                    throw new IllegalArgumentException();
                byte0 = abyte0[i++];
            }

        }
        if(!Ascii.isWhite(byte0) && byte0 != 44)
            throw new IllegalArgumentException();
        else
            return i;
    }

    private int parseMonth(int i, byte abyte0[], int j)
    {
        int k = Ascii.toLower(i);
        k = k << 8 | Ascii.toLower(abyte0[j++]);
        k = k << 8 | Ascii.toLower(abyte0[j++]);
        switch(k)
        {
        case 6971758: 
            mon = 0;
            break;

        case 6710626: 
            mon = 1;
            break;

        case 7168370: 
            mon = 2;
            break;

        case 6385778: 
            mon = 3;
            break;

        case 7168377: 
            mon = 4;
            break;

        case 6976878: 
            mon = 5;
            break;

        case 6976876: 
            mon = 6;
            break;

        case 6387047: 
            mon = 7;
            break;

        case 7562608: 
            mon = 8;
            break;

        case 7299956: 
            mon = 9;
            break;

        case 7237494: 
            mon = 10;
            break;

        case 6579555: 
            mon = 11;
            break;

        default:
            throw new IllegalArgumentException();

        }
        return j;
    }

    private int parseTime(byte abyte0[], int i)
    {
        byte byte0;
        while(Ascii.isWhite(byte0 = abyte0[i++])) ;
        if(Ascii.isDigit(byte0))
        {
            int j;
            for(j = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); j = (j * 10 + byte0) - 48);
            if(j < 24 && byte0 == 58 && Ascii.isDigit(byte0 = abyte0[i++]))
            {
                hour = j;
                for(j = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); j = (j * 10 + byte0) - 48);
                if(j < 60 && byte0 == 58 && Ascii.isDigit(byte0 = abyte0[i++]))
                {
                    min = j;
                    for(j = byte0 - 48; Ascii.isDigit(byte0 = abyte0[i++]); j = (j * 10 + byte0) - 48);
                    if(j < 60 && byte0 == 32)
                    {
                        sec = j;
                        return i;
                    }
                }
            }
        }
        throw new IllegalArgumentException();
    }

    public void write(OutputStream outputstream)
        throws IOException
    {
        byte abyte0[] = new byte[DATELEN];
        outputstream.write(abyte0, 0, getBytes(abyte0, 0, abyte0.length));
    }

    public String toString()
    {
        byte abyte0[] = new byte[DATELEN];
        return new String(abyte0, 0, 0, getBytes(abyte0, 0, abyte0.length));
    }

    public int getBytes(byte abyte0[], int i, int j)
    {
        if(j < DATELEN)
        {
            throw new IllegalArgumentException("array too small");
        }
        else
        {
            byte abyte1[] = days[wday];
            abyte0[i++] = abyte1[0];
            abyte0[i++] = abyte1[1];
            abyte0[i++] = abyte1[2];
            abyte0[i++] = 44;
            abyte0[i++] = 32;
            abyte0[i++] = (byte)(48 + mday / 10);
            abyte0[i++] = (byte)(48 + mday % 10);
            abyte0[i++] = 32;
            abyte1 = months[mon];
            abyte0[i++] = abyte1[0];
            abyte0[i++] = abyte1[1];
            abyte0[i++] = abyte1[2];
            abyte0[i++] = 32;
            int k = year + 1900;
            abyte0[i++] = (byte)(48 + k / 1000);
            abyte0[i++] = (byte)(48 + (k %= 1000) / 100);
            abyte0[i++] = (byte)(48 + (k %= 100) / 10);
            abyte0[i++] = (byte)(48 + k % 10);
            abyte0[i++] = 32;
            abyte0[i++] = (byte)(48 + hour / 10);
            abyte0[i++] = (byte)(48 + hour % 10);
            abyte0[i++] = 58;
            abyte0[i++] = (byte)(48 + min / 10);
            abyte0[i++] = (byte)(48 + min % 10);
            abyte0[i++] = 58;
            abyte0[i++] = (byte)(48 + sec / 10);
            abyte0[i++] = (byte)(48 + sec % 10);
            abyte0[i++] = 32;
            abyte0[i++] = 71;
            abyte0[i++] = 77;
            abyte0[i] = 84;
            return DATELEN;
        }
    }

    public long getTime()
    {
        int i = year;
        int j = (i - 70) * DAYS_PER_YEAR;
        j += (i - 69) / 4;
        j -= (i - 1) / 100;
        j += (i + 299) / 400;
        j += (daysBeforeMonth(mon, i) + mday) - 1;
        return (sec + 60 * (min + 60 * (hour + 24 * j))) * 1000L;
    }

    public static long getCurrentTime()
    {
        return updater.get();
    }

    protected static boolean isLeapYear(int i)
    {
        return (i & 0x3) == 0 && (i % 100 != 0 || (i + 300) % 400 != 0);
    }

    protected static int daysInMonth(int i, int j)
    {
        if(isLeapYear(j))
            return daysInMonthLeap[i];
        else
            return daysInMonth[i];
    }

    protected static int daysBeforeMonth(int i, int j)
    {
        if(isLeapYear(j))
            return daysBeforeMonthLeap[i];
        else
            return daysBeforeMonth[i];
    }

    public void setTime(long l)
    {
        int i = (int)(l / 1000L);
        int j = i / SECS_PER_DAY;
        i -= j * SECS_PER_DAY;
        hour = i / SECS_PER_HOUR;
        i -= hour * SECS_PER_HOUR;
        min = i / SECS_PER_MIN;
        sec = i - min * SECS_PER_MIN;
        wday = (j + BASE_DAY_OF_WEEK) % 7;
        int k = j / DAYS_PER_LEAP;
        j -= k * DAYS_PER_LEAP;
        boolean flag = false;
        int i1 = k * 4 + 70;
        if(j >= DAYS_PER_YEAR)
        {
            i1++;
            j -= DAYS_PER_YEAR;
            if(j >= DAYS_PER_YEAR)
            {
                i1++;
                j -= DAYS_PER_YEAR;
                if(j >= DAYS_PER_YEAR + 1)
                {
                    i1++;
                    j -= DAYS_PER_YEAR + 1;
                }
                else
                {
                    flag = true;
                }
            }
        }
        year = i1;
        short aword0[] = flag ? daysBeforeMonthLeap : daysBeforeMonth;
        int j1;
        for(j1 = 1; aword0[j1] <= j; j1++);
        mon = --j1;
        mday = (j - aword0[j1]) + 1;
    }

    public void setTime()
    {
        updater.get(this);
    }

    protected static byte[] toBytes(String s)
    {
        byte abyte0[] = new byte[s.length()];
        s.getBytes(0, abyte0.length, abyte0, 0);
        return abyte0;
    }

    protected int sec;
    protected int min;
    protected int hour;
    protected int mday;
    protected int mon;
    protected int year;
    protected int wday;
    protected static final byte days[][] = {
        toBytes("Sunday"), toBytes("Monday"), toBytes("Tuesday"), toBytes("Wednesday"), toBytes("Thursday"), toBytes("Friday"), toBytes("Saturday")
    };
    protected static final byte months[][] = {
        toBytes("Jan"), toBytes("Feb"), toBytes("Mar"), toBytes("Apr"), toBytes("May"), toBytes("Jun"), toBytes("Jul"), toBytes("Aug"), toBytes("Sep"), toBytes("Oct"), 
        toBytes("Nov"), toBytes("Dec")
    };
    protected static byte daysInMonth[] = {
        31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 
        30, 31
    };
    protected static byte daysInMonthLeap[] = {
        31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 
        30, 31
    };
    protected static short daysBeforeMonth[] = {
        0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 
        304, 334, 365
    };
    protected static short daysBeforeMonthLeap[] = {
        0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 
        305, 335, 366
    };
    private static final String DATESTR = "Sun, 06 Nov 1994 08:49:37 GMT";
    public static final int DATELEN = "Sun, 06 Nov 1994 08:49:37 GMT".length();
    protected static HttpDateUpdater updater;
    protected static int DAYS_PER_YEAR;
    protected static int DAYS_PER_LEAP;
    protected static int SECS_PER_MIN;
    protected static int SECS_PER_HOUR;
    protected static int SECS_PER_DAY;
    protected static int BASE_DAY_OF_WEEK = 4;

    static 
    {
        updater = new HttpDateUpdater(1000L);
        Thread thread = new Thread(updater);
        thread.setPriority(10);
        thread.start();
        DAYS_PER_YEAR = 365;
        DAYS_PER_LEAP = DAYS_PER_YEAR * 4 + 1;
        SECS_PER_MIN = 60;
        SECS_PER_HOUR = SECS_PER_MIN * 60;
        SECS_PER_DAY = SECS_PER_HOUR * 24;
    }
}