date.java

来自「《移动Agent技术》一书的所有章节源代码。」· Java 代码 · 共 899 行 · 第 1/3 页

     * assumed. GMT and UTC are considered equivalent.
     *
     * @param   s   a string to be parsed as a date.
     * @return  the number of milliseconds since January 1, 1970, 00:00:00 GMT
     *          represented by the string argument.
     * @see     java.text.DateFormat
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>DateFormat.parse(String s)</code>.
     */
    public static long parse(String s) {
        int year = Integer.MIN_VALUE;
        int mon = -1;
        int mday = -1;
        int hour = -1;
        int min = -1;
        int sec = -1;
        int millis = -1;
        int c = -1;
        int i = 0;
        int n = -1;
        int wst = -1;
        int tzoffset = -1;
        int prevc = 0;
    syntax:
        {
            if (s == null)
                break syntax;
            int limit = s.length();
            while (i < limit) {
                c = s.charAt(i);
                i++;
                if (c <= ' ' || c == ',')
                    continue;
                if (c == '(') { // skip comments
                    int depth = 1;
                    while (i < limit) {
                        c = s.charAt(i);
                        i++;
                        if (c == '(') depth++;
                        else if (c == ')')
                            if (--depth <= 0)
                                break;
                    }
                    continue;
                }
                if ('0' <= c && c <= '9') {
                    n = c - '0';
                    while (i < limit && '0' <= (c = s.charAt(i)) && c <= '9') {
                        n = n * 10 + c - '0';
                        i++;
                    }
                    if (prevc == '+' || prevc == '-' && year != Integer.MIN_VALUE) {
                        // timezone offset
                        if (n < 24)
                            n = n * 60; // EG. "GMT-3"
                        else
                            n = n % 100 + n / 100 * 60; // eg "GMT-0430"
                        if (prevc == '+')   // plus means east of GMT
                            n = -n;
                        if (tzoffset != 0 && tzoffset != -1)
                            break syntax;
                        tzoffset = n;
                    } else if (n >= 70)
                        if (year != Integer.MIN_VALUE)
                            break syntax;
                        else if (c <= ' ' || c == ',' || c == '/' || i >= limit)
                            // year = n < 1900 ? n : n - 1900;
                            year = n;
                        else
                            break syntax;
                    else if (c == ':')
                        if (hour < 0)
                            hour = (byte) n;
                        else if (min < 0)
                            min = (byte) n;
                        else
                            break syntax;
                    else if (c == '/')
                        if (mon < 0)
                            mon = (byte) (n - 1);
                        else if (mday < 0)
                            mday = (byte) n;
                        else
                            break syntax;
                    else if (i < limit && c != ',' && c > ' ' && c != '-')
                        break syntax;
                    else if (hour >= 0 && min < 0)
                        min = (byte) n;
                    else if (min >= 0 && sec < 0)
                        sec = (byte) n;
                    else if (mday < 0)
                        mday = (byte) n;
                    // Handle two-digit years < 70 (70-99 handled above).
                    else if (year == Integer.MIN_VALUE && mon >= 0 && mday >= 0)
                        year = n;
                    else
                        break syntax;
                    prevc = 0;
                } else if (c == '/' || c == ':' || c == '+' || c == '-')
                    prevc = c;
                else {
                    int st = i - 1;
                    while (i < limit) {
                        c = s.charAt(i);
                        if (!('A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'))
                            break;
                        i++;
                    }
                    if (i <= st + 1)
                        break syntax;
                    int k;
                    for (k = wtb.length; --k >= 0;)
                        if (wtb[k].regionMatches(true, 0, s, st, i - st)) {
                            int action = ttb[k];
                            if (action != 0) {
                                if (action == 1) {  // pm
                                    if (hour > 12 || hour < 1)
                                        break syntax;
                                    else if (hour < 12)
                                        hour += 12;
                                } else if (action == 14) {  // am
                                    if (hour > 12 || hour < 1)
                                        break syntax;
                                    else if (hour == 12)
                                        hour = 0;
                                } else if (action <= 13) {  // month!
                                    if (mon < 0)
                                        mon = (byte) (action - 2);
                                    else
                                        break syntax;
                                } else {
                                    tzoffset = action - 10000;
                                }
                            }
                            break;
                        }
                    if (k < 0)
                        break syntax;
                    prevc = 0;
                }
            }
            if (year == Integer.MIN_VALUE || mon < 0 || mday < 0)
                break syntax;
            // Parse 2-digit years within the correct default century.
            if (year < 100) {
                year += (defaultCenturyStart / 100) * 100;
                if (year < defaultCenturyStart) year += 100;
            }
            year -= 1900;
            if (sec < 0)
                sec = 0;
            if (min < 0)
                min = 0;
            if (hour < 0)
                hour = 0;
            if (tzoffset == -1) // no time zone specified, have to use local
                return new Date (year, mon, mday, hour, min, sec).getTime();
            return UTC(year, mon, mday, hour, min, sec) + tzoffset * (60 * 1000);
        }
        // syntax error
        throw new IllegalArgumentException();
    }
    private final static String wtb[] = {
        "am", "pm",
        "monday", "tuesday", "wednesday", "thursday", "friday",
        "saturday", "sunday",
        "january", "february", "march", "april", "may", "june",
        "july", "august", "september", "october", "november", "december",
        "gmt", "ut", "utc", "est", "edt", "cst", "cdt",
        "mst", "mdt", "pst", "pdt"
        // this time zone table needs to be expanded
    };
    private final static int ttb[] = {
        14, 1, 0, 0, 0, 0, 0, 0, 0,
        2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
        10000 + 0, 10000 + 0, 10000 + 0,    // GMT/UT/UTC
        10000 + 5 * 60, 10000 + 4 * 60, // EST/EDT
        10000 + 6 * 60, 10000 + 5 * 60,
        10000 + 7 * 60, 10000 + 6 * 60,
        10000 + 8 * 60, 10000 + 7 * 60
    };

    /**
     * Returns the year represented by this date, minus 1900.
     *
     * @return  the year represented by this date, minus 1900.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.get(Calendar.YEAR) - 1900</code>.
     */
    public int getYear() {
        return getField(Calendar.YEAR) - 1900;
    }

    /**
     * Sets the year of this date to be the specified value plus 1900.
     *
     * @param   year    the year value.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.set(Calendar.YEAR, year + 1900)</code>.
     */
    public void setYear(int year) {
        setField(Calendar.YEAR, year + 1900);
    }

    /**
     * Returns the month represented by this date. The value returned is
     * between <code>0</code> and <code>11</code>, with the value
     * <code>0</code> representing January.
     *
     * @return  the month represented by this date.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.get(Calendar.MONTH)</code>.
     */
    public int getMonth() {
        return getField(Calendar.MONTH);
    }

    /**
     * Sets the month of this date to the specified value.
     *
     * @param   month   the month value between 0-11.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.set(Calendar.MONTH, int month)</code>.
     */
    public void setMonth(int month) {
        setField(Calendar.MONTH, month);
    }

    /**
     * Returns the day of the month represented by this date. The value
     * returned is between <code>1</code> and <code>31</code>.
     *
     * @return  the day of the month represented by this date.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.get(Calendar.DAY_OF_MONTH)</code>.
     * @deprecated
     */
    public int getDate() {
        return getField(Calendar.DATE);
    }

    /**
     * Sets the day of the month of this date to the specified value.
     *
     * @param   date   the day of the month value between 1-31.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.set(Calendar.DAY_OF_MONTH, int date)</code>.
     */
    public void setDate(int date) {
        setField(Calendar.DATE, date);
    }

    /**
     * Returns the day of the week represented by this date. The value returned
     * is between <code>0</code> and <code>6</code>, where <code>0</code>
     * represents Sunday.
     *
     * @return  the day of the week represented by this date.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.get(Calendar.DAY_OF_WEEK)</code>.
     */
    public int getDay() {
        return getField(Calendar.DAY_OF_WEEK) - Calendar.SUNDAY;
    }

    /**
     * Returns the hour represented by this date. The value returned is between
     * <code>0</code> and <code>23</code>, where <code>0</code> represents
     * midnight.
     *
     * @return  the hour represented by this date.
     * @see     java.util.Calendar
     * @since   JDK1.0
     * @deprecated As of JDK version 1.1,
     * replaced by <code>Calendar.get(Calendar.HOUR_OF_DAY)</code>.
     */
    public int getHours() {
        return getField(Calendar.HOUR_OF_DAY);
    }

    /**
     * Sets the hour of this date to the specified value.
     *
     * @param   hours   the hour value.
     * @see     java.util.Calendar