Parser for the common ISO 8061 date and timestamps.

gistfile1.java

    /**
     * Returns the timestamp parsed from the given ISO 8061 UTC string. Note
     * that all of the following timestamp forms are supported: {@code
     *
     * YYYY                       := YYYY-01-01T00:00:00.0Z
     * YYYY-MM                    := YYYY-MM-01T00:00:00.0Z
     * YYYY-MM-DD                 := YYYY-MM-DDT00:00:00.0Z
     * YYYY-MM-DD'T'HH            := YYYY-MM-DDTHH:00:00.0Z
     * YYYY-MM-DD'T'HH:MM         := YYYY-MM-DDTHH:MM:00.0Z
     * YYYY-MM-DD'T'HH:MM:SS      := YYYY-MM-DDTHH:MM:SS.0Z
     * YYYY-MM-DD'T'HH:MM:SS'Z'   := YYYY-MM-DDTHH:MM:SS.0Z
     * YYYY-MM-DD'T'HH:MM:SS.S    := YYYY-MM-DDTHH:MM:SS.SZ
     * YYYY-MM-DD'T'HH:MM:SS.S'Z' := YYYY-MM-DDTHH:MM:SS.SZ
     * }
     *
     * @param text is the external date or timestamp representation. Value must
     * not be null.
     */
    public static Timestamp parseValue(String text) throws ParseException {
        int year = 0;
        int month = 0;
        int day = 0;
        int hours = 0;
        int minutes = 0;
        int seconds = 0;
        int fractionalSeconds = 0;
        int state = 0;
        for (int i = 0; i < text.length(); i++) {
            char c = text.charAt(i);
            switch (state) {
                case 0:
                    // year
                    if (c == '-') {
                        state = 1;
                    }
                    else if ('0' <= c && c <= '9') {
                        year = year * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 1:
                    // month
                    if (c == '-') {
                        state = 2;
                    }
                    else if ('0' <= c && c <= '9') {
                        month = month * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 2:
                    // day
                    if (c == 'T') {
                        state = 3;
                    }
                    else if ('0' <= c && c <= '9') {
                        day = day * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 3:
                    // hours
                    if (c == ':') {
                        state = 4;
                    }
                    else if ('0' <= c && c <= '9') {
                        hours = hours * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 4:
                    // minutes
                    if (c == ':') {
                        state = 5;
                    }
                    else if ('0' <= c && c <= '9') {
                        minutes = minutes * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 5:
                    // seconds
                    if (c == '.') {
                        state = 6;
                    }
                    else if (c == 'Z') {
                        state = 7;
                    }
                    else if ('0' <= c && c <= '9') {
                        seconds = seconds * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 6:
                    // fractional seconds
                    if (c == 'Z') {
                        state = 7;
                    }
                    else if ('0' <= c && c <= '9') {
                        fractionalSeconds = fractionalSeconds * 10 + (c - '0');
                    }
                    else {
                        throw new ParseException(text, i);
                    }
                    continue;
                case 7:
                    throw new ParseException(text, i);
            }
        }
        // Note: Not using Calendar as it does not support fractional seconds.
        return new Timestamp(
                (year - 1900),
                (month == 0 ? 1 : (month - 1)),
                (day == 0 ? 1 : day),
                hours,
                minutes,
                seconds,
                fractionalSeconds);
    }