week.java

制作图表的好工具

     *
     * @return The serial index number.
     */
    public long getSerialIndex() {
        return this.year.getYear() * 53L + this.week;
    }

    /**
     * Returns the first millisecond of the week, evaluated using the supplied
     * calendar (which determines the time zone).
     *
     * @param calendar  the calendar.
     *
     * @return The first millisecond of the week.
     */
    public long getFirstMillisecond(Calendar calendar) {
        Calendar c = (Calendar) calendar.clone();
        c.clear();
        c.set(Calendar.YEAR, this.year.getYear());
        c.set(Calendar.WEEK_OF_YEAR, this.week);
        c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
        c.set(Calendar.HOUR, 0);
        c.set(Calendar.MINUTE, 0);
        c.set(Calendar.SECOND, 0);
        c.set(Calendar.MILLISECOND, 0);
        //return c.getTimeInMillis();  // this won't work for JDK 1.3
        return c.getTime().getTime();
    }

    /**
     * Returns the last millisecond of the week, evaluated using the supplied
     * calendar (which determines the time zone).
     *
     * @param calendar  the calendar.
     *
     * @return The last millisecond of the week.
     */
    public long getLastMillisecond(Calendar calendar) {
        RegularTimePeriod next = next();
        return next.getFirstMillisecond(calendar) - 1;
    }

    /**
     * Returns a string representing the week (e.g. "Week 9, 2002").
     *
     * TODO: look at internationalisation.
     *
     * @return A string representing the week.
     */
    public String toString() {
        return "Week " + this.week + ", " + this.year;
    }

    /**
     * Tests the equality of this Week object to an arbitrary object.  Returns
     * true if the target is a Week instance representing the same week as this
     * object.  In all other cases, returns false.
     * @param obj The object.
     *
     * @return <code>true</code> if week and year of this and object are the 
     *         same.
     */
    public boolean equals(Object obj) {

        if (obj == this) {
            return true;
        }
        if (!(obj instanceof Week)) {
            return false;
        }
        Week that = (Week) obj;
        if (this.week != that.week) {
            return false;
        }
        if (!this.year.equals(that.year)) {
            return false;
        }
        return true;

    }

    /**
     * Returns a hash code for this object instance.  The approach described by
     * Joshua Bloch in "Effective Java" has been used here:
     * <p>
     * <code>http://developer.java.sun.com/developer/Books/effectivejava
     * /Chapter3.pdf</code>
     * 
     * @return A hash code.
     */
    public int hashCode() {
        int result = 17;
        result = 37 * result + this.week;
        result = 37 * result + this.year.hashCode();
        return result;
    }

    /**
     * Returns an integer indicating the order of this Week object relative to
     * the specified object:
     *
     * negative == before, zero == same, positive == after.
     *
     * @param o1  the object to compare.
     *
     * @return negative == before, zero == same, positive == after.
     */
    public int compareTo(Object o1) {

        int result;

        // CASE 1 : Comparing to another Week object
        // --------------------------------------------
        if (o1 instanceof Week) {
            Week w = (Week) o1;
            result = this.year.getYear() - w.getYear().getYear();
            if (result == 0) {
                result = this.week - w.getWeek();
            }
        }

        // CASE 2 : Comparing to another TimePeriod object
        // -----------------------------------------------
        else if (o1 instanceof RegularTimePeriod) {
            // more difficult case - evaluate later...
            result = 0;
        }

        // CASE 3 : Comparing to a non-TimePeriod object
        // ---------------------------------------------
        else {
            // consider time periods to be ordered after general objects
            result = 1;
        }

        return result;

    }

    /**
     * Parses the string argument as a week.
     * <P>
     * This method is required to accept the format "YYYY-Wnn".  It will also
     * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
     *
     * @param s  string to parse.
     *
     * @return <code>null</code> if the string is not parseable, the week 
     *         otherwise.
     */
    public static Week parseWeek(String s) {

        Week result = null;
        if (s != null) {

            // trim whitespace from either end of the string
            s = s.trim();

            int i = Week.findSeparator(s);
            if (i != -1) {
                String s1 = s.substring(0, i).trim();
                String s2 = s.substring(i + 1, s.length()).trim();

                Year y = Week.evaluateAsYear(s1);
                int w;
                if (y != null) {
                    w = Week.stringToWeek(s2);
                    if (w == -1) {
                        throw new TimePeriodFormatException(
                            "Can't evaluate the week."
                        );
                    }
                    result = new Week(w, y);
                }
                else {
                    y = Week.evaluateAsYear(s2);
                    if (y != null) {
                        w = Week.stringToWeek(s1);
                        if (w == -1) {
                            throw new TimePeriodFormatException(
                                "Can't evaluate the week."
                            );
                        }
                        result = new Week(w, y);
                    }
                    else {
                        throw new TimePeriodFormatException(
                            "Can't evaluate the year."
                        );
                    }
                }

            }
            else {
                throw new TimePeriodFormatException(
                    "Could not find separator."
                );
            }

        }
        return result;

    }

    /**
     * Finds the first occurrence of ' ', '-', ',' or '.'
     *
     * @param s  the string to parse.
     *
     * @return <code>-1</code> if none of the characters was found, the
     *      index of the first occurrence otherwise.
     */
    private static int findSeparator(String s) {

        int result = s.indexOf('-');
        if (result == -1) {
            result = s.indexOf(',');
        }
        if (result == -1) {
            result = s.indexOf(' ');
        }
        if (result == -1) {
            result = s.indexOf('.');
        }
        return result;
    }

    /**
     * Creates a year from a string, or returns null (format exceptions
     * suppressed).
     *
     * @param s  string to parse.
     *
     * @return <code>null</code> if the string is not parseable, the year 
     *         otherwise.
     */
    private static Year evaluateAsYear(String s) {

        Year result = null;
        try {
            result = Year.parseYear(s);
        }
        catch (TimePeriodFormatException e) {
            // suppress
        }
        return result;

    }

    /**
     * Converts a string to a week.
     *
     * @param s  the string to parse.
     * @return <code>-1</code> if the string does not contain a week number,
     *         the number of the week otherwise.
     */
    private static int stringToWeek(String s) {

        int result = -1;
        s = s.replace('W', ' ');
        s = s.trim();
        try {
            result = Integer.parseInt(s);
            if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
                result = -1;
            }
        }
        catch (NumberFormatException e) {
            // suppress
        }
        return result;

    }
    
}