Week.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ---------
* Week.java
* ---------
* (C) Copyright 2001-2022, by David Gilbert and Contributors.
*
* Original Author: David Gilbert;
* Contributor(s): Aimin Han;
*
*/
package org.jfree.data.time;
import java.io.Serializable;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import org.jfree.chart.internal.Args;
/**
* A calendar week. All years are considered to have 53 weeks, numbered from 1
* to 53, although in many cases the 53rd week is empty. Most of the time, the
* 1st week of the year *begins* in the previous calendar year, but it always
* finishes in the current year (this behaviour matches the workings of the
* {@code GregorianCalendar} class).
* <P>
* This class is immutable, which is a requirement for all
* {@link RegularTimePeriod} subclasses.
*/
public class Week extends RegularTimePeriod implements Serializable {
/** For serialization. */
private static final long serialVersionUID = 1856387786939865061L;
/** Constant for the first week in the year. */
public static final int FIRST_WEEK_IN_YEAR = 1;
/** Constant for the last week in the year. */
public static final int LAST_WEEK_IN_YEAR = 53;
/** The year in which the week falls. */
private short year;
/** The week (1-53). */
private byte week;
/** The first millisecond. */
private long firstMillisecond;
/** The last millisecond. */
private long lastMillisecond;
/**
* Creates a new time period for the week in which the current system
* date/time falls.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*/
public Week() {
this(new Date());
}
/**
* Creates a time period representing the week in the specified year.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param week the week (1 to 53).
* @param year the year (1900 to 9999).
*/
public Week(int week, int year) {
if ((week < FIRST_WEEK_IN_YEAR) || (week > LAST_WEEK_IN_YEAR)) {
throw new IllegalArgumentException(
"The 'week' argument must be in the range 1 - 53.");
}
this.week = (byte) week;
this.year = (short) year;
peg(getCalendarInstance());
}
/**
* Creates a time period representing the week in the specified year.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param week the week (1 to 53).
* @param year the year (1900 to 9999).
*/
public Week(int week, Year year) {
if ((week < FIRST_WEEK_IN_YEAR) || (week > LAST_WEEK_IN_YEAR)) {
throw new IllegalArgumentException(
"The 'week' argument must be in the range 1 - 53.");
}
this.week = (byte) week;
this.year = (short) year.getYear();
peg(getCalendarInstance());
}
/**
* Creates a time period for the week in which the specified date/time
* falls.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
* The locale can affect the day-of-the-week that marks the beginning
* of the week, as well as the minimal number of days in the first week
* of the year.
*
* @param time the time ({@code null} not permitted).
*
* @see #Week(Date, TimeZone, Locale)
*/
public Week(Date time) {
// defer argument checking...
this(time, getCalendarInstance());
}
/**
* Creates a time period for the week in which the specified date/time
* falls, calculated relative to the specified time zone.
*
* @param time the date/time ({@code null} not permitted).
* @param zone the time zone ({@code null} not permitted).
* @param locale the locale ({@code null} not permitted).
*
* @since 1.0.7
*/
public Week(Date time, TimeZone zone, Locale locale) {
Args.nullNotPermitted(time, "time");
Args.nullNotPermitted(zone, "zone");
Args.nullNotPermitted(locale, "locale");
Calendar calendar = Calendar.getInstance(zone, locale);
calendar.setTime(time);
// sometimes the last few days of the year are considered to fall in
// the *first* week of the following year. Refer to the Javadocs for
// GregorianCalendar.
int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
if (tempWeek == 1
&& calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
this.week = 1;
this.year = (short) (calendar.get(Calendar.YEAR) + 1);
}
else {
this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
int yyyy = calendar.get(Calendar.YEAR);
// alternatively, sometimes the first few days of the year are
// considered to fall in the *last* week of the previous year...
if (calendar.get(Calendar.MONTH) == Calendar.JANUARY
&& this.week >= 52) {
yyyy--;
}
this.year = (short) yyyy;
}
peg(calendar);
}
/**
* Constructs a new instance, based on a particular date/time.
* The time zone and locale are determined by the {@code calendar}
* parameter.
*
* @param time the date/time ({@code null} not permitted).
* @param calendar the calendar to use for calculations ({@code null} not permitted).
*/
public Week(Date time, Calendar calendar) {
calendar.setTime(time);
// sometimes the last few days of the year are considered to fall in
// the *first* week of the following year. Refer to the Javadocs for
// GregorianCalendar.
int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
if (tempWeek == 1
&& calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
this.week = 1;
this.year = (short) (calendar.get(Calendar.YEAR) + 1);
}
else {
this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
int yyyy = calendar.get(Calendar.YEAR);
// alternatively, sometimes the first few days of the year are
// considered to fall in the *last* week of the previous year...
if (calendar.get(Calendar.MONTH) == Calendar.JANUARY
&& this.week >= 52) {
yyyy--;
}
this.year = (short) yyyy;
}
peg(calendar);
}
/**
* Returns the year in which the week falls.
*
* @return The year (never {@code null}).
*/
public Year getYear() {
return new Year(this.year);
}
/**
* Returns the year in which the week falls, as an integer value.
*
* @return The year.
*/
public int getYearValue() {
return this.year;
}
/**
* Returns the week.
*
* @return The week.
*/
public int getWeek() {
return this.week;
}
/**
* Returns the first millisecond of the week. This will be determined
* relative to the time zone specified in the constructor, or in the
* calendar instance passed in the most recent call to the
* {@link #peg(Calendar)} method.
*
* @return The first millisecond of the week.
*
* @see #getLastMillisecond()
*/
@Override
public long getFirstMillisecond() {
return this.firstMillisecond;
}
/**
* Returns the last millisecond of the week. This will be
* determined relative to the time zone specified in the constructor, or
* in the calendar instance passed in the most recent call to the
* {@link #peg(Calendar)} method.
*
* @return The last millisecond of the week.
*
* @see #getFirstMillisecond()
*/
@Override
public long getLastMillisecond() {
return this.lastMillisecond;
}
/**
* Recalculates the start date/time and end date/time for this time period
* relative to the supplied calendar (which incorporates a time zone
* and information about what day is the first day of the week).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @since 1.0.3
*/
@Override
public void peg(Calendar calendar) {
this.firstMillisecond = getFirstMillisecond(calendar);
this.lastMillisecond = getLastMillisecond(calendar);
}
/**
* Returns the week preceding this one. This method will return
* {@code null} for some lower limit on the range of weeks (currently
* week 1, 1900). For week 1 of any year, the previous week is always week
* 53, but week 53 may not contain any days (you should check for this).
* No matter what time zone and locale this instance was created with,
* the returned instance will use the default calendar for time
* calculations, obtained with {@link RegularTimePeriod#getCalendarInstance()}.
*
* @return The preceding week (possibly {@code null}).
*/
@Override
public RegularTimePeriod previous() {
Week result;
if (this.week != FIRST_WEEK_IN_YEAR) {
result = new Week(this.week - 1, this.year);
}
else {
// we need to work out if the previous year has 52 or 53 weeks...
if (this.year > 1900) {
int yy = this.year - 1;
Calendar prevYearCalendar = getCalendarInstance();
prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
result = new Week(prevYearCalendar.getActualMaximum(
Calendar.WEEK_OF_YEAR), yy);
}
else {
result = null;
}
}
return result;
}
/**
* Returns the week following this one. This method will return
* {@code null} for some upper limit on the range of weeks (currently
* week 53, 9999). For week 52 of any year, the following week is always
* week 53, but week 53 may not contain any days (you should check for
* this).
* No matter what time zone and locale this instance was created with,
* the returned instance will use the default calendar for time
* calculations, obtained with {@link RegularTimePeriod#getCalendarInstance()}.
*
* @return The following week (possibly {@code null}).
*/
@Override
public RegularTimePeriod next() {
Week result;
if (this.week < 52) {
result = new Week(this.week + 1, this.year);
}
else {
Calendar calendar = getCalendarInstance();
calendar.set(this.year, Calendar.DECEMBER, 31);
int actualMaxWeek
= calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
if (this.week < actualMaxWeek) {
result = new Week(this.week + 1, this.year);
}
else {
if (this.year < 9999) {
result = new Week(FIRST_WEEK_IN_YEAR, this.year + 1);
}
else {
result = null;
}
}
}
return result;
}
/**
* Returns a serial index number for the week.
*
* @return The serial index number.
*/
@Override
public long getSerialIndex() {
return this.year * 53L + this.week;
}
/**
* Returns the first millisecond of the week, evaluated using the supplied
* calendar (which determines the time zone).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @return The first millisecond of the week.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getFirstMillisecond(Calendar calendar) {
Calendar c = (Calendar) calendar.clone();
c.clear();
c.set(Calendar.YEAR, this.year);
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();
}
/**
* Returns the last millisecond of the week, evaluated using the supplied
* calendar (which determines the time zone).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @return The last millisecond of the week.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getLastMillisecond(Calendar calendar) {
Calendar c = (Calendar) calendar.clone();
c.clear();
c.set(Calendar.YEAR, this.year);
c.set(Calendar.WEEK_OF_YEAR, this.week + 1);
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() - 1;
}
/**
* Returns a string representing the week (e.g. "Week 9, 2002").
*
* TODO: look at internationalisation.
*
* @return A string representing the week.
*/
@Override
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 ({@code null} permitted).
*
* @return {@code true} if week and year of this and object are the
* same.
*/
@Override
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 != 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}
*
* @return A hash code.
*/
@Override
public int hashCode() {
int result = 17;
result = 37 * result + this.week;
result = 37 * result + this.year;
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.
*/
@Override
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 - 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} 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} 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} 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} 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;
}
}