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/*
* Copyright (c) 2009 Albert Kurucz.
*
* This file, SpreadsheetDate.java is part of JTStand.
*
* JTStand 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 3 of the License, or
* (at your option) any later version.
*
* JTStand 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 GTStand. If not, see
* Be aware that there is a deliberate bug in Excel that recognises the year
* 1900 as a leap year when in fact it is not a leap year. You can find more
* information on the Microsoft website in article Q181370:
*
* http://support.microsoft.com/support/kb/articles/Q181/3/70.asp
*
* Excel uses the convention that 1-Jan-1900 = 1. This class uses the
* convention 1-Jan-1900 = 2.
* The result is that the day number in this class will be different to the
* Excel figure for January and February 1900...but then Excel adds in an extra
* day (29-Feb-1900 which does not actually exist!) and from that point forward
* the day numbers will match.
*
* @author David Gilbert
*/
public class SpreadsheetDate extends SerialDate {
/** For serialization. */
private static final long serialVersionUID = -2039586705374454461L;
/**
* The day number (1-Jan-1900 = 2, 2-Jan-1900 = 3, ..., 31-Dec-9999 =
* 2958465).
*/
private final int serial;
/** The day of the month (1 to 28, 29, 30 or 31 depending on the month). */
private final int day;
/** The month of the year (1 to 12). */
private final int month;
/** The year (1900 to 9999). */
private final int year;
/**
* Creates a new date instance.
*
* @param day the day (in the range 1 to 28/29/30/31).
* @param month the month (in the range 1 to 12).
* @param year the year (in the range 1900 to 9999).
*/
public SpreadsheetDate(final int day, final int month, final int year) {
if ((year >= 1900) && (year <= 9999)) {
this.year = year;
}
else {
throw new IllegalArgumentException(
"The 'year' argument must be in range 1900 to 9999."
);
}
if ((month >= MonthConstants.JANUARY)
&& (month <= MonthConstants.DECEMBER)) {
this.month = month;
}
else {
throw new IllegalArgumentException(
"The 'month' argument must be in the range 1 to 12."
);
}
if ((day >= 1) && (day <= SerialDate.lastDayOfMonth(month, year))) {
this.day = day;
}
else {
throw new IllegalArgumentException("Invalid 'day' argument.");
}
// the serial number needs to be synchronised with the day-month-year...
this.serial = calcSerial(day, month, year);
}
/**
* Standard constructor - creates a new date object representing the
* specified day number (which should be in the range 2 to 2958465.
*
* @param serial the serial number for the day (range: 2 to 2958465).
*/
public SpreadsheetDate(final int serial) {
if ((serial >= SERIAL_LOWER_BOUND) && (serial <= SERIAL_UPPER_BOUND)) {
this.serial = serial;
}
else {
throw new IllegalArgumentException(
"SpreadsheetDate: Serial must be in range 2 to 2958465.");
}
// the day-month-year needs to be synchronised with the serial number...
// get the year from the serial date
final int days = this.serial - SERIAL_LOWER_BOUND;
// overestimated because we ignored leap days
final int overestimatedYYYY = 1900 + (days / 365);
final int leaps = SerialDate.leapYearCount(overestimatedYYYY);
final int nonleapdays = days - leaps;
// underestimated because we overestimated years
int underestimatedYYYY = 1900 + (nonleapdays / 365);
if (underestimatedYYYY == overestimatedYYYY) {
this.year = underestimatedYYYY;
}
else {
int ss1 = calcSerial(1, 1, underestimatedYYYY);
while (ss1 <= this.serial) {
underestimatedYYYY = underestimatedYYYY + 1;
ss1 = calcSerial(1, 1, underestimatedYYYY);
}
this.year = underestimatedYYYY - 1;
}
final int ss2 = calcSerial(1, 1, this.year);
int[] daysToEndOfPrecedingMonth
= AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH;
if (isLeapYear(this.year)) {
daysToEndOfPrecedingMonth
= LEAP_YEAR_AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH;
}
// get the month from the serial date
int mm = 1;
int sss = ss2 + daysToEndOfPrecedingMonth[mm] - 1;
while (sss < this.serial) {
mm = mm + 1;
sss = ss2 + daysToEndOfPrecedingMonth[mm] - 1;
}
this.month = mm - 1;
// what's left is d(+1);
this.day = this.serial - ss2
- daysToEndOfPrecedingMonth[this.month] + 1;
}
/**
* Returns the serial number for the date, where 1 January 1900 = 2
* (this corresponds, almost, to the numbering system used in Microsoft
* Excel for Windows and Lotus 1-2-3).
*
* @return The serial number of this date.
*/
public int toSerial() {
return this.serial;
}
/**
* Returns a java.util.Date equivalent to this date.
*
* @return The date.
*/
public Date toDate() {
final Calendar calendar = Calendar.getInstance();
calendar.set(getYYYY(), getMonth() - 1, getDayOfMonth(), 0, 0, 0);
return calendar.getTime();
}
/**
* Returns the year (assume a valid range of 1900 to 9999).
*
* @return The year.
*/
public int getYYYY() {
return this.year;
}
/**
* Returns the month (January = 1, February = 2, March = 3).
*
* @return The month of the year.
*/
public int getMonth() {
return this.month;
}
/**
* Returns the day of the month.
*
* @return The day of the month.
*/
public int getDayOfMonth() {
return this.day;
}
/**
* Returns a code representing the day of the week.
*
* The codes are defined in the {@link SerialDate} class as:
* SUNDAY, MONDAY, TUESDAY,
* WEDNESDAY, THURSDAY, FRIDAY, and
* SATURDAY.
*
* @return A code representing the day of the week.
*/
public int getDayOfWeek() {
return (this.serial + 6) % 7 + 1;
}
/**
* Tests the equality of this date with an arbitrary object.
*
* This method will return true ONLY if the object is an instance of the
* {@link SerialDate} base class, and it represents the same day as this
* {@link SpreadsheetDate}.
*
* @param object the object to compare (null permitted).
*
* @return A boolean.
*/
public boolean equals(final Object object) {
if (object instanceof SerialDate) {
final SerialDate s = (SerialDate) object;
return (s.toSerial() == this.toSerial());
}
else {
return false;
}
}
/**
* Returns a hash code for this object instance.
*
* @return A hash code.
*/
public int hashCode() {
return toSerial();
}
/**
* Returns the difference (in days) between this date and the specified
* 'other' date.
*
* @param other the date being compared to.
*
* @return The difference (in days) between this date and the specified
* 'other' date.
*/
public int compare(final SerialDate other) {
return this.serial - other.toSerial();
}
/**
* Implements the method required by the Comparable interface.
*
* @param other the other object (usually another SerialDate).
*
* @return A negative integer, zero, or a positive integer as this object
* is less than, equal to, or greater than the specified object.
*/
public int compareTo(final Object other) {
return compare((SerialDate) other);
}
/**
* Returns true if this SerialDate represents the same date as the
* specified SerialDate.
*
* @param other the date being compared to.
*
* @return true if this SerialDate represents the same date as
* the specified SerialDate.
*/
public boolean isOn(final SerialDate other) {
return (this.serial == other.toSerial());
}
/**
* Returns true if this SerialDate represents an earlier date compared to
* the specified SerialDate.
*
* @param other the date being compared to.
*
* @return true if this SerialDate represents an earlier date
* compared to the specified SerialDate.
*/
public boolean isBefore(final SerialDate other) {
return (this.serial < other.toSerial());
}
/**
* Returns true if this SerialDate represents the same date as the
* specified SerialDate.
*
* @param other the date being compared to.
*
* @return true if this SerialDate represents the same date
* as the specified SerialDate.
*/
public boolean isOnOrBefore(final SerialDate other) {
return (this.serial <= other.toSerial());
}
/**
* Returns true if this SerialDate represents the same date as the
* specified SerialDate.
*
* @param other the date being compared to.
*
* @return true if this SerialDate represents the same date
* as the specified SerialDate.
*/
public boolean isAfter(final SerialDate other) {
return (this.serial > other.toSerial());
}
/**
* Returns true if this SerialDate represents the same date as the
* specified SerialDate.
*
* @param other the date being compared to.
*
* @return true if this SerialDate represents the same date as
* the specified SerialDate.
*/
public boolean isOnOrAfter(final SerialDate other) {
return (this.serial >= other.toSerial());
}
/**
* Returns true if this {@link SerialDate} is within the
* specified range (INCLUSIVE). The date order of d1 and d2 is not
* important.
*
* @param d1 a boundary date for the range.
* @param d2 the other boundary date for the range.
*
* @return A boolean.
*/
public boolean isInRange(final SerialDate d1, final SerialDate d2) {
return isInRange(d1, d2, SerialDate.INCLUDE_BOTH);
}
/**
* Returns true if this SerialDate is within the specified range (caller
* specifies whether or not the end-points are included). The order of d1
* and d2 is not important.
*
* @param d1 one boundary date for the range.
* @param d2 a second boundary date for the range.
* @param include a code that controls whether or not the start and end
* dates are included in the range.
*
* @return true if this SerialDate is within the specified
* range.
*/
public boolean isInRange(final SerialDate d1, final SerialDate d2,
final int include) {
final int s1 = d1.toSerial();
final int s2 = d2.toSerial();
final int start = Math.min(s1, s2);
final int end = Math.max(s1, s2);
final int s = toSerial();
if (include == SerialDate.INCLUDE_BOTH) {
return (s >= start && s <= end);
}
else if (include == SerialDate.INCLUDE_FIRST) {
return (s >= start && s < end);
}
else if (include == SerialDate.INCLUDE_SECOND) {
return (s > start && s <= end);
}
else {
return (s > start && s < end);
}
}
/**
* Calculate the serial number from the day, month and year.
*
* 1-Jan-1900 = 2.
*
* @param d the day.
* @param m the month.
* @param y the year.
*
* @return the serial number from the day, month and year.
*/
private int calcSerial(final int d, final int m, final int y) {
final int yy = ((y - 1900) * 365) + SerialDate.leapYearCount(y - 1);
int mm = SerialDate.AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH[m];
if (m > MonthConstants.FEBRUARY) {
if (SerialDate.isLeapYear(y)) {
mm = mm + 1;
}
}
final int dd = d;
return yy + mm + dd + 1;
}
}