www.pudn.com > jworkbook-0.3.0.zip > SpreadsheetDate.java
/* ================================================= * JWorkbook : data export from Java to spreadsheets * ================================================= * * Project Info: http://www.jfree.org/jworkbook/index.html; * Project Lead: David Gilbert (david.gilbert@object-refinery.com); * * (C) Copyright 2001-2003, by Object Refinery Limited. * * 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., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * -------------------- * SpreadsheetDate.java * -------------------- * (C) Copyright 2000-2003, by Object Refinery Limited and Contributors. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * $Id: SpreadsheetDate.java,v 1.2 2003/06/05 08:07:07 mungady Exp $ * * Changes * ------- * 08-Jul-2003 : Version 1 copied from JCommon (DG); * */ package org.jfree.workbook.date; import java.io.Serializable; import java.util.Calendar; import java.util.Date; /** * Represents a date using an integer, in a similar fashion to the * implementation in Microsoft Excel. The range of dates supported is * 1-Jan-1900 to 31-Dec-9999. ** 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 implements Serializable { /** The day number (1-Jan-1900 = 2, 2-Jan-1900 = 3, ..., 31-Dec-9999 = 2958465). */ private int serial; /** The day of the month (1 to 28, 29, 30 or 31 depending on the month). */ private int day; /** The month of the year (1 to 12). */ private int month; /** The year (1900 to 9999). */ private int year; /** An optional description for the date. */ private String description; /** * Constructs a new spreadsheet date. * * @param day the day. * @param month the month (1-12). * @param year the year (in the range 1900 to 9999). */ public SpreadsheetDate(int day, int month, int year) { if ((year >= 1900) && (year <= 9999)) { this.year = year; } else { throw new IllegalArgumentException( "SpreadsheetDate: Year must be in range 1900 to 9999."); } if ((month >= SerialDate.JANUARY) && (month <= SerialDate.DECEMBER)) { this.month = month; } else { throw new IllegalArgumentException("SpreadsheetDate: Invalid month."); } if ((day >= 1) && (day <= SerialDate.lastDayOfMonth(month, year))) { this.day = day; } else { throw new IllegalArgumentException("SpreadsheetDate: Invalid day."); } // the serial number needs to be synchronised with the day-month-year... this.serial = calcSerial(day, month, year); this.description = null; } /** * 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(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... calcDayMonthYear(); } /** * Returns the description that is attached to the date. *
* It is not required that a date have a description, but for some applications it is useful. * * @return the description that is attached to the date. */ public String getDescription() { return this.description; } /** * Sets the description for the date. * * @param description the description for this date. */ public void setDescription(String description) { this.description = description; } /** * 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 this as
java.util.Date. */ public Date toDate() { 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 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 SpreadsheetDate with an arbitrary Object. *
* This method will return true ONLY if the object is an instance of the * SerialDate base class, and it represents the same day as this * SpreadsheetDate. * * @param object the object to compare. * * @return
trueif this is equal to object. */ public boolean equals(Object object) { if (object instanceof SerialDate) { SerialDate s = (SerialDate) object; return (s.toSerial() == this.toSerial()); } else { return false; } } /** * 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(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. * * @returntrueif this SerialDate represents the same date as the * specified SerialDate. */ public boolean isOn(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. * * @returntrueif this SerialDate represents an earlier date * compared to the specified SerialDate. */ public boolean isBefore(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. * * @returntrueif this SerialDate represents the same date * as the specified SerialDate. */ public boolean isOnOrBefore(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. * * @returntrueif this SerialDate represents the same date * as the specified SerialDate. */ public boolean isAfter(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. * * @returntrueif this SerialDate represents the same date as * the specified SerialDate. */ public boolean isOnOrAfter(SerialDate other) { return (this.serial >= other.toSerial()); } /** * Returns true if this SerialDate is within the specified range * (INCLUSIVE). The order of d1 d2 is not important. * * @param d1 one boundary date for the range. * @param d2 a second boundary date for the range. * * @returntrueif this SerialDate is within the specified range. */ public boolean isInRange(SerialDate d1, SerialDate d2) { return false; } /** * 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 iftrueinclude d2 in the search. * * @returntrueif this SerialDate is within the specified range. */ public boolean isInRange(SerialDate d1, SerialDate d2, int include) { return false; } /** * Calculate the serial number from the day, month and year. ** 1-Jan-1900 = 2. * * @param day the day. * @param month the month. * @param year the year. * * @return the serial number from the day, month and year. */ private int calcSerial(int day, int month, int year) { int y = ((year - 1900) * 365) + SerialDate.leapYearCount(year - 1); int m = SerialDate.AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH[month]; if (month > SerialDate.FEBRUARY) { if (SerialDate.isLeapYear(year)) { m = m + 1; } } int d = day; return y + m + d + 1; } /** * Calculate the day, month and year from the serial number. */ private void calcDayMonthYear() { // get the year from the serial date int days = this.serial - SERIAL_LOWER_BOUND; // overestimated because we ignored leap days int overestimatedYYYY = 1900 + (days / 365); int leaps = SerialDate.leapYearCount(overestimatedYYYY); 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; } 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; } }